BUILDING CONTROL GUIDANCE FOR DOMESTIC LOFT CONVERSIONS

Transcription

1 BUILDING CONTROL GUIDANCE FOR DOMESTIC LOFT CONVERSIONS OCTOBER 2010 EDITION 4-1 -

2 Introduction This document intends to provide education and guidance on how some of the technical design and construction requirements of the Building Regulations 2010 can be achieved and met for loft conversions to dwellings up to two storeys in height and within 4.5m of ground level and additional guidance is given for three storeys in height which has a floor 4.5m above ground level. For loft conversions of four storeys or more with more than one floor above 4.5m please contact building control for advice. In all cases the design and construction of the proposed works is the responsibility of the designer, applicant and contractor and should be carried out to the relevant submitted and approved design. For further information reference should be made to the relevant Approved Document or standard as well as consulting a suitably qualified and experienced construction professional. The Approved Documents listed below are available to purchase from The Stationary Office (TSO) on line at or telephone: However, the Building Regulation requirements may be satisfied in other ways or non-standard ways by calculations or test details from a manufacturer or an approved 3rd party method of certification such as BBA (British Board of Agreement) Certificate. This document can be made available on a range of other formats if required. For further information please contact us on Approved Documents and sections they cover; A: Structure (2004 edition) including TRADA span tables for solid timber members in floors, ceilings and roofs for dwellings (2nd edition 2008)*; B1: Fire safety in dwelling houses (2006 edition); C: Site preparation and resistance to contaminants & moisture (2004 edition); D: Toxic substances (1992 with 2002 amendments); E: Resistance to the passage of sound (2003 with 2004 amendments); F: Ventilation (2010 edition); G: Sanitation, hot water safety and water efficiency (2010 edition); H: Drainage and waste disposal (2002 edition); J: Combustion appliances & fuel storage systems (2010 edition); K: Protection from falling, collision and impact (1998 with 2002 amendments); L1B: Conservation of fuel and power in existing dwellings (2010 edition); N: Glazing Safety in relation to impact, opening & cleaning (1998 with 2000 amendments); P: Electrical safety (2006 edition); Regulation 7 Materials and workmanship (1992 with 2000 amendments). Other guidance documents available: New Dwellings, New extensions Commercial/industrial buildings & Fire Safety for Conversion of buildings into Holiday Lets, Guest Houses & Supervised Groups with Learning Difficulties. Important note: Typical section details have been provided in these guidance notes for the more common construction methods used in dwellings. These details are suggested methods of construction and are for guidance only. You are advised to contact a suitably qualified and experienced property professional for details and specifications for the most suitable form and method of construction for your project

3 CONTENTS PAGE NUMBER INTRODUCTION CONVERTING AN EXISTING LOFT SPACE ENGAGING A PROPERTY PROFESSIONAL 3.0 OBTAINING BUILDING REGULATIONS APPROVAL 3.1 full plans application 3.2 building notice application EXEMPT BUILDINGS AND WORK 5.0 COMPETENT PERSON SCHEME 6.0 PLANNING PERMISSION, LISTED BUILDING & CONSERVATION AREA CONSENTS THE PARTY WALL ACT CONSTRUCTION (DESIGN AND MANAGEMENT) REGULATIONS 2007 (CDM) 9.0 ASSESSING THE FEASIBILITY OF YOUR LOFT CONVERSION GENERAL TECHNICAL & PRACTICAL GUIDANCE FOR LOFT CONVERSIONS 10 A1: PREPARATION, PROTECTION, ACCESS & DEMOLITION A2: INSPECTION OF THE EXISTING ROOF & STRUCTURE A3: ALTERATION, MODIFICATION & STRENGTHENING OF THE EXISTING ROOF/STRUCTURE Diagram 1: Typical plan layout of a loft conversion with dormer pitched roof 11 Diagram 2: Typical section through a loft conversion with dormer pitched roof 12 Diagram 3: Typical section through a loft conversion with dormer flat roof A4: NEW PITCHED ROOFS 13 Pitched roof coverings Pitched roof structure Roof trusses (including attic & girder trusses) Cut roof construction Table 1: Spans for Common Domestic Timber Rafter Sizes at 400mm spacing 14 Table 2: Spans for Common Domestic Timber Ceiling Joist Sizes at 400mm spacing Table 3: Spans for Common Domestic Timber Purlin Sizes Table 4: Permissible Clear Spans for Common Ceiling Binders Sizes 15 Diagram 4: Typical section through a pitched roof Roof restraint Roof insulation 16 Table 5: Insulation laid horizontally between and over ceiling joists Table 6: Insulation fixed between/under rafters Table 7: Insulation fixed between/over rafters Diagram 5: Typical roof valley detail 17 Diagram 6: Typical section through a dormer roof Roof ventilation 18 A5: FLAT ROOF CONSTRUCTION Diagram 7: Typical section through a flat (cold) roof 19 Table 8: Spans for Common Flat Roof Joist Sizes Table 9: Insulation Fixed Between/Under Flat Roof Joists 20 Table 10: Insulation Fixed above Flat Roof Joists Valleys and lead work Lofts hatches, doors & Light wells to roof spaces A6: NEW EXTERNAL WALLS 21 Cavity walls Table11: Insulation requirements for external cavity walls External timber framed walls with render finish 22 Diagram 8: Typical section through external timber framed walls with render finish External timber framed walls with cladding finish Diagram 9: Typical section through external timber framed walls with cladding finish 23 Wall abutments Lintels & weep holes Structural columns/beams etc Expansion joints Strapping and restraint Cavity closers A7: INTERNAL LOAD BEARING WALLS 24 Internal load bearing timber stud walls Diagram 10: Typical section through internal load bearing timber stud wall supporting roof loads Table 12 : Insulation requirements to exposed timber framed walls Internal load bearing masonry partitions A8: INTERNAL NON LOAD BEARING PARTITIONS 25 Internal masonry non-load bearing partitions Internal timber studwork non-load bearing partitions - 3 -

4 A9: UPGRADING EXISTING EXTERNAL WALLS 26 Diagram 11: Typical plan layout of upgrading existing walls in loft conversion Table 13: Insulation requirements for upgrading existing external walls A10: SEPARATING (PARTY) WALLS & FLOORS BETWEEN DWELLINGS 27 Masonry party walls separating dwellings Timber frame party walls separating buildings Upgrading sound insulation of existing separating walls Party floors separating buildings Sound testing requirements A11: ADDITIONAL PROVISIONS FOR 3 STOREY BUILDINGS/EXTENSIONS 28 Compressive strength of masonry units A12: INTERMEDIATE UPPER FLOOR(S) Diagram 12: Typical section through a loft floor Diagram 13: Typical section through an upper floor 29 Table 14: Spans for Common Domestic Floor Joist Sizes Table 15: Spans for Common Trimmer Joist supporting Trimmed Joists Table 16: Spans for Common Trimming Joist supporting Trimmer Joist Sound insulation to floors within the dwelling 30 SVP pipe boxing Exposed intermediate upper floors Table 17: Insulation requirements to exposed intermediate floors PART B: FIRE SAFETY & MEANS OF ESCAPE 31 MEANS OF ESCAPE FROM SINGLE STOREY DWELLING WITH NEW SECOND STOREY MEANS OF ESCAPE FROM TWO STOREY DWELLINGS WITH NEW THIRD STOREY 32 Option 1: Protected stairway Option 2: Protected stairway with alternative exits at ground floor level 33 Option 3: Fire separated 3 rd storey with alternative external/internal fire exit 34 Option 4: Residential sprinkler systems for means of escape 35 Fire doors Smoke alarms Fire resistance to new storey floor 36 Permitted building openings in relation to a boundary: Openings within 1.0m of a boundary Openings more than 1.0m from a boundary Table 18: Permitted unprotected areas in relation to a relevant boundary Fire resistance to elements of structure etc Table 19: Fire resistance to common elements of structure etc Surface spread of flame: wall & ceiling linings 37 Table 20: Surface spread of flame: Classification of wall & ceiling linings PART C: SITE PREPARATION AND RESISTANCE TO CONTAMINANTS & MOISTURE 38 Horizontal damp proof courses & trays (dpc s) Vertical damp proof courses & trays etc (dpc s) PART D: CAVITY WALL FILLING WITH INSULATION BY SPECIALISTS PART E: RESISTANCE TO THE PASSAGE OF SOUND New Internal walls & floors in loft conversion New/existing party walls and floors in loft conversion PART F: VENTILATION 39 Purge (natural) ventilation Mechanical extract ventilation & fresh air inlets for rooms without purge ventilation Background ventilation Mechanical extract ventilation rates General requirements for mechanical extract ventilation PART G: SANITATION, HOT WATER SAFETY AND WATER EFFICIENCY 40 PART H: DRAINAGE AND WASTE DISPOSAL 41 H1: FOUL WATER DRAINAGE Foul, rain & storm water drainage systems Waste pipes H2: SEPTIC TANKS, SEWAGE TREATMENT SYSTEMS & CESSPOOLS 42 Existing septic tank & effluent drainage Non mains foul drainage waste water treatment systems Septic tanks Sewage treatment systems 43 Treatment of sewage from septic tanks & sewage treatment systems Drainage fields Drainage mounds Wetlands/reed beds 44 Percolation test method to calculate area of drainage field for septic tanks or sewage treatment systems. Diagram 14: Typical section through a septic tank/sewage treatment system drainage field 45 Diagram 15 : Typical drainage field plan layout (not to scale) - 4 -

5 H3: RAINWATER DRAINAGE AND HARVESTING 46 Rainwater gutters and down pipes Table 21: Gutter sizes & pipe outlet sizes for drainage of roof areas Rainwater/ grey water harvesting storage tanks & systems Surface water drainage around the building PART J: COMBUSTION APPLIANCES & FUEL STORAGE SYSTEMS 47 SPACE & HOT WATER HEAT PRODUCING APPLIANCES IN GENERAL SOLID FUEL APPLIANCES UP TO 50KW RATED OUTPUT Construction of open fire place with recess & hearth Free standing stove with hearth Air supply (ventilation) to solid fuel appliances Table 22: Air supply (ventilation) to solid fuel appliances 48 Carbon monoxide alarms Table 23: Sizes of flues in chimneys Construction of masonry chimneys 49 Construction of factory made flue block chimneys Construction of factory made metal chimneys Configuration of flues serving open flue appliances Inspection & cleaning openings in flues Interaction of mechanical extract vents & opened flue solid fuel appliances Chimney heights 50 Repair/relining of existing flues Notice plates for hearths & flues APPLIANCES OTHER THAN SOLID FUEL Interaction of mechanical extract vents & opened flue combustion appliances Gas appliances Oil appliances Gas heating appliances up to 70kw Oil heating appliances up to 45kW 51 Renewable energy Installations PROVISION OF INFORMATION- COMMISSIONING CERTIFICATES (TESTING) FUEL STORAGE TANKS LPG tanks and cylinders up to 1.1 tonnes Oil tanks up to 3500 litres PART K: PROTECTION FROM FALLING, COLLISION AND IMPACT 52 STAIRS, LANDINGS AND CHANGES IN LEVEL OF 600MM OR MORE (INCLUDING EXTERNAL STEPS) Diagram 16: Measuring rise & goings Diagram 17: Typical internal stair case & guarding construction details 53 GUARDING TO EXTERNAL STEPPED ACCESS, BALCONIES, FLAT ROOFS & LOW LEVEL WINDOW OPENINGS PART L: CONSERVATION OF FUEL AND POWER IN EXISTING DWELLINGS 54 LISTED BUILDINGS, CONSERVATION AREAS & ANCIENT MONUMENTS AREAS OF EXTERNAL WINDOWS, ROOF WINDOWS & DOORS NEW THERMAL ELEMENTS External glazing Table 24: U Values for new external windows & doors including roof windows Closing around window & door openings Sealing Measures External Walls, roofs, floors & swimming pool basin 55 Table 25: U Values for new external walls, roofs, floors & swimming pool basin RENOVATION/UPGRADING OF EXISTING THERMAL ELEMENTS Table 26: Renovation/upgrading of existing thermal elements Payback report ENERGY EFFICIENT LIGHTING 56 Fixed internal lighting Fixed external lighting CONSEQUENTIAL IMPROVEMENTS COMMISSIONING OF FIXED BUILDING SERVICES PROVIDING INFORMATION -BUILDING LOG BOOK PART N: SAFETY GLAZING, OPENING & CLEANING 57 Safety glass and glazing Diagram 18: Glazing in windows, partitions, doors, side panels/screens & walls PART P: ELECTRICAL SAFETY 58 Electrical Installations EXTERNAL WORKS- PATHS, DRIVES, PATIO & GARDENS 59 MATERIALS AND WORKMANSHIP 60 ADDITIONAL BUILDING CONTROL SERVICES WE CAN PROVIDE GLOUCESTERSHIRE BUILDING CONTROL DEPARTMENTS CONTACT DETAILS 61 USEFUL NUMBERS OF OTHER AGENCIES OR COMPANIES - 5 -

6 1.0 Converting an existing loft space Converting an existing loft space can be an easy and cost effective way of increasing living accommodation in most houses. This guide to loft conversions will provide useful guidance on how some of the technical design and construction requirements of the Building Regulations can be achieved where the loft space of an existing one or two storey dwelling is being converted into habitable accommodation to form an additional storey to the dwelling. Where the house has three or more storeys before the loft is converted -please contact building control for further guidance. 2.0 Engaging a property professional This type of work can be complex and unless you are experienced in construction you will need to get some professional advice from the following: 1. Appointing a suitably qualified and experienced property professional who will prepare drawings and designs for your proposal, obtain the necessary approvals and if required they will also help you to find a suitable builder and manage the project for you. 2. Appointing a specialist company who can offer a one stop shop for this type of work, they can prepare drawings and designs for your proposal, obtain the necessary approvals and carry out all the necessary construction works to complete the project. 3. Using an experienced builder. 3.0 Obtaining Building Regulations approval The building owner or agent must make a building regulations application & pay a fee for the proposed works. All work must comply with the 2010 Building Regulations and the technical design and constructional requirements of the current Approved Documents A to P and Regulation - 7 Materials and Workmanship. The person carrying out the building works is to liaise with and meet the requirements of the LA Building Control/Certifying Body, giving required notices of stages of works as required by the Building Regulations including: Foundation excavations before any concrete is laid Over site covering to ground floors before any concrete is laid Foul & surface water drainage before any pipes are covered over Structural timbers (upper storey floor joists/beams and roof structure before any coverings are fixed Completion of building-prior to occupation There are two methods of making a Building Regulations application as follows: 3.1 Full Plans application This is often thought of as the traditional way of applying for Building Regulations Approval. The building designer will draw up detailed plans and supporting information for the proposed scheme and will send them to us together with a completed application form and the necessary fee which are available to down load from our web site at: We will then check the details and following any necessary consultations and liaisons with the building designer a Building Regulations Approval will be issued. Work can start any time after the application has been received although it is wise to wait until the scheme has had its initial check under the Building Regulations, this usually takes between two and three weeks

7 Our team of surveyors will liaise with your builder and inspect the work as it progresses on site. When the project is satisfactorily completed a Building Regulations Completion Certificate will be issued showing that the project has been independently inspected and that it complied with the Building Regulations. 3.2 Building Notice application This system is best suited to minor domestic work carried out by a competent builder. Under this scheme no formal Approval of plans is issued and work is approved on site as it progresses. To use the Building Notice process you or your agent will need to submit a completed Building Notice application form together with a site location plan and the required fee. The application forms are available to down load from our web site at: Work can commence 48 hours after the notice has been received. When work commences one of our surveyors will meet with your builder to discuss your intentions, to agree how the work should be carried out, agree when the work will need to be inspected and to establish whether any further information will be required. When the project is satisfactorily completed a Building Regulations Completion Certificate will be issued showing that the project has been independently inspected and that it complied with the Building Regulations. 4.0 Exempt buildings and work Green Houses & agricultural buildings: Buildings used for agriculture or keeping of animals providing no part is used as as a dwelling and is more than 1.5 times its height from a building containing sleeping accommodation Temporary buildings: Buildings erected for less than 28 days Ancillary buildings: Buildings used in connection with the sale of buildings or plots on that site, or in connection with a building project or mine/quarry and contains no sleeping accommodation. Small detached buildings (garages, workshops or sheds): A detached single storey building with less than 30m 2 internal floor area, with no sleeping accommodation. If constructed substantially of combustible materials it must be positioned at least one metre from the boundary of its cartilage. Other detached buildings with less than 15m 2 internal floor area, with no sleeping accommodation. (no boundary restrictions if constructed of combustible materials) Conservatory, porch, covered yard/way & carports: A detached single storey building with less than 30m 2 internal floor area, fitted with safety glass in critical locations in compliance with ADN. Existing walls, doors & windows of the building separating the conservatory or porch is to be retained or, if removed are replaced with elements that meet the energy efficiency requirements of ADL1B. The heating system of the dwelling must not be extended into the conservatory or porch. Carports must be open on two sides. 5.0 Competent Person Scheme Certain works can be carried out by an installer who is registered with a Competent Persons Scheme and will not require building regulations approval. For a list of all scheme members go to

8 6.0 Planning Permission, listed building & conservation area consents Planning permission, listed building/conservation area consents may be required for your proposed development and no works should be commenced until approval has been given by the planning department. If the requirements of the building regulations will unacceptably alter the character or appearance of a historic/listed building/ancient monument or building within a conservation area, then the requirements may be exempt or improved to what is reasonably practical or acceptable and would not increase the risk of deterioration of the building fabric or fittings in consultation with the local planning authorities conservation officer. For any further information, please contact the FODDC duty planning officer on The Party Wall Act 1996 If the project affects a party wall, you may be required to give your neighbor the required notice under the Party Wall Act. Two months notice in writing is to be given to adjoining owner(s) for the following works to an existing Party Wall: Support of beam Insert DPC through wall Raise wall or cut off projections Demolition and rebuilding Underpinning Insert lead flashings Excavations within 3 meters of an existing structure where the new foundations will go deeper than adjoining foundations, or within 6 meters of an existing structure where the new foundations are within a 45 degree line of the adjoining foundations. In the event of a disagreement, a Party Wall Surveyor may be required to resolve the dispute under the terms of the Party Wall Act. Copies of the Party Wall Act can be obtained from the Council Offices or Construction (Design and Management) Regulations 2007 (CDM) The Construction (Design and Management) Regulations 2007 apply to every construction project. If you are about to undertake construction work, which could include alterations, extensions, routine maintenance, new build or demolitions, then you need to know to what extent these Regulations will apply to you and whether you are a duty holder under these Regulations. With non-domestic* projects expected to last longer than 30 days, or more than 500 man hours, you will require the assistance of an advisor called a CDM Co-ordinator, who should be appointed at the earliest opportunity, before detailed design work is complete. If you are a Client thinking of commissioning work, a Designer appointed to work on a project, or a builder/developer about to undertake work, you should be aware of your responsibilities or duties under CDM *Non-domestic Clients are people who commission building works related to a trade or business, whether for profit or not. This work can be carried out on a domestic property; it is the type of Client that matters, not the type of property

9 9.0 Assessing the feasibility of your loft conversion Before commencing a loft conversion it is important to assess the feasibility of the project. This will involve inspection of the existing loft & dwelling to assess the following: Roof structure & shape- The overall form, construction and profile of the roof will have a major bearing on the whether the roof is suitable for conversion to a usable space. Traditional cut timber pitched roofs with gable ends walls (cavity walls or solid walls at least 250mm thick) and horizontal ridges are generally easier to convert and can normally support structural beams than hipped roofs or roofs with intersecting pitches and valleys which may require more complicated structural designs. Trussed rafter roofs constructed using a series of complex trusses should only be altered, modified and converted in compliance with details and calculations carried out by a suitable qualified and experience property professional. No trussed rafter should ever be cut or modified in any way until a new supporting structure is in place which has been designed by a suitably qualified and experienced specialist designer. Further information for loft conversions with trussed rafter roofs can be obtained from TRADA at: All existing timbers should be in a sound condition, any defective timber is to be replaced with new in compliance with details and calculations carried out by a suitable qualified and experience property professional. Existing timbers are to be inspected and where necessary treated against insect and fungal attack by a suitable qualified and experience specialist. Roof Coverings & roofing felt - Should be in a sound and weather tight condition; any defective coverings/felt should be replaced with matching new/existing sound coverings, fixed as manufacturer s details. Ceilings- To the underside of the new storey floor should achieve 30 minutes fire resistance. Normally 13mm plaster board & skim or sound lath and plaster in older houses will achieve this, otherwise additional upgrading will be required. Internal space available The roof space should not have any chimneys or services passing centrally through the loft space that cannot be easily moved, altered or modified by suitable experienced and qualified property professionals. Structural alterations/modifications should be in compliance with details and calculations carried out by a suitable qualified and experience property professional. Head room available- Is measured vertically from the top of the new floor (which typically can be 200mm above the existing ceiling joists) to the underside of the new horizontal/sloping ceilings (which can typically down stand 50-75mm from the existing roof structure). A minimum headroom of 2.0m is required at the head of the stairs to comply with building regulations. A ceiling height of 2.2 to 2.3 is preferred in the centre of the roof in habitable rooms reducing to to 1.2m for the side walls on sloping ceilings so low furniture can be placed in front of them. If your existing roof pitch is less than 30 degrees and roof span is less than 6 metres, a loft conversion may be impractical and the only possibility may be to remove the roof completely and replace it with attic trusses suitable for rooms in the roof designed by a specialist. Means of escape- Three storey houses will require a protected stairs that connects to a hall and final exit at ground floor level or give access to at least two escape routes to final exits at ground level which will require separated by fire resisting construction and fire doors. Alternatively, the new top storey can be separated by fire resisting construction and provided with an alternative escape route (subject to planning permission), or a domestic sprinkler system can designed by a fire engineer. The full means of escape and fire safety requirements are covered in detail later in this guidance

10 10.0 General technical & practical guidance for loft conversions A1: Preparation, protection, access & demolition Provide all necessary scaffolding, access ladders, material hoists, temporary protection and working platforms etc for the loft conversion which are to be erected, maintained, certificated, dismantled and removed by suitably qualified and insured specialists. All plumbing, drainage, heating, electrical services etc including re-siting of heating appliances/ boilers/ flues /tanks etc to be altered /modified /adjusted as necessary by suitably qualified & experience specialists or registered competent persons, tested & appropriate certification issued where required in this specification. Any asbestos is to be inspected by a specialist, removed and disposed off site by a specialistlicensed contractor in compliance with the Control of Asbestos Regulations Prior to and during works, the person carrying out the works is to liaise with and meet the requirements of the relevant Service Authorities, including the location and protection of all services as necessary. The builder is to allow for and maintain all temporary protection to the building to maintain weather tightness until completion of the works. All structural timber is to be grade C24, stress graded to BS 4978 and sawn to BS All timber is to be protected on site to minimize moisture content which must not exceed 22%. A2: Inspection of the existing roof & structure Existing foundations, lintels and wall structure that will be built off or support the new storey loads from the proposed works may need to be exposed at the discretion of the Building Control Surveyor and structural engineer to ensure that they are adequate and suitable - this may include opening up or excavating walls/floors (and making good to match the existing) to check internal foundations or walls. If they do not appear to be adequate to support the proposed works, details/justification of the proposed remedial works/alterations including necessary engineering calculations and details will need to be submitted for approval before works commence on site. A3: Alteration, modification & strengthening of the existing roof & structure Over haul existing roof coverings and structural timbers as necessary, replace defective and missing tiles, treated timber battens, roofing felt, lead valleys, flashings, facia boards, soffit/ barge boards and rainwater goods etc as necessary to match existing. Repoint/ rebuild defective masonry walls/ chimneys etc as necessary. Repair/ replace defective roof timbers as necessary. Existing timbers to inspected, repaired, replaced and treated as necessary by a specialist with a warrant backed guarantee against insect & fungal attack. Alteration/modification/strengthening of the existing roof structure/structural members/ walls etc should only be carried out/repaired/ replaced/ supported or removed in strict compliance with details and calculations received from a suitably qualified person. These details must be approved by building control before works commence on site. Trussed rafter roofs constructed using a series of complex trusses should only be altered, modified and converted in compliance with details and calculations carried out by a suitable qualified and experience property professional. No trussed rafter should ever be cut or modified in any way until a new supporting structure is in place which has been designed by a suitably qualified and experienced specialist designer. Further information for loft conversions with trussed rafter roofs can be obtained from TRADA at:

11 Diagram 1: Typical plan layout of a loft conversion with dormer pitched roof (not to scale) Internal sound insulated stud partition as guidance details Load bearing stud with thermal insulation as detailed below Existing walls with a threshold U value worse than 0.7, upgrade U value to 0.55 for cavity walls & 0.3 for solid walls as follows: 13mm vapour checked plaster board & skim 75 x 50mm timber studs at 400mm ctrs fixed to wall Thermal insulation fixed between studs as guidance details Proposed dormer roof omitted for clarity of layout FD 20 fire door 13mm vapour checked plaster board & skim 75 x 50mm timber studs at 400mm ctrs fixed to wall Insulation fixed between studs as guidance details Smoke alarm 30 minutes fire resisting (& sound insulating) stud partition to protect stairs as guidance details Stairs & handrail as guidance details EXISTING SEPARATING WALL Upgrade sound insulation to separating walls between dwellings as necessary as guidance details ADJOINING UNHEATED ROOF SPACE 13mm vapour checked plaster board & skim 12mm structural plywood skin & fixings to s/engineers details & calculations 100mm timber studs at 400mm ctrs Thermal insulation fixed between studs as guidance details Load bearing studs supported by structural beams to s/engineers details & calculations

12 Diagram 2: Typical section through a loft conversion with dormer pitched roof (not to scale) Roof insulation -see options in guidance notes 13mm vapour checked plaster board with skim finish Roof insulation & ventilation as detailed on other roof pitch 12mm plywood gusset screwed High level roof vents equal to a continuous 5mm air gap with fly screen if not breathable type felt If existing rafter undersized fix additional rafters alongside existing -birds mouthed over & fixed to structural stud joist hanger Structural stud partition as s/engineers details, insulated as detailed in guidance notes, with 13mm v.c.plaster board and skim finish Structural beam to s/engineers details & calculations Existing roof coverings Trimming joists & rafters to s/engineers details & calculations Ceiling joists- see guidance notes for sizes Roof insulation -see options in guidance notes Lay 150mm fiberglass insulation between joist and additional 170mm accross joists or other approved (U value 0.16). Ensure 50mm clear air space to underside of non breathable felts at eaves junction Dormer roof constructed as typical roof section detail and supported on timber wall construction with finishes to match existing or as stated in planning permission. See guidance noted for construction details. Trimming joists and rafters supporting dormer roofs to s/engineers details and calculations. Double glazed window and means of escape openings as detailed in guidance notes Code 5 lead flashings High level roof vents as main roof Ceilings to achieve 30 minutes fire resistance from under side Eaves ventilation required equal to a continuous 25mm air gap with fly screens both sides of roof if not breathable type felt Floor joist sizes - see guidance notes for sizes suitable for spans and spacing for noggins Sound insulation - see guidance notes 22mm thick moisture resistant t & g floor boards Note: see guidance notes for fire safety requirements, stairways /guarding details & checking exisitng foundations & lintels to support new storey loadings. Eaves ventilation required equal to a continuous 25mm air gap with fly screens both sides of roof if not breathable type felt Diagram 3: Typical section through a loft conversion with dormer flat roof (not to scale) NOTE: Alterations to existing roof structure including removal of structural members etc must be in compliance with structural engineers details & calculations which must be approved by building control before works commence on site. Bitumen bedded stone chippings covering the whole roof surface to a depth of 13mm To achieve a class AA designation in close proximity of boundary for spread of flame Treated flat roof joists fixed to beam with heavy duty galvanized hangers, fixed to treated wall plates bolted to web of beam. Flat roof joist sizes and spacing to suit clear spans as guidance notes Strip back & refix roof coverings with new roofing felt & treated battens as necessary, dress flat roof membrane over plywood & tiling fillet (150mm min above flat roof) to provide water proof junction. Provide temporary protection & support as guidance notes Suggested ridge detail- steel ridge beam supported on pad stones into load bearing walls/intermediate load bearing columns, with 50mm deep treated timber plate bolted to top of beam, rafters birds mouthed over plate and mechanically fixed. High level roof vents equal to a continuous 5mm air gap with fly screen if not breathable type felt increase to 25mm to cross flat roof (excludes warm roofs) If existing rafter undersized fix additional rafters alongside existing -birds mouthed over & fixed to structural stud Roof insulation -see options in guidance notes 13mm vapour checked plaster board with skim finish Lay fiberglass insulation between joists and additional layer across joists (or other approved) as guidance details. Ensure 50mm clear air space to underside of non breathable felts at eaves junction Ceiling joists-see guidance notes for sizes Structural stud partitions as s/engineers details, insulated as detailed in guidance notes, with 13mm v.c.plaster board and skim finish Structural beams to s/engineers details & calculations NEW FLAT ROOF Single ply polymeric or three ply built up felt roofing in bitumen water proof coverings applied by flat roofing specialist as spec. 22mm external quality plywood decking or other approved Treated timber firing strips cut to 1:60 min gradient- laid with falls to gutter (allow 50mm min air gap in depth of firing strip from u/side of deck to top of insulation 50mm min air gap Insulation fitted below roof deck (cold roof & will require cross ventilation as detailed) or insulation fixed above deck (warm roof and will not require any ventilation). See guidance notes for flat roof insulation options 13mm plasterboard with foil backing or 500g polythene to provide a vapour check 50mm welted drip on galvanized plate to centre line of gutter fixed to 75mm deep timber nosing piece Matching Upvc gutters, facia/barge board with 25mm continuous air gap with insect screen Timber lintel to s/engineers details & calculations Matching double glazed window fitted with means of esape openings in bedrooms (or inner rooms) see guidance noted for details Matching painted render on stainless steel lath with drained cavity or vertical tile cladding on insulated stud walls - see guidance notes for details Code 5 lead flashings (and soakers to tile/roof junction) Proprietary high level roof vents equal to a continuos 5mm air gap fitted with insect screen Roof insulation and eaves ventilation as detailed on other roof pitch joist hanger Ceilings to achieve 30 minutes fire resistance from under side Eaves ventilation required equal to a continuous 25mm air gap with fly screens both sides of roof if not breathable type felt Floor joist sizes - see guidance notes for sizes suitable for spans and spacing for noggins Sound insulation - see guidance notes 22mm thick moisture resistant t & g floor boards Note: see guidance notes for fire safety requirements, stairways /guarding details & checking exisitng foundations & lintels to support new storey loadings. NOTE: Alterations to existing roof structure including removal of structural members etc must be in compliance with structural engineers details and calculations which must be approved by building control before works commence on site

13 A4: New pitched roofs Pitched roof coverings Roof covering to consist of matching slate or tile and associated capping, verge/eaves details fixed in accordance with manufacturer s details for pitch and exposure as detailed on the drawings. Cladding to be fixed to a minimum 25 x 50mm treated timber batten or to manufacturer s directions and roof timbers to be overlaid with un-tear able breathable/non breathable roof felt underlay to BS 747 or relevant BBA certificate. Roof to be formed from kiln-dried stress graded timbers sized, spacing, spans, bracing and fixings as detailed on the drawing or tables below. Alternatively, the roof may be formed from proprietary prefabricated manufactured trusses/attic trusses and bracing to BS 5268 but both with a foil backed 12.5mm plasterboard and skim ceiling finish. Pitched roof structure Roof to be constructed using either manufactured roof trusses or a cut roof as follows: Roof trusses (including attic & girder trusses) Roof to be constructed using specialist designed and manufactured trusses (or Attic trusses where forming room in the 600ctrs (max) to BS 5268: A2 94. Trusses to be fixed and braced strictly in accordance with manufacturers details and mechanically fixed to 100 x 50mm sw treated wall plates via galvanized steel truss clips. Reinforced concrete pad stoned required to support girder trusses to details and calculations by a suitably qualified person. The person carry out the building work is to check and confirm the actual roof pitch to the truss manufacturer prior to placing an order. Details of trusses to be prepared by specialist designer/manufacturer, submitted and approved by building control prior to commencing roof construction. Cut roof construction Roof to be constructed using kiln dried stress graded timber. Rafters, ceiling joists, purlin, hanger and binder sizes as stated on tables below or see TRADA Span Tables- suitable for the proposed clear spans and all properly fixed together using approved fixings. Where the ceiling joists are raised above wall plate level they must be fixed within the bottom third of the rafter using 12mm diameter high tensile bolts and steel toothed connectors to connect each rafter and ceiling joist to prevent possible roof spread. Joists raised above this level are to be designed by a suitably qualified person and approved by building control before works commence. Struts & braces to be 100 X 50mm, hips to be splayed rafter depth + 25mm (under 30 degree pitch the hips are to be designed by a suitably qualified person), lay-boards to be the splayed rafter depth + 25mm X 32mm thick, ridges to be splayed rafter depth + 25mm, all valleys beams are to be designed by a suitably qualified person, wall plates to be 100 x 50 fixed to inner skin of cavity wall using galvanized strapping as detailed below. Hip rafters to have 100 X 75mm angle ties connected across wall plates in housed joints at corners of roof & hip irons screwed to hip rafters. Soffits, fascias and barge boards etc to match the existing or in UPVC to BS 4576, fixed in compliance with manufacturers details. Allow for all necessary alteration/modification of any existing adjoining roof as required to enable the proper completion of the works and in agreement with building control

14 Allow for building in as work proceeds or insertion of proprietary stepped/cavity tray dpc to follow line of new roof 150mm above all roof/wall abutments as necessary using code 5 lead flashings. Tie the new roof into the existing, alter/modify/renew existing roof coverings and form a weather tight structure. Fix 12.5mm foil backed plasterboard (joints staggered) and 5mm skim coat of finishing plaster to the underside of all ceilings using galvanized plasterboard nails. Roof pitch to (single storey) single skin buildings with walls 100mm thick should not exceed 40 degrees without structural engineers details & calculations to confirm stability of the structure. Cut roofs over 40 are to be braced to BS Table 1: Spans for Common Domestic Timber Rafter Sizes at 400mm spacing (Strength Class C24) Slope of Roof (degrees) Size of Rafter Maximum clear span (m) Breadth X Depth (mm) Table 2: Spans for Common Domestic Timber Ceiling Joist Sizes at 400mm spacing (Strength Class C24) Size of Ceiling Joist Maximum clear span (m) Breadth X Depth (mm) Table 3: Spans for Common Domestic Timber Purlin Sizes (Strength Class C24) Slope of Roof (degrees) Size of Purlin Breadth X Depth (mm) Spacing of Purlins (mm) Maximum clear span (m)

15 Table 4: Permissible Clear Spans for Common Ceiling Binders Sizes (Strength Class C24) Size of Binder Breadth X Depth (mm) Maximum clear span (m) Spacing of Binders (mm) Diagram 4: Typical section through a pitched roof (not to scale) Roof slates/tiles to match existing or as stated in planning permission fixed as manufacturers details and suitable for the pitch Breathable or non breathable roofing felt fixed as manufacturers details 25 x 50mm treated battens at a guage to suit coverings Rafters (see construction details and table in specification for sizes of rafters suitable for clear spans) Ceiling joists (see construction details and table in specification for ceiling joist sizes suitable for clear spans Rain water gutter Facia/soffit boards Eaves ventilation equal to a continuous 10mm air gap with insect screen (may not be required with certain breathable roof membranes) Wall plates (strapped at 2.0m ctrs) Continuous insulation Sound insulated stud partition as detailed in specification NOTE: Proprietary high level roof vents to be installed where insulation follows slope of roof- equal to a continuous 5mm air gap with insect screen Ridge tiles to match roof coverings Ridge board (see specification for details) Hangers to support hangers if additional support is required to ceiling joists (contact building control for details) Binders to support ceiling joists if they require additional support (contact building control for details) Roof insulation (see options in specification Galvanized steel strapping at 2m ctrs built into cavity and fixed over 3 rafters with noggins as detailed in specification Vapour checked plaster board Double glazed window bedrooms/ inner rooms to be fitted with openings suitable for escape as detailed in the specification Proprietary insulated steel lintels suitable for spans and loadings in compliance with lintel manufactures standard tables Roof restraint Roof and walls to be provided with lateral restraint straps across at least 3 timbers as noted in wall section at ceiling, wall plate and verge levels with 30 x 5mm x 1m galvanized metal straps or other approved to BSEN at maximum 2m centers

16 Roof insulation Insulation to be fixed to manufactures details and must be continuous with the wall insulation but stopped back at eaves or at junctions with rafters to allow a 50mm air gap in ventilated cold roofs. Table 5: Insulation laid horizontally between and over ceiling joists (Vented cold roof achieving a U-value of 0.16 W/m².k) Product K -Value Position in roof Crown Wool & Rock-wool Roll mm between joists & 150mm laid across joists Alternatives TBA Table 6: Insulation fixed between/under rafters (Vented cold roof achieving a U-value of 0.18 W/m².k) Product K -Value Position in roof Kingspan Kooltherm K mm friction fixed between rafters & 42.5mm fixed under rafters* Or other approved with a K value of Alternatives TBA * Where rafters are only 100mm deep, battens should be provided to their underside to maintain a 50mm air gap above the insulation where a non breathable roofing felt is used or battened to allow a 25mm sag in felt if using a breathable roofing membrane as the manufacturers details. Table 7: Insulation fixed between/over rafters (Warm roof achieving a U-value of 0.18 W/m².k) Product K -Value Position in roof Kingspan Kooltherm K mm fixed between rafters & 55mm fixed over rafters Or other approved with a K value of Alternatives TBA 25 x 50mm counter battens to be fixed over insulation to allow for sag in breathable roofing membrane as manufacturers details

17 Diagram 5: Typical roof valley detail (not to scale) 200mm min Roof coverings & roof structure as specification & section details 125mm min Rafter birds mouthed over 150 x 50mm wall plate (wall plated strapped at 2.0m ctrs Pcc pad stone or dense blockwork Breathable roofing membrane lapped over lead & forming drip Tiling fillet Code 5 lead lined gutter- lead sizes, drips & welted joints etc to the Lead Development association details 25mm treated gutter board fixed to: 50 x 50mm treated timber gutter bearer Diagram 6: Typical section through a dormer roof (not to scale) Roof slates/tiles to match existing or as stated in planning permission fixed as manufacturers details and suitable for the pitch 25 x 50mm treated battens at a guage to suit coverings Breathable or non breathable roofing felt fixed as manufacturers details Ridge board as specification Rafters (see construction details and table in specification for sizes of rafters suitable for clear spans) Trimming joists as spec Rain water gutter, facia/soffit boards etc as spec Eaves ventilation equal to a continuous 10mm air gap with insect screen (may not be required with certain breathable roof membranes) 13mm vapour checked plaster board & skim Ceiling joists (see construction details and table in specification for ceiling joist sizes suitable for clear spans Insulation deatils as tables in specification Dormer walls constructed with painted renders or cladding on insulated timber frame as spec details Code 5 lead flashing & valleys Dormer roof supported on rafters doubled up & bolted together See main roof for construction details

18 Roof ventilation Roof insulation to be continuous with the wall insulation but stopped back at eaves or at junctions with rafters to allow a 50mm air gap. Cross ventilation to be provided by a proprietary eaves ventilation strip equivalent to a 25mm continuous gap at eaves level with insect grill. Alternatively, where cross ventilation is not possible such as mono pitch, coved ceiling or room in the roof provide additional ridge/high level ventilation equivalent to a 5mm gap in the form of proprietary vent tiles spaced in accordance with manufacturer s details. Ventilation to the roof space may be omitted, only if a proprietary BBA or similar approved breathable roof membrane, with minimum 25mm thick treated vertical counter battens and proprietary eaves carrier system is used. Breathable roof membranes & proprietary roof vents must always be installed as manufacturers details (note: some breathable membranes may also require additional roof ventilation) A5: Flat roof construction Flat roof to be carried out as detailed on the drawings. Moisture content of timber should not exceed 20% and to be kiln dried & grade C24. Workmanship to comply to BS 8000:4. All fixings to be proprietary stainless steel or galvanized steel. Waterproof coverings: to be either: 3 layers of high performance felt (hot bonded together with bitumen) to a current BBA Certificate in compliance with BS8217 Single layer system with a current BBA or WIMLAS Certificate Glass reinforced plastic (GRP) system with a current BBA or other approved accreditation Lead sheet fixed in compliance with the Lead Development Associations guide to good practice or in compliance with the Lead Sheet Associations technical guidance sheets available from: Mastic asphalt fixed in compliance with the Mastic Asphalt Councils technical guides & specifications Waterproof covering to be laid in compliance with manufacturers details by flat roofing specialist onto separating layer over roof insulation layer in compliance with Table 14 below to form a warm roof (or alternatively insulation fixed between/under joists in compliance with Table 13 below forming a cold roof ) fixed to, 22mm external quality plywood decking or similar approved laid to 1:60/80 minimum gradient using firing strips at spacing to match joists, fixed onto timber flat roof joists constructed of kiln dried structural grade timber with sizes and spacing suitable for the proposed clear span as annotated on the drawing or in compliance with Table 9 below. Surface finish to flat roofs: to consist of bitumen bedded stone chippings covering the whole surface to a depth of 12.5mm to achieve a class AA, AB or AC fire rated designation for surface spread of flame. Restrain flat roof to external walls by the provision of 30 x 5 x 1000mm lateral restraint straps at maximum 2000mm centers fixed to 100 x 50mm wall plates and internal wall faces Flat roof insulation to be in compliance with tables 13 & 14 below. Flat roof insulation is to be continuous with the wall insulation but stopped back to allow a continuous 50mm air gap above the insulation in ventilated cold decks. Cross ventilation to be provided on opposing sides by a proprietary eaves ventilation strip equivalent to a 25mm continuous gap at eaves level with insect grill. Note: Warm roof applications ie insulation above the structural deck do not require ventilation

19 The design, workmanship & selection of materials should comply with Model Specification Sheet P.L.1 Built-Up Roofing: Plywood Deck, published by The British Flat Roofing Council. Metallic roof trims to be of non-corrodible material & resistant to sunlight & not fixed through the water proof covering. All timber to be treated using CCA vacuum/pressure or O/S double vacuum to BS 5268:5, including all cut ends of timber etc 300mm of any joint. All flat roofing works to be carried out by a specialist flat roofing contractor and all materials etc to be fitted in compliance with manufacturer s details. Work should not be carried out during wet weather or when the deck has not fully dried out. A 500g vapour control barrier is required on the underside of the roof below the insulation level. Fix 12.5mm foil backed plasterboard (joints staggered) and 5mm skim coat of finishing plaster to the underside of all ceilings using galvanized plasterboard nails. Diagram 7: Typical section through a flat (cold) roof (not to scale) 13mm diam stone chippings bedded in hot bitumen Water proof coverings applied by flat roofing specialist as spec. External quality structural decking Firing strips at 1:60 min gradient 50mm min air gap Insulation to achieve a min U value of 0.2, fixed above or below structural decking as above tables 1:60/80 gradient Plasterboard with vapour check Welted drip 25mm continuous air gap with insect screen wall plate & strapping as spec details Cavity wall as spec details Flat roof joist sizes and spacing as spec tables Proprietary steel box beam as manf details suitable for clear span or timber lintel to s/engineers details & calculations to suit clear spans of openings Note: if insulation is fixed above the structural deck (forming a warm roof) the above ventilation details can be omitted Welted drip Rain water gutters, facia/ barge board 25mm continuous air gap with insect screen Table 8: Spans for Common Flat Roof Joist Sizes (Strength Class C24) Access for maintenance and repairs only Size of joist Breadth X Depth Spacing of joist (mm) (mm) Maximum clear span (m)

20 Table 9: Insulation Fixed Between/Under Flat Roof Joists (Vented cold roof achieving a U-value of 0.18 W/m².k) Product K -Value Position in roof Kingspan K7 Kingspan K18 Or other approved with a K value of mm between joists (2 x 70mm) 32.5mm fixed under joists Note: The joist depth must be sufficient to maintain a 50mm air gap above the insulation and cross ventilation to be provided on opposing sides by a proprietary ventilation strip equivalent to a 25mm continuous gap at eaves level with insect grill for ventilation of the roof space. Table 10: Insulation Fixed above Flat Roof Joists (Non vented warm roof achieving a U-value of 0.18 W/m².k) Product K -Value Insulation fixed above deck Kingspan Thermaroof mm fixed above deck in a single layer Or other approved with a K value of Alternatives TBA Valleys and lead work Lead work, flashing, soakers, valleys and gutters, etc, to be formed from Code 5 lead sheet and fully supported on treated valley boards, etc, and to have a minimum 150mm lap joints, dressed 200mm under tiles, etc, and not to be fixed in lengths exceeding 1.5m and to be fixed in accordance with the roof cladding manufacturers and the Lead Development Association recommendations. Lofts hatches, doors & Light wells to roof spaces All hatches, doors and light wells in the roof space to be insulated to the same standard as the roof, draft stripped and positively fixed

21 A6: New external walls Cavity walls (U-value 0.28 W/m².k - area weighted average value) Walls to consist of either approved reconstituted stone facings,100mm tooled flush jointed brickwork or 2 coat rendered 100mm dense concrete blockwork external skin dependant upon exposure with a 100mm thick lightweight high performance 2.8N/mm² insulation block with either a 13mm lightweight plaster finish or 12.5mm plasterboard skimmed dry lining. Where required external natural stone facings to be tied to external block work with wall ties as detailed below and foundation widths increased by 150mm. Walls to be built with 1:5/6 cement mortar and tied with BBA approved stainless steel wall ties suitable for cavity width at maximum spacing of 750mm horizontal (increased to 600mm if retaining partial fill insulation using proprietary retaining rings as manufacturers details), 450mm vertical and 225mm at reveals, verges and closings for cavities up to 100mm wide. Cavity width and insulation details to be constructed as Table below to achieve a U- value of not more than 0.28 W/m².k. Wall insulation to be continuous with roof insulation level and taken below floor insulation levels as manufacturer s details. Table11: Insulation requirements for external cavity walls with 100mm dense Brick or rendered block external skin & internal plaster/dry lining plaster finish Clear cavity width required Insulation type & Minimum thickness Overall cavity width required Internal Block Type & Thickness Partial cavity fill 50mm 90mm 50mm Alternatives TBA Full fill n/a Alternatives TBA 40 mm Kingspan Kooltherm K8 or Other approved with K value of mm Kingspan Kooltherm K8 or Other approved with K value of mm full fill glass fiber (K value 0.037) Suitable for full fill 100mm n/a 100 mm insulation block (k value 0.15 or lower) 100 mm dense concrete block (K value 1.13) 100 mm insulation block (k value 0.15 or lower)

22 External timber framed walls with render finish (U-value 0.28 W/m².k - area weighted average value) Render finish (to comply to BS 5262) - to match existing or as specified to be applied in 3 coats at least 16mm 20mm thick overall to render lath. First & second coats 1:3 (cement : sand with plasticizer). final coat 1:6 (cement : sand with plasticizer)- proportions by volume. Render should be finished onto an approved durable render stop, angle beads or jointing sections- stainless steel or other approved using drilled or shot fired fixings only. Stainless steel render lath fixed (using stainless steel staples) to vertical studs at 600mm max ctrs. laps wired together at 150mm ctrs. (Mesh to be backed by a water resistant membrane) & fixed to: treated battens - 25 x 50mm preservative treated battens fixed vertically to studs at max 600mm ctrs using 75mm long hot dipped galv or stainless steel annular ring nails, fixed to: Breathable membrane- Tyveck or similar approved suitable for timber framed walls to current BBA certification, fixed to: External quality plywood- 12mm thick marine ply wood (or other approved) fixed to: Treated timber frame constructed using: 100/150mm x 50mm head & sole plates and vertical studs at 400mm ctrs, to s/engineers details & calculations. Thermal insulation board in compliance with table below to be tightly friction fixed between studs with 13mm vapour checked plaster board fixed to internal face of studs and finished with 3mm skim coat of finishing plaster. All junctions to have water tight construction & seal all perimeter joints with tape internally and with silicon sealant externally. Diagram 8: Typical section through external timber framed walls with painted render finish (not to scale) Masonry paint finish 16-20mm thick render finish Stainless steel render lath with water resistant membrane to stop render filling cavity 25 x 38mm treated timber battens at 600mm ctrs fixed vertically to form drained cavirty TYVEK or similar breathable membrane 100 x 50mm treated stud at 400mm ctrs Thermal insulation as guidance details 13mm vapour checked plaster board & skim finish 100 x 50mm soleplates fixed to base 12mm external quality plywood or other approved Stainless steel stop bead forming drip Insect proof mesh (non rust) Construction details as guidance External timber framed walls with cladding finish (U-value 0.28W/m².k - area weighted average value) Approved timber/upvc weatherboarding/vertical wall tiling fixed with proprietary rust resistant fixings to: 50 X 25mm treated battens/counter battens at 400mm ctrs fixed to: Tyvek vapour permeable membrane suitable for timber framed walls & fixed as manufacturers details to: 12mm WPB ext quality plywood sheathing (joints covered by dpc/battens) fixed to 100 X 50mm timber studs at 400mm ctrs with 100 X 50mm timber head & sole plates & 2 rows noggins and diagonal bracing as S/Engineers details. Studs exceeding 2.5m high to be designed by Structural Engineer. Thermal insulation board in compliance with table below to be tightly friction fixed between studs with 13mm vapour checked plaster board fixed to internal face of studs and finished with 3mm skim coat of finishing plaster. All junctions to have water tight construction & seal all perimeter joints with tape internally and with silicon sealant externally

23 Diagram 9: Typical section through external timber framed walls with cladding finish (not to scale) Upvc weatherboarding/vertical wall tiling fixed with proprietary rust resistant fixings 25 x 38mm treated timber battens at 600mm ctrs fixed vertically to form drained cavirty TYVEK or similar breathable membrane 12mm external quality plywood or other approved Cladding stop fillet & insect proof mesh 100 x 50mm treated stud at 400mm ctrs Thermal insulation as guidance details 13mm vapour checked plaster board & skim finish 100 x 50mm soleplates fixed to base Construction details as guidance Wall abutments Vertical junctions of new and old walls to be secured with proprietary profiled stainless steel metal crocodile type system with a continuous cavity fixed with DPC and pointed with flexible mastic as manufacturer s details. Lintels & weep holes Proprietary manufactured lintels to current British Standards/Euro codes (including specialist lintels supporting stone facings) are to be provided over all structural openings. The positions, types, sizes, end bearings etc of lintels must be in compliance with the lintel manufacturers standard tables suitable for the proposed loadings and clear spans. Stop end and dpc trays to be provided above all externally located lintels in compliance with lintel manufacturer s details. Weep holes at 450mm centers with at least two per opening. Structural columns/beams etc Non proprietary beams/columns including pad stone to be fabricated and installed in compliance with details and structural calculations carried out by a suitably qualified and experienced person, which must be approved by building control before works commence on site. Dpc trays to be provided above all externally located beams. Weep holes at 450mm centers with at least two per opening. Expansion joints External walls should be provided with adequately spaced and sized expansion joints, in accordance with masonry manufactures details with adequate tying to each side of the joint and leaf of masonry using stainless steel wall ties (normally at each block height) and sealed externally with a proprietary flexible mastic sealant. (Normally expansion joints are 10-12mm wide and spaced vertically at max 12m ctrs in brick work & 6m ctrs in block work) Strapping and restraint Walls to be restrained at intermediate floor, ceiling and gable walls by the provision of 30 x 5 x 1000mm lateral restraint straps or other approved in compliance with BS EN 845-1, at maximum 2m centers carried across at least 3 joists or rafters, etc, with a minimum of 38mm wide x ¾ depth noggins. Cavity Closers Proprietary acoustic/insulated fire stop cavity closers, or similar are to be provided to all cavity openings/closings, tops of walls and junctions with other properties

24 A7: Internal load bearing walls Internal load bearing timber stud walls Load bearing timber stud walls to be in compliance with details and calculations by a suitably qualified and experienced person, which must be approved by building control before works commence on site. Typically load bearing stud walls not exceeding 2.5m high are to be constructed of 100 x 50mm C24 soft wood studs fixed vertically at 400mm ctrs with head and sole plates and intermediate noggins fixed at 600mm, with thermal insulation friction fixed air tight between studs as detailed in table below, with 12mm thick structural plywood glued & screwed to the full height & width of the room side face of the stud wall and finished with 15 mm plasterboard and skim. Insulated & draught proofed access hatches to be formed between studs. New rafters to be birds mouthed over and mechanically fixed to head plate, and mechanically fixed to existing rafters by an approved method. Diagram 10: Typical section through internal load bearing timber stud wall supporting roof loads (not to scale) New rafter fixed alongside existing, birds mouthed over & mechanically fixed over new stud 100 x 50mm timber head plate 100 x 50 vertical timber studs at 400mm ctrs Thermal insulation friction fixed tightly between studs 12mm structural plywood glued & screwed to studs 15mm vapour checked plaster board & skim 100 x 50 timber sole plate New structural beam supporting load bearing stud to s/engineers details & calculations Table 12 : Insulation requirements to exposed timber framed walls (U-value 0.28 W/m².k) Insulation Type Minimum Thickness mm Kingspan Kooltherm K12 or other 90 mm approved with a K value of Alternatives TBA Internal load bearing masonry partitions Internal load bearing walls to be minimum100mm thick 7N/mm2 dense concrete blocks (actual wall thickness must not be less than the wall it supports above), built off suitable foundations with pre-cast concrete/proprietary steel lintels over openings (in compliance with lintel manufacturers span tables) and walls bonded/tied to external or party walls with proprietary ties each course and restrained by floor or ceiling joists/trusses

25 A8: Internal non load bearing partitions Internal masonry non-load bearing partitions Internal non-load bearing partitions to be constructed of 100mm 2.8/mm² dense concrete blocks built off a thickened floor slab and tied/block bonded to all internal and external walls at maximum 225mm centers with either a plaster or dry lined finish as the external walls. Internal timber studwork non-load bearing partitions Non-load bearing stud partitions are to be constructed of 100 x 50mm soft wood studs, fixed vertically at 400mm ctrs with head and sole plates and intermediate noggins fixed at 600mm with a minimum of 25 mm of 10Kg/m² proprietary sound insulation quilt suspended in the stud and finished with 15 mm plasterboard and skim both sides

26 A9: Upgrading existing external walls Where existing external walls are to be used as part of the loft conversion and have a threshold U-value worse than 0.7, the U-values should be upgraded to 0.55 for cavity walls & 0.3 for solid walls. Upgrade walls typically using 75 x 50mm soft wood studs at 400mm ctrs fixed vertically to existing walls with mechanical fixings (with a strip of damp proof course between stud & wall if there is a risk of moisture penetration), thermal insulation to be friction fixed air tight between studs as detailed in table below and 15 mm vapour checked plasterboard fixed to studs with plaster skim finish. Existing solid external walls less than 328mm thick in rendered stone or brick or less than 250mm thick in rendered blockwork, should be tanked internally with a BBA or other approved tanking system to prevent the ingress of moisture into the building. Diagram 11: Typical plan layout of upgrading existing walls in loft conversion (not to scale) Existing walls with a threshold U value worse than 0.7, upgrade U value to 0.55 for cavity walls & 0.3 for solid walls as follows: 13mm vapour checked plaster board & skim 75 x 50mm timber studs at 400mm ctrs fixed to dpc strip & existing wall Thermal insulation fixed between studs as guidance details Solid external walls less than 328mm thick rendered stone/brick or less than 250mm thick rendered blockwork to be tanked internally with a BBA approved water proof tanking system to prevent ingress of moisture into the building Table 13: Insulation requirements for upgrading existing external walls External wall type Insulation Type Minimum Cavity walls with threshold U- value worse than 0.7, upgrade U- value to 0.55 Solid walls with threshold U-value worse than 0.7, upgrade U-value to 0.30 Kingspan Kooltherm K12 or other approved with a K value of Kingspan Kooltherm K12 or other approved with a K value of Thickness mm 60 mm 70mm

27 A10: Separating (party) walls & floors between dwellings ( Also see relevant sections in ADE) Masonry party walls separating dwellings (U-value 0.2 W/m 2.K) Party walls to be constructed of 2 skins of plastered 100mm dense concrete block with a clear 50mm cavity and BBA approved wall ties spaced as external walls up to the underside of the roof and fire stopped with mineral wool or an approved proprietary intumescent product to achieve a minimum 45dB value for airborne sound insulation. The party wall is to be bonded/tied to the inner leaf and the junction of cavities are to be fire stopped throughout its length with a proprietary acoustic/ insulated fire stop cavity closer and all other vertical and horizontal cavities are to be closed in a similar manner to provide effective edge sealing and a U-value of 0.2 W/m 2.K. Timber frame party walls separating buildings (U-value 0.2 W/m 2.K) Timber framed stud walls to achieve a minimum 45 db value for airborne sound insulation and constructed with 100 x 50mm sawn timber studs at 400mm ctrs with head & sole plates, with 2x 50mm thick layers ROCKWOOL RWA 45 mineral wool friction fixed between studs, and 2x 15mm thick layers of LAFARGE db check wall board fixed both sides of stud (joints staggered) with skim coat of plaster finish- as wall board manufacturers details. No electrical fittings to be fixed into/onto party walls & all gaps to be fire sealed & smoke stopped to the full height and width of the party wall and upto the underside of the roof coverings using mineral wool (not glass wool) or an approved proprietary intumescent product to provide effective edge sealing and a U-value of 0.2 W/m 2.K. Upgrading sound insulation of existing separating walls Existing wall should be at least 100mm thick, of masonry construction and plastered on both faces. With other types of existing wall the independent panels should be built on both sides. Construct new independent frame fixed at least 10mm from one side of the existing wall using either; 100 x 50mm timber studs at 400mm ctrs fixed onto head & sole plates or to a proprietary galvanised metal frame, fixed as manufacturers details. Fix 50mm thick ROCKWOOL RWA 45 sound insulation or other approved (min density 16kg/m3) friction fixed between studs Fix two layers of 15mm thick db checked wall board with staggered joint and plaster skim finish to the independent frame using mechanical fixings. Note- allow a minimum distance of 35mm between face of existing wall & inner wall board face. No electrical fittings to be fixed into/onto party walls & all gaps to be fire sealed & smoke stopped to the full height and width of the party wall and upto the underside of the roof coverings using mineral wool (not glass wool) or an approved proprietary intumescent product to provide effective edge sealing and a U-value of 0.2 W/m 2.K. Party floors separating buildings Outside the scope of this guidance- see relevant sections in ADE Sound testing requirements Pre completion sound testing is required for all new/upgraded party walls/floors which must be carried out by a suitably qualified person or specialist to demonstrate compliance with Approved Document E and copy of test results sent to building control

28 A11: Additional provisions for 3 storey buildings/extensions Compressive strength of masonry units The compressive strength of bricks and blocks used in three storey construction is as follows: (i) Outer leaf of cavity wall Blocks & bricks to be 7N/mm2 from foundation level upto the underside of the structural roof. (ii) Inner leaf of cavity wall Blocks to be 7N/mm2 from foundation level upto the underside of the first floor level. Blocks above this level upto the underside of the structural roof to be 2.8N/mm2. (iii) Internal walls Blocks to be 7N/mm2 and 140mm thick upto the underside of the first floor level. Blocks above this level upto the underside of the structural roof to be 2.8N/mm2. A12: Intermediate upper floor(s) Floor to be constructed of kiln dried structural grade timber joists with sizes and spacing suitable for the proposed clear span as annotated on the drawing or in compliance with the tables below. Joists to be supported by heavy-duty proprietary galvanized metal restraint joist hangers built into walls or fixed to treated timber wall plates (same sizes as joists) resin bolted to walls at 600mm centers using approved 16mm diameter stainless steel fixings. Alternatively, joists can be built into walls using approved proprietary sealed joist caps. Joists are to be doubled up and bolted together for trimmers, under partitions and baths. Floor void between joists to be insulated with a minimum thickness of 100 mm of 10Kg/m³ proprietary sound insulation quilt, ceiling to be a minimum 15mm plasterboard and skim and floor joist covering to be a minimum of 20mm softwood tongue and groove softwood boards or moisture resistant particle/chipboard to give overall 30 minutes fire resistance. Floor joists to be provided with 1 row of 38 x ¾ depth solid strutting at ends between joist hangers or proprietary galvanized struts to BS EN fixed as manufacturers details, at mid span for m spans and 2 rows at ¹/3 points for spans over 4.5m. Diagram 12: Typical section through a loft floor (not to scale) 22mm thick moisture resistant t & g floor boards fixed to joists Floor joists fixed between existing joists. Joists sizes, spacing & noggins suitable for clear spans as guidance notes & tables 100mm thick sound insulation as guidance notes Steel beam to s/engineers details & calculations with 100 x 50mm timber plate bolted to top flange. (beam fixed above existing ceiling joists on pad stones) Ceilings to achieve 30 minutes fire resistance from under side Heavy duty galvanised hangers supporting floor joists. Hangers fixed to timber plate bolted into web of beam using 12mm high tensile bolts at 800mm ctrs

29 Diagram 13: Typical section through an upper floor (not to scale) Double glazed window bedrooms/ inner rooms to be fitted with openings suitable for escape as detailed in the specification 100mm minimum width insulation block (see options in specification) Wall grade insulation (see options in specification) 50mm clear cavity if using partial fill cavity wall insulation (see options in specification) Wall ties and spacings as detailed in specification Damp proof course and insulated closer Galvanized steel straps at 2m ctrs built into cavity and fixed over 3 joists with noggins Sound insulated stud partition 22mm t & g moisture resistant floor boarding Strutting between joist (see specification for spacings) Floor joists (see construction details and table in specification for sizes of joists suitable for clear spans) Sound insulation quilt as specification 100mm minimum width external wall in materials to match existing or as specified in planning permission Proprietary insulated steel lintels (with dpc trays and stop ends) suitable for clear spans and loadings in compliance with lintel manufactures standard tables Table 14: Spans for Common Domestic Floor Joist Sizes (Strength Class C24) Size of joist Breadth X Depth Spacing of joist (mm) (mm) (mm) Maximum clear span (m) Table 15: Spans for Common Trimmer Joist supporting Trimmed Joists (Strength Class C24) Length of trimmed joists (m) Size of trimmer (mm) Clear span of trimmer joist (m) supporting 2 x 47 x x 47 x x 47 x x 47 x x 75 x 220 trimmed joists Table 16: Spans for Common Trimming Joist supporting Trimmer Joist (Strength Class C24) Length of trimmer joist (m) max Size of trimming joist Clear span of trimming joist (m) supporting (mm) 2 x 47 x x 47 x x 47 x x 47 x x 75 x 220 Floor joists doubled up under partition walls & baths Sound insulated plaster board achieving 30 minutes fire resistance trimmer joist mm dense concrete partitions precast concrete/proprieteray steel lintols, sizes suitable for clear spans as manufactures standard tables

30 Sound insulation to floors within the dwelling Intermediate floors to be provided with sound insulation as described in the relevant floor section in this document. SVP pipe boxing SVP pipe boxing to consist of soft wood framing, 2 layers of 15mm plasterboard and skim and mineral wall sound insulation quilt. Boxing to be continuously carried up to roof space for soil and vent pipe and provided with air grills where an air admittance valve is used. Exposed intermediate upper floors Semi exposed intermediate timber floors over unheated areas such as garages, porches, walkways, and canopy s to be insulated with the following minimum thickness and types of insulations to achieve a U-value 0.22w/m².k as in Table 6 below. Where the construction is open to the environment a vapour barrier and proprietary external mineral fiber or similar 30 minute fire and moisture resistant boarding is to be applied to the underside of the floor. Table 17: Insulation requirements to exposed intermediate floors U-value 0.22 W/m².k Insulation Type Minimum Thickness Jablite Jabfloor mm Celotex & Kingspan 70 mm Polyfoam 100 mm Rockwool Rockfloor 120mm

31 Part B: Fire safety & means of escape Means of escape from single storey dwelling with new second storey The conversion of Bungalows or similar single storey building to form a new first floor do not require a protected hall, landing or fire doors, but the supporting floor must still be provided with 30 minute fire resisting construction. The stair may be positioned in a ground floor room such as living room, provided there is an external door that opens directly to the outside for means of escape. All rooms or bedrooms on the first floor (except bathrooms or toilets) must be directly accessible off the stair landing. Smoke detection must be installed as detailed below, with an additional interlinked heat detector at ceiling level in kitchens which are open to the stairs at ground level. Means of escape windows to be fitted with proprietary hinges to open to the minimum required clear width of 450mm. Escape windows must have minimum clear opening casement dimensions of 0.33m² and 450mm (typically 450mm wide x 750mm high), located within mm above floor level to all bedrooms and habitable rooms at 1st floor level and inner habitable rooms on the ground floor. Windows above the ground floor storey and within 800mm of floor level are to be provided with containment/ guarding/ proprietary catches which should be removable (child proof) in the event of a fire. Where escape windows cannot be achieved, direct access to a protected stairs (or protected route to inner rooms) is acceptable in compliance with the guidance sections below & ADB1- par 2.6 (a) or (b)

32 Means of escape from two storey dwellings with new third storey 4 options are available: Option 1: Protected stairway The new and existing stairs, landings and hallway from the new 3 rd storey down to the ground floor must be protected and enclosed in 30-minute fire resisting construction and the protected stairs must discharge directly to an external door as diagram below. 30 minutes fire resisting construction is required to the underside of the new upper storey floor. DINING KITCHEN BED 2 BED 3 ALL PARTITIONS ENCLOSING THE STAIRS IS TO HAVE 30 MINUTES FIRE RESISTANCE INCLUDING GLAZING* ENSUIT FD20 FD20 NEW BEDROOM FD20 SD UP ALL PARTITIONS ENCLOSING THE STAIRS IS TO HAVE 30 MINUTES FIRE RESISTANCE INCLUDING GLAZING* FD20 SD ALL PARTITIONS FD20 ENCLOSING THE STAIRS IS TO HAVE 30 MINUTES FIRE RESISTANCE INCLUDING GLAZING* LANDING SD UP FIRE SEPARATION AT SECOND STOREY LEVEL ALTERNATIVELY THE FIRE SEPARATION CAN BE PROVIDED AT THE BOTTOM OF THE STAIRS AT FIRST FLOOR LEVEL LOUNGE HALL UP BED 1 FD20 BATH Key to works indicated on diagram above FD 20: 20 minute fire resisting door to BS :1987 fitted with intumescent strips rebated around sides & top of door or frame excludes toilets/bathrooms/en-suite providing the partitions protecting the stairs has 30 minutes fire resistance from both sides. Existing doors can be upgraded with proprietary intumescent paint/paper system. (Note: self closing FD30 fire door with intumescent strips, smoke seals & 100mm high fire resistant thresholds is required between the dwelling/garage) SD/HD: Interlinked mains operated smoke alarm/heat alarm with battery back up fitted at ceiling level to BS 5446 & installed to BS 5839 pt6 Note: Where applicable, any glazing in walls enclosing the protected stairs is to have 30 minutes fire resistance and located 1.1m min above the floor level, and unlimited in the fire doors. No glazing is permitted elsewhere including between the dwelling & garage unless 30 minutes fire insulated glazing & beading system is installed

33 Option 2: Protected stairway with alternative exits at ground floor level The new and existing stairs, landings and hallway from the new 3 rd storey down to the ground floor must be protected and enclosed in 30-minute fire resisting construction and the protected stairs must give access to 2 or more FD20 fire doors on the ground floor that discharge into different rooms which are separated from each other by 30 minute fire resisting construction both of each must have external doors for escape as diagram below. KITCHEN/DINING ROOM U/SIDE OF STAIRS TO HAVE 30 MINUTES FIRE RESISTANCE BED 2 BED 3 ALL PARTITIONS ENCLOSING THE STAIRS IS TO HAVE 30 MINUTES FIRE RESISTANCE INCLUDING GLAZING* ENSUIT cupb FD20 FD20 NEW BEDROOM FD20 SD UP ALL PARTITIONS ENCLOSING THE STAIRS IS TO HAVE 30 MINUTES FIRE RESISTANCE INCLUDING GLAZING* FD20 SD UP FD20 ALL PARTITIONS FD20 ENCLOSING THE STAIRS IS TO HAVE 30 MINUTES FIRE RESISTANCE INCLUDING GLAZING* LANDING SD UP FIRE SEPARATION AT SECOND STOREY LEVEL ALTERNATIVELY THE FIRE SEPARATION CAN BE PROVIDED AT THE BOTTOM OF THE STAIRS AT FIRST FLOOR LEVEL LOUNGE BED 1 BATH Key to works indicated on diagram above FD 20: 20 minute fire resisting door to BS :1987 fitted with intumescent strips rebated around sides & top of door or frame excludes toilets/bathrooms/en-suite providing the partitions protecting the stairs has 30 minutes fire resistance from both sides. Existing doors can be upgraded with proprietary intumescent paint/paper system. (Note: self closing FD30 fire door with intumescent strips, smoke seals & 100mm high fire resistant thresholds is required between the dwelling/garage) SD/HD: Interlinked mains operated smoke alarm/heat alarm with battery backup fitted at ceiling level to BS 5446 & installed to BS 5839 pt6 Note: Where applicable, any glazing in walls enclosing the protected stairs is to have 30 minutes fire resistance and located 1.1m min above the floor level, and unlimited in the fire doors. No glazing is permitted elsewhere including between the dwelling & garage unless 30 minutes fire insulated glazing & beading system is installed

34 Option 3: Fire separated 3 rd storey with alternative external/internal fire exit The new top 3 rd storey should be separated from the lower storeys by 30 minute fire resisting construction and provided with an alternative escape route leading to its own final exit as diagram 3. The external stairs must not be within 1.8m of any unprotected opening at the side of the stairs, and no openings are permitted below the stairs- unless the opening is fitted with 30 minute fire resisting glass and proprietary bead system and is permanently sealed shut- subject to adequate ventilation. The external stairs is subject to obtaining planning permission etc where necessary before the works commence on site. (Please contact the FODDC planning department for further information). The alternative fire exit can also be formed internally as a protected stairway. DINING KITCHEN BED 2 BED 3 EXTERNAL FIRE EXIT STAIRS (CAN BE AN INTERNAL PROTECTED STAIRS) SEE GUIDANCE NOTES ENSUIT NEW BEDROOM FD20 SD LANDING FIRE SEPARATION AT SECOND STOREY LEVEL SD SD UP ALTERNATIVELY THE FIRE SEPARATION CAN BE PROVIDED AT FIRST FLOOR LEVEL LOUNGE HALL UP BED 1 BATH PARTITIONS ENCLOSING THE STAIRS IS TO HAVE 30 MINUTES FIRE RESISTANCE INCLUDING ANY GLAZING* Key to works indicated on diagram above FD 20: 20 minute fire resisting door to BS :1987 fitted with intumescent strips rebated around sides & top of door or frame excludes toilets/bathrooms/en-suite providing the partitions protecting the stairs has 30 minutes fire resistance from both sides. Existing doors can be upgraded with proprietary intumescent paint/paper system. (Note: self closing FD30 fire door with intumescent strips, smoke seals & 100mm high fire resistant thresholds is required between the dwelling/garage) SD/HD: Interlinked mains operated smoke alarm/heat alarm with battery back up fitted at ceiling level to BS 5446 & installed to BS 5839 pt6 Note: Where applicable, any glazing in walls enclosing the protected stairs is to have 30 minutes fire resistance and located 1.1m min above the floor level, and unlimited in the fire doors. No glazing is permitted elsewhere including between the dwelling & garage unless 30 minutes fire insulated glazing & beading system is installed

35 Option 4: Residential sprinkler systems for means of escape Where fire safety requirements of the building regulations cannot be met for loft conversions, proposals for fire engineered solutions may be allowed against the requirements of Approved Document B where a risk assessment has been carried out by a suitably qualified and experienced fire engineer and approved by building control before works commence on site. The residential sprinkler system is to be designed and installed to BS 9251:2005 incorporating BAFSA technical guidance note No.1 June 2008 by a suitably qualified specialist- which must be approved by Building Control before works commence on site. If the condition not being met is a ground floor open plan arrangement and the stairs discharge into a habitable open plan area then a partial sprinkler installation to the whole of all connected open plan areas may be used. Fire separation of the route will be required from the upper floor from this open plan area with a 30 minute fire resisting partition and FD20 fire door fitted with intumescent strips. Instead of the separation it may be possible to fully sprinkler the whole dwelling and retain the open plan arrangement with the agreement of building control. With the agreement of the building control, it should be possible to reduce fire protection throughout the dwelling by 30 minutes with the introduction of a full sprinkler installation. Contact: The British Automatic Sprinkler Association (BAFSA)- Sprinklers for Safety: Use and Benefits of Incorporating Sprinklers in Buildings and Structures (2006) ISBN: See also: ISBN technical guidance note no.1 see also IMPORTANT NOTE: The above 4 options need not be followed if the dwelling house has more than one internal stairway, which afford effective alternative means of escape and are physically separated from each other. Fire doors All rooms onto the protected stairs (except bathrooms or toilets providing the enclosing walls have 30 minutes fire resistance) are to be provided with FD20 (or FD30) fire doors to BS :1987 fitted with intumescent strips rebated around sides & top of door or frame with intumescent strips. Any glazing within the fire door or stairway enclosure is to have 30 minutes fire resistance including the beading as detailed in above options. Existing solid/hardwood doors may achieve the required 20 minutes fire resistance or can be upgraded with proprietary intumescent products applied as manufacturers details to achieve 20 minutes fire resistance, as agreed with building control before works commence on site. Contact Cotswold Intumescent Products on: A copy of the purchase invoice will be required by building control on completion to confirm product used. Doors between garages and dwellings to have 100mm high fire resisting threshold step down into the garage, FD30 fire door & frame fitted with an approved mechanical self closing devise, intumescent strips and cold smoke seals. Smoke alarms All floors to be provided with mains operated interconnected fire detection and fire alarm system to BS 5446 & installed in accordance with the relevant recommendations of BS : 2004 to at least a Grade D Category LD3 standard. Self contained mains operated smoke alarms (heat alarms installed in kitchens) with battery back up to be fixed at ceiling level in all circulation areas at each storey level, within 7.5m of all doors to habitable rooms

36 Fire resistance to new storey floor The new 3 rd storey floor storey should be separated from the remainder of the house by 30 minute fire resisting construction e.g. a minimum of 12.5 mm (if existing or 15mm if renewed) plasterboard and skim to ceilings and sides of stud walls and provided with a 20 minute fire door with intumescent strips at either the bottom or top of the new stair leading to the loft conversion. Permitted building openings in relation to a boundary: Openings within 1.0m of a boundary An unprotected opening of 1m 2 (e.g. window) is permitted every 4.0m on the same building face. This unprotected opening can consist of two or more smaller openings within an area of 1m 2 (openings less than 0.1m 2 is permitted every 1500mm on the same building face). There are no restrictions on dimensions between openings separated by compartment walls & floors. Please refer to Diagram 20 of ADB4 Volume 1 for full details. Openings more than 1.0m from a boundary Permitted unprotected openings to be in compliance with table below for buildings not exceeding 3 storeys high (excludes basements) or more than 24m long. Table 18: Permitted unprotected areas in relation to a relevant boundary Minimum distance between side of Maximum total area of unprotected building & relevant boundary openings 1.0m 5.6m2 2.0m 12m2 3.0m 18m2 4.0m 24m2 5.0m 30m2 6.0m no limit If sprinklers are fitted throughout the building to BS 9251, the above distances can be reduced by 50% (min 1.0m) or the unprotected opening area doubled. Please refer to ADB4 Volume 1 for full details relating to space separation and other methods of calculating unprotected areas. Fire resistance to elements of structure etc Please refer to Table A1: Appendix A of ADB: Volume 1 for full details. Table 19: Fire resistance to common elements of structure etc Building element Fire resistance Method of protection in minutes Beam, column or frame 30 All exposed faces Load bearing wall 30 Each side separately Upper floors (Max 3 storey building) 30 Underside Roof (only if forming part of an escape route) 30 Underside External walls: (i) Less than 1.0m to relevant boundary (ii) More than 1.0m to relevant boundary (max 3 storey building) Each side separately From inside building Walls & upper floors separating an integral garage from the dwelling 30 From garage side Compartment walls & floors separating Dwellings 60 Each side separately Protected stairs & lift shaft (not forming part of a compartment wall) 30 Each side separately Cavity barriers etc 30 Each side separately

37 Note: 13mm plasterboard & skim finish applied to 100 x 50mm timber stud partitions/ ceiling/ floor joists as detailed in this specification will achieve 30 minutes fire resistance, two layers of 13mm plaster board (joints staggered) will achieve 60 minutes fire resistance. Masonry walls detailed in this specification will achieve 60 minutes fire resistance. Surface spread of flame: wall & ceiling linings Table 20: Surface spread of flame: Classification of wall & ceiling linings Please refer to Table 1: Section 2 of ADB: Volume 1 for full details. Location National class European class Small rooms upto 4m2 & 3 D-s3,d2 Domestic garages upto 40m2 Other rooms over 4m2 inc 1 C-s3,d2 Garages over 40m2 & Circulation spaces within Dwellings (e.g. hall, stairs & landings) Note: Plaster on masonry walls & plaster board & skim linings in this specification will achieve class 1. Exposed timber linings should be treated with a proprietary treatment to achieve the above classifications. IMPORTANT NOTE: Means of escape windows are not required where the stairs is protected as detailed above

38 Part C: Site preparation and resistance to contaminants & moisture Horizontal damp proof courses & trays (dpc s) Horizontal Dpc s and Dpc trays with weep holes at 1.0m ctrs to be provided 150mm above ground level continuous with and sealed to the floor Dpm & radon dpc tray. Vertical damp proof courses & trays etc (dpc s) Stepped and horizontal Dpc/cavity trays are to be provided over all openings, roof abutments/projections and over existing walls with different construction or materials. Install vertical dpc or proprietary insulated cavity closers at all closings, returns, abutments to cavity work and openings etc. Part D: Cavity wall filling with insulation by specialists The suitability of the cavity wall for filling must be assessed before the works is carried out by an insulation specialist in accordance with BS 8208: Part 1: The insulation specialist carrying out the work must hold or operate under a current BSI Certificate of Registration of Assessed Capability for the work being carried out. The insulation material must be in accordance with BS 5617: 1985 and the installation must be in accordance with BS 5618: 1985 The Installation of urea-formaldehyde (UF) in cavity walls is to be carried out in compliance with paragraphs of ADD1 Part E: Resistance to the passage of sound New Internal walls & floors in loft conversion Sound insulation details between internal walls & floors separating bedrooms or a room containing a WC and other rooms to be carried out in accordance with the relevant details contained within this guidance and Approved Document E. New/existing party walls and floors in loft conversion Sound insulation details for new party walls and floors and upgrading of existing party walls and floors to be carried out in accordance with the relevant details contained within this guidance and Approved Document E

39 Part F: Ventilation Purge (natural) ventilation Purge (natural) ventilation to be provided to all habitable rooms equal to 1/20 th (5%) floor area where the external windows/doors open more than 30 degrees and increased to 1/10 th (10%) of the floor area where the windows opens between degrees. Window openings which open less than 15 degrees is not suitable for purge ventilation and alternative ventilation details are required as detailed below and in compliance section 5 & Appendix B of Approved Document F1. Purge (natural) ventilation openings to habitable rooms to be typically 1.75m above floor level. The area of external windows, roof windows & doors should not exceed 25% of the usable internal floor area otherwise SAP calculations may be required from a suitably qualified person to confirm design flexibility where they exceed 25% of the usable floor area. (ii) See the relevant section in this guidance for permitted unprotected external openings in relation to relevant boundaries. Means of escape windows to be fitted with proprietary hinges to open to the minimum required clear width of 450mm. Escape windows must have minimum clear opening casement dimensions of 0.33m² and 450mm (typically 450mm wide x 750mm high), located within mm above floor level to all bedrooms and habitable rooms at 1st floor level and inner habitable rooms on the ground floor. Windows above the ground floor storey and within 800mm of floor level are to be provided with containment/ guarding/ proprietary catches which should be removable (child proof) in the event of a fire. Where escape windows cannot be achieved in two story buildings, direct access to a protected stairs (or protected route to inner rooms) is acceptable in compliance with the guidance above. Escape windows are not required where protected routes are provided in compliance with this guidance. Mechanical extract ventilation & fresh air inlets for rooms without purge ventilation Mechanical extract ventilation & fresh air inlet are required for habitable rooms without purge (natural) ventilation which must designed by a ventilation specialist having a minimum of 4 air changes per hour & manually controlled in compliance section 5 of Approved Document F1. Background ventilation Background ventilation to be provided equivalent to 8000mm² to habitable rooms and 2500mm 2 to wet rooms via hit and miss or 2 stage catches fitted to windows Mechanical extract ventilation rates Mechanical ventilation is to be provided to the rooms listed below directly ducted to the outside air equivalent to the following rates. Kitchen 30 litres per second over hob or 60 litres elsewhere Utility room 30 litres per second Bathroom 15 litres per second (including shower rooms & en-suites) Toilet 6 litres per second W/C (with or without a window) General requirements for mechanical extract ventilation Mechanical ventilation to rooms without open able windows to be linked to light operation and have 15 minutes overrun and a 10mm gap under the door for air supply. Fans must not be installed in rooms containing open flue appliances unless the interaction of mechanical ventilation & open flue heating appliances is checked and certified by an approved method & suitably qualified person as contained in ADJ. Mechanical ventilation to be ducted in proprietary insulated ducts to outside through walls to proprietary vent or through roof space to proprietary matching tile /soffit vent

40 Part G: Sanitation, hot water safety and water efficiency Sinks with hot and cold running water is to be provided in all food preparation areas, bathrooms to be fitted with either a bath or shower. Hot & cold water taps to wash basins, baths, showers & sinks including external taps to have water from a wholesome water supply. Outlets from domestic hot water storage vessels to be fitted with an in line hot water supply tempering valve to prevent water temperatures exceeding 60 ºC. Where a building is converted into a new dwelling, the bath should be fitted with an in line blending valve fixed at 48 degrees centigrade. Hot water storage systems to be restricted to 100 degrees C max and outlets from domestic hot water storage vessels to be fitted with an in line hot water supply tempering valve to prevent water temperatures exceeding 60 degrees C max. Hot water storage vessels to be fitted with a non-self-setting energy cut out to instantly disconnect the power supply. Wash hand basins to be provided in all rooms containing a w/c and a door must separate the w/c from any food preparation area in a dwelling Water tanks/cisterns must have an adequate designed flat platform base to support the proposed loads. Pumped small bore foul water drainage from a toilet is only permitted if there is also access to a gravity draining toilet in the same dwelling. Proprietary pumped foul water macerator systems must have BBA or other approved accreditation and fitted in compliance with manufacturers details to a suitable foul water drainage system. Commissioning certificates for fixed building services are required on completion with copy sent to building control

41 Part H: Drainage and waste disposal H1: Foul water drainage Foul, rain & storm water drainage systems Both storm and foul drainage to consist of 100mm diameter UPVC proprietary underground drainage laid at a minimum gradient of 1:40 where serves up to one wc or 1:80 where serves two or more wc s, surrounded in pea/single size gravel a minimum of 900mm deep in drives and roads and 400mm elsewhere, unless provided with a 100mm reinforced concrete slab with compressible material under and 300mm min bearing on original ground. Proprietary UPVC 450mm diameter inspection chambers to be provided at all changes of level and or direction and at 45m maximum spacing in straight runs up to 1.2m in depth. All gullies to be trapped and have rodding access where serving branches. Inspection chamber covers to be mechanically fixed and suitable for vehicular loads in drives and roads and double sealed with holding down bolts to covers & frames in buildings. Foul water to be discharged to new or existing facilities as shown on plans/specification and storm water from individual down pipes to be piped 5m away from buildings and to be disposed in a separate surface water sewer via trapped gullies or to soakaways minimum 2m³ clean filled rubble soakaways per rain water pipe serving a roof area upto 30m2, covered with polythene and top soil or to other methods as shown on the drawing/specification. Soakaways in clay sub soils or serving roof areas exceeding 30m2 per rwp to be designed in accordance with BRE Digest 365 or by a specialist (i.e. Hydrologist). Rain/surface water systems cannot be connected to foul water drains without the written permission of the relevant Water Authority. Foul drainage systems to low lying buildings or basements which carry storm water or other vulnerable drainage systems should be provided with anti flood protection such as one way valves, etc, to prevent flooding and sewerage entering the building. Waste pipes All W/Cs to have trapped outlet connected to 100mm diameter pipes, and to be provided, with a wash hand basin with hot and cold running water. Sanitary appliances such as wash hand basin, baths, showers, sinks etc, to be provided with 50mm diameter waste pipes laid to falls and 75mm deep seal traps. Where waste pipe runs exceed 4m BBA approved air admittance valves are to be fitted above appliance spill over level. Waste pipes to either discharge below trapped gully grating or into soil and vent pipes via proprietary waste manifolds or bossed junctions. Internally all waste and drainage pipes to have rodding access/eyes at changes of direction and be adequately clipped/supported and provided with 30 minutes fire protection where passing through floors

42 H2: Septic tanks, sewage treatment systems & cesspools Existing septic tank & effluent drainage Where additional drainage effluent is to be connected to the existing septic tank/treatment system, it should be checked by specialist and sizes/condition of tank/system to be confirmed suitable for treatment of additional effluent. Non mains foul drainage waste water treatment systems Non mains drainage systems are to be used only where connection to the mains drainage system is not possible. Either septic tank or sewage treatment system to be installed as agreed with Building Control to suit specific ground conditions. No septic tank/ sewage treatment system and associated secondary treatment is permitted by the Environment Agency in prescribed Zone 1 ground water source protection zones. Where no other option is feasible, the installation of a cesspool is to be agreed with Building Control & the Environment Agency. Septic tanks Septic tanks to consist of a watertight chamber, water proof from both sides and the sewage is liquefied by anaerobic bacterial action in the absence of oxygen assisted by the natural formation of a surface scum or crust. Sludge settlement at the base of the tank must be removed annually. Discharge from tanks to be taken to drainage fields, drainage mounds or wetlands/reed beds for secondary treatment as detailed below. Proprietary factory made septic tanks to be designed and constructed to BS EN and installed in compliance with manufacturer s details, or Non proprietary septic tanks constructed in situ to be designed and constructed to a drainage specialist s design, approved by Building Control before the works commence on site. Typically, the tank consists of two chambers constructed using 150mm minimum thick concrete base C25P mix to BS 5328, 220mm thick engineering quality brickwork walls (or concrete), mortar mix 1:3 cement/sand ratio with designed heavy concrete roof slabs. 100mm diameter Inlet and outlet dip pipes designed to prevent disturbance of the surface scum, inlet pipe laid at a flatter gradient for at least 12 meters before it enters the tank. Septic tanks to be fitted with durable lockable lids or covers for emptying and cleaning, and inspection chamber fitted on the discharge side of tank for sampling of the effluent. Septic tanks to be sited 7m from any habitable part of any building and preferably down slopes and have a minimum capacity of 2,700 litres for upto 4 users & increased by 180 litres for each additional user. (Recommended size of septic tank to be 3,800 litres minimum). A notice plate must be fixed within the building and include the following information: Address of the property; location of the treatment system; description of the septic tank and effluent drainage installed; necessary maintenance to be carried out (including monthly checks of the apparatus and emptying of the tank every 12 months by a licensed contractor) and a statement that the owner is legally responsible to ensure that the system does not cause pollution, health hazard or nuisance. Consultations are to be carried out with Building Control and The Environment Agency before any works commence on site. It is the Occupiers responsibility to register the effluent discharge as an exempt facility with the Environment Agency for discharges of 2m3 or less per day to the ground from a septic tank

43 Sewage treatment systems Proprietary sewage treatment systems treat sewage by an accelerated process to higher standards than that of septic tanks, and are to be factory made, designed and constructed to BS EN (if less than 50 persons otherwise to BS 6297: 1983 Code of Practice for design and installations of small sewage treatment works and cesspools and BBA certification or other approved accreditation), installed and maintained in compliance with the manufactures details and fitted with a uninterruptible power supply (or 6 hours power back up). Note: only treatment systems suitable for intermittent use should be used for holiday lets or similar where the system is unused for periods of time. Sewage treatment system to be sited 7m from any habitable part of any building and preferably down slopes and have a minimum capacity of 2,700 litres for upto 4 users & increased by 180 litres for each additional user. Discharges from sewage treatment systems can be taken to a water course or alternatively a designed drainage field, drainage mound, wetlands or reed beds as detailed below. A notice plate must be fixed within the building and include the following information: Address of the property; location of the treatment system; description of the sewage treatment system and effluent drainage installed; necessary maintenance to be carried out in accordance with the manufacturers details and a statement that the owner is legally responsible to ensure that the system does not cause pollution, health hazard or nuisance. Consultations should be carried out with Building Control and The Environment Agency before any works commence on site. It is the Occupiers responsibility to register the effluent discharge as an exempt facility with the Environment Agency for discharges of 5m 3 or less per day to a surface water course or 2m 3 or less per day to the ground from a sewage treatment system. Treatment of sewage from septic tanks & sewage treatment systems Drainage fields Drainage fields to consist of irrigation pipes constructed below ground allowing partially treated effluent to percolate into the ground and further biological treatment in the aerated soil layers. Construction of drainage fields to be carried out as tank/system manufacturers details and BS 6297: A1:2008. See typical section detail and drainage field layout below. The drainage field area is calculated from the percolation test results which should have a suggested minimum area of 30m x 0.6m wide subject to percolation test results and number of users and approved by Building Control before works commence on site. See below for percolation test procedure. Drainage fields to be located 10m from any water course, 50m from any point of water abstraction, 15m from any building & sufficiently far from any other drainage areas so the overall soakage capacity of the ground is not exceeded. Water supply pipes, access roads, drives or paved areas etc must not be located within the drainage areas. Drainage mounds Drainage mounds to consist of drainage fields constructed above the ground allowing further biological treatment of the partially treated effluent in the aerated soil layers. Drainage mounds to be used where there is a high water table level, impervious or semi water logged ground. Drainage mounds and drainage mound areas should be designed by a drainage specialist for particular ground problems and approved by Building Control before works commence on site. See diagram 2 of ADH for typical drainage mound construction details

44 Drainage mounds to be located 10m from any water course, 50m from any point of water abstraction, 15m from any building & sufficiently far from any other drainage areas so the overall soakage capacity of the ground is not exceeded. Water supply pipes, access roads, drives or paved areas etc must not be located within the drainage areas. Wetlands/reed beds In situations where drainage fields or mounds are not suitable, wetland treatment systems consisting of manmade reed beds can be constructed as either vertical or horizontal flow reed bed systems for the purification of the partially treated effluent by filtration, biological oxidization, sedimentation and chemical precipitation as the partially treated effluent passes through gravel beds and root systems of wetland plants. Wetlands should not be constructed in shaded or severe winter areas. Vertical or horizontal flow wetland treatment systems should be designed by a drainage specialist for particular ground problems and approved by Building Control before works commence on site. A notice plate must be fixed within the building and include the following information: Address of the property; location of the treatment system; description of the sewage treatment system and effluent drainage installed; necessary maintenance to be carried out in accordance with the drainage specialists details and a statement that the owner is legally responsible to ensure that the system does not cause pollution, health hazard or nuisance. See diagram 3 of ADH for typical horizontal flow reed bed system and diagram 4 of ADH for typical vertical flow reed bed system. Percolation test method to calculate area of drainage field for septic tanks or sewage treatment systems. Step 1: Excavate a test hole 300mm square x 300mm deep below proposed invert level of the drainage field trench bottom Step 2: Fill the test hole with water and allow drain away over night Step 3: Refill to a depth of 300mm and note time taken in seconds to drain away from 75% full to 25% full (i.e. 150mm drop in level from 225mm to 75mm) Step 4: Repeat the procedure in two more test holes and calculate the average of the three results as follows: test 1 + test 2+ test 3 = average time taken 3 Step 5: Calculate the Vp (average time in seconds for the water to drop 1mm) as follows: For example: If average time above took 2100 seconds (i) Divide 2100 seconds by 150mm depth of water (ii) 2100 = 14 Vp* (see note below*) 150 (iii) Area of trench = number of persons to use property X Vp X 0.25 Therefore: 5 persons X 14 X 0.25 = 17.5m 2 of effluent drain required. (iv) To calculate actual length of trench divide 17.5m 2 by width of the trench required therefore: 17.5m 2 = (Minimum permitted area is 30m long x 0.6m wide) 0.6m wide * Vp should range between 12 and 100 to be successful; otherwise the system should be designed by a drainage specialist

45 Diagram 14: Typical section through a septic tank/sewage treatment system drainage field (not to scale) Cross section detail of a septic tank/sewage treatment effluent drainage soakaway trench (not to scale) Ground level Back fill with excavated material 1200g polythene layer 100mm diam ridgid Upvc slotted pipe (slots laid down), laid at 1: mm diam clean stone below & covering pipe 600 to 900mm wide trench, as drainage field layout belowminimum 30m length of pipe work 50mm 100mm diam pipe 150mm At least 1.0m from winter water table level Minimum depth 500mm Winter water table level Diagram 15 : Typical drainage field plan layout (not to scale) Distribution/sampling chamber 600mm wide trench as guidance details 2000mm min separation Inlet 2000mm min non slotted upvc pipe Septic tank/sewage treatment plant as guidance details 2000mm min separation 100mm diam perforated effluent distribution pipes (perforations laid down) 30m minimum length of rigid upvc pipes Note: All effluent drainage pipe work from the tank to be laid at 1:200 gradients etc as guidance details

46 H3: Rainwater drainage and harvesting Rainwater gutters and down pipes Rainwater gutters and down pipe sizes and number to be suitable for roof area to be drained in compliance with the table below, and fixed in compliance with manufactures details. See H3 of ADH for further information Table 21: Gutter sizes & pipe outlet sizes for drainage of roof areas Max effective roof area m2 Gutter sizes (mm Outlet sizes (mm diam) diam) The sizes above refer to half round gutters & round rain water pipes Rainwater/ grey water harvesting storage tanks & systems Rainwater harvesting system to be designed, supplied, installed, and commissioned by specialist to supply rainwater to sanitary appliances. Below drainage pipework as foul water pipe guidance details above. Grey water systems designed for use within the building is to be designed, manufactured, installed and commissioned by a suitably qualified and experienced specialist. Grey water to be treated prior to use in toilets etc by an approved method. Overflow from the rain water storage tank is to discharge to a designed soakaway system constructed 5m from any building & septic tank soakaway system. Grey water & rainwater tanks & systems should: Prevent leakage of the contents, ingress of subsoil water & should be ventilated Have an anti backflow device on any overflow connected to a drain or sewer Have a corrosion proof locked access cover for emptying & cleaning Supply pipes from the grey water or rain water collector tanks to the dwelling must be clearly marked as either GREY WATER or RAIN WATER. Guidance should be followed in par of App Doc H2, App Doc G of the Building Regulations and the Water Regulations Advisory Scheme Leaflet No: , and BS 8515:2009. Surface water drainage around the building Paths and paved areas around the building to have a non slip finish and if not porous propriety design to be provided with a cross fall of 1:40 1:60 and a reverse gradient of at least 500mm away from walls of building. Surface water to be disposed of by an adequately sized and roddable drainage system via soakaways, or other approved means

47 Part J: Combustion appliances & fuel storage systems Space & hot water heat producing appliances in general Space and hot water heating method as detailed on the plans/specification. Heating to be supplied from new or extended gas/lpg/oil fired wall/floor mounted condensing balanced flue boiler with the flue discharging 600mm minimum away from openings into the building and protected with a proprietary wire basket to boiler manufacturers specification. Boilers to have a SEDBUK efficiency above 90% to comply with Building Regulations as amended in October 2010 for gas/ LPG/oil and must be provided with separate controls for heating and hot water with a boiler interlock, timer, and thermostat radiator valves to each room. Un-vented hot water systems require safety devices including non self setting energy cut out & temperature release valve and thermostat. Safety valves from vented hot water systems must discharge safely. Hot water vessels to be insulated with 35mm minimum thickness of PU foam and both heating and water pipes to be insulated with proprietary foam covers equal to their outside diameter within 1m of the vessel and in unheated areas. Hot water storage must not exceed a temperature of 100 degrees centigrade. Gas installations to be installed and comply with BS 5440, BS 5546, BS 5864, BS5871, BS 6172, BS 6173 and BS Oil installations to be installed and comply with BS 5410, BS 799. All space and hot water systems must be installed, commissioned, calibrated and certified by a suitably qualified person or installer registered with an appropriate competent persons scheme and details supplied to Building Control and the owner along with the operating manuals, etc before the building is completed/occupied. Solid fuel appliances up to 50kW rated output Construction of open fire place with recess & hearth Fire place walls to consist of non combustible material of at least 200mm in thickness to the side 100mm thick in the back wall recess, lined with suitable fire bricks. The hearth to be at least 125mm thickness (or 12mm thick if provided over a concrete floor slab) of non combustible materials with projections at least 150mm to the sides of the side jambs and 500mm in front of the jambs. Free standing stove with hearth Free standing stoves & hearths to be positioned 150mm minimum away from enclosing non combustible walls at least 100mm thick. Hearths to be at least 125mm thickness (or 12mm thick if provided over a 100mm thick concrete floor slab),constructed of non combustible materials with projections at least 150mm to the sides & rear of the appliance and 300mm in front of the appliance door. Air supply (ventilation) to solid fuel appliances Permanently open combustion air vents ducted to outside are to be provided in the same room as the solid fuel appliance with a total free area in compliance with the table below (see Table 1 of ADJ for further information)

48 Table 22: Air supply (ventilation) to solid fuel appliances Type of appliance Amount of ventilation Open fire place with no throat (i.e. under a 50% of the cross section area of the Canopy) Flue Open fire place with throat or for simple fire openings: 500mm wide 450mm wide 400mm wide 350mm wide Enclosed stove with flue draught stabilizer In new extension (good air tightness) In existing building (if air tightness improved- use figure for new extension) Enclosed stove with no flue draught stabilizer In new extension (good air tightness) In existing building (if air tightness improved- use figure for new extension) 50% of the cross section area of the Throat opening area 20,500mm 2 18,500mm 2 16,500mm 2 14,500mm 2 850mm 2 /kw of appliance rated out put 300mm 2 /kw for first 5kW & 850mm 2 / kw of balance of appliance rated out put 550mm 2 /kw of appliance rated out put 550mm 2 /kw for appliance rated out put Above 5kW Carbon monoxide alarms Mains operated carbon monoxide alarm is required at ceiling level in the same room as the solid fuel appliance, which must be either battery operated in compliance with BS EN 5029: 2001: or mains operated with sensor failure warning device in compliance with BS EN 5029: Type A Carbon monoxide alarm to be positioned on the ceiling at least 300mm from walls, or if located on the wall as high up as possible (above any doors or windows) but not within 150mm of the ceiling, and between 1m and 3m horizontally from the appliance Table 23: Sizes of flues in chimneys Installation Fire place with opening up to 500 x 500mm Fire place with opening more than 500 x 500mm or exposed on both sides Closed appliances* (stove, cooker, room heater & boiler) up to 30kW rated output 30-50kW rated output Closed appliances up to 20kW rated output which-burns smokeless/low-volatile fuel, or complies to the Clean Air Act Pellet burner which compiles to the Clean Air Act Minimum internal flue sizes 200mm (diameter, rectangular or square) Area equal to 15% of the total face area of the fireplace opening. (note: total face areas more than 15% or 0.12m 2 to be designed by heating specialist) (diameter, rectangular or square) 150mm 175mm See table 2 of ADJ See table 2 of ADJ

49 Construction of masonry chimneys Chimneys to be constructed in external quality frost resistant materials 100mm minimum thickness (increased to 200mm where separates another fire compartment or another dwelling), using brick, dense blocks or reconstituted/natural stone to match the existing, with suitable mortar joints for the masonry as the masonry manufacturers details with any combustible material kept at least 50mm away from the walls containing flues. Line chimney with manufactured flue liners installed in compliance with manufacturers details as follows: (i) Clay flue liners to BS EN 1457:2009: Class A1 N1 or Class A1 N2, to be laid vertically and continuously socket up (jointed with fire proof mortar) from appliance with a minimum diameter in compliance with table 22 (ii) Concrete flue liners to BS EN 1857:2003: Type A1, A2, B1 or B2 to be laid vertically and continuously socket up (jointed with fire proof mortar) from appliance with a minimum diameter in compliance with table 22 (iii) Liners whose performance complies to BS EN 1443:2003: designation: T400 N2 D 3 G with a minimum diameter in compliance with table 22 Backfill gaps between masonry and flue liners with a weak mix concrete using 1:6 ordinary Portland cement and vermiculite. Build in code 5 lead flashings (including apron & lay board flashings) & dpc tray into chimney as work proceeds, 150mm above all roof/wall abutments as necessary & terminate chimney with a proprietary chimney pot to match the internal flue sizes. Construction of factory made flue block chimneys Construction of factory made flue block chimneys are to be carried out in compliance with paragraphs of ADJ, and appliance manufacturer s details. Construction of factory made metal chimneys Construction of factory made metal chimneys are to be carried out in compliance with paragraphs of ADJ, and appliance manufacturer s details. Factory made metal chimneys are to be concealed in the building in compliance with paragraph 1.47 & diagrams 13 & 14 of ADJ. Configuration of flues serving open flue appliances Flues to be constructed straight and vertical with no more than a 90 degree bend with cleaning access where the flue connects to the appliance and no more than two 45 degree bends (to the vertical) in the flue configuration in compliance with paragraph of ADJ,. Inspection & cleaning openings in flues Inspection & cleaning openings should be air tight using proprietary factory made components compatible with the flue system, fitted & located to allow sweeping of the flue in compliance with appliance manufacturers details Interaction of mechanical extract vents & opened flue solid fuel appliances Where a kitchen contains an opened flue- solid fuel appliance, confirm extract ventilation will not be installed in the same room as the appliance, or alternatively seek further guidance from HETAS

50 Chimney heights Chimney height not to exceed 4.5 times its narrowest thickness. Chimney/terminal to discharge at a minimum height of: 1.0m above flat roofs 1.0m above opening windows or roof lights in the roof surface 0.6m above the ridge Outside of a zone measured 2.3m horizontally from the roof slope 0.6m above an adjoining or adjacent building that is within 2.3m measured horizontally (whether or not beyond the boundary) Please refer to Diagram 17 of ADJ for full details Alternative heating producing appliances as detailed on the drawing/specification to be in compliance with ADJ. Repair/relining of existing flues Repair /relining of existing flues to be carried out by a suitably qualified and experienced specialist. Re-use of existing flues to be inspected, tested and certified by a suitably qualified and experienced specialist prior to use as suitable for solid fuel appliances. Relining of existing flues to be carried out in compliance with BS EN 1443:2003: designation: T400 N2 D 3 G with minimum diameters in compliance with table 22 using lining systems suitable for solid fuel appliances as follows: (i) Factory made flue lining systems in compliance with BS EN :2003 or BS EN :2004 (ii) Cast in-situ flue lining system in compliance with BS EN 1857:2003+A1:2008 Notice plates for hearths & flues Notice plates for hearths & flues should be permanently displayed next to the flue (or electricity consumer unit or water stop tap) detailing the property address; location of installation (room); type of installation the flue is suitable for; size & construction of flue, if suitable for condensing appliance, installation date, and any other information (optional). Appliances other than solid fuel Interaction of mechanical extract vents & opened flue combustion appliances Gas appliances Where a kitchen contains an opened flue- gas appliance, the extract rate of the kitchen fan should not exceed 20 l/s (72m3/hour) and the appliance should be tested and certificated by a suitably qualified and registered gas engineer that the combustion appliance operates safely whether or not the fans are running. Oil appliances Where a room contains an opened flue- oil appliance, the extract rate of the fan should not exceed 40 l/s for an appliance with a pressure jet burner and 20l/s for an appliance with a vaporising burner. Gas heating appliances up to 70kw Gas burning appliances up to 70kW to be installed, commissioned and tested in compliance with section 3 of ADJ, and the Gas Safety (installation & use) Regulations. All works to be to be carried out by an installer registered with Gas Safe. Copy of commissioning certificates to be issued to Building Control on completion of the works

51 Oil heating appliances up to 45kW Oil burning appliances up to 45kW to be installed, commissioned and tested in compliance with section 4 of ADJ. All works to be to be carried out by an installer registered with OFTEC. Copy of commissioning certificates to be issued to Building Control on completion of the works. Renewable energy Installations Renewable energy systems must be installed, commissioned, calibrated and certified by a suitably qualified person or specialist installer registered with an appropriate competent persons scheme (where applicable) and details supplied to Building Control and the Owner along with the operating manuals, etc for the following installations: Solar photovoltaic (pv) roof/wall panels for producing electricity Biomass space heating & hot water systems Wind energy turbines for producing electricity Hydro-power systems for producing electricity Solar water heating roof/wall panel systems, fitted with an additional heating source to maintain an adequate water temperature Ground/air source heat pumps for space heating & hot water systems All roof / wall structures must be adequate to support the above installations in compliance with manufacturers details or calculations & details from a suitably qualified person which must be approved by Building Control before works commence on site. Provision of information- commissioning certificates (testing) Copy of installers commissioning certificate to be sent to building control on completion of the work. Fuel storage tanks LPG tanks and cylinders up to 1.1 tonnes LPG tanks and cylinders up to 1.1 tonnes to be positioned in the open air at least 3m from buildings or boundaries. LPG cylinders to be positioned in the open air on a minimum 50mm thick concrete base, securely chained to the wall and positioned at least 250mm below and 1m from any openings horizontally into the building such as windows, combustion, vents or flue terminals and 2m from un-trapped drains or cellar entrances. Oil tanks up to 3500 litres Oil tanks up to 3500 litres to be positioned in the open air on a concrete base with a minimum thickness of 50mm extending a minimum of 300mm beyond the tank base and be positioned a minimum of 1.8m from buildings or flues and 760mm from boundaries. They should also be provided with a proprietary fire resistant pipe and valve system. Where there is a risk of pollution to water courses, open drains including inspection chambers with loose covers, the tank should be either internally bunded or be provided with an impervious masonry bund equal to capacity of 110% of its volume. Where any of the above requirements cannot be met- please contact building control for further guidance

52 Part K: Protection from falling, collision and impact Internal stairs, landings and changes in level of 600mm or more Stairs to be constructed (and finished) in materials to Clients choice to BS 5395 & BS 585 as detailed below:- (Spiral & helical stairs to be designed to BS 5395: Part 2) Stair pitch not to exceed 42 and design to be based upon dimensions taken from site and drawing. Rise and going to be level and equal to all steps and to fall within the following separate classes:- Any rise between 155mm-220mm used with any going between 245mm- 260mm, or Any rise between 165mm-200mm used with any going between 223mm- 300mm. (Twice the rise plus the going must be between 550 & 700mm) Diagram 15: Measuring rise & goings (not to scale) tread open riser Note: treads should over lap at least 16mm riser nosing top surface of tread rise top surface of tread Note: going dimention to be measured from nosing to nosing going ` Stair to have a minimum headroom of 2000mm above stair pitch line and to be provided with landings clear of any door swing top and bottom equal in length to the width of the stairs. If doors open across a bottom of a landing- a clear 400mm space must be maintained across the width of the flight. There is no minimum stair width for new extensions or replacement stairs in existing dwellings. Handrails must be provided on one side of the stairs, at a height mm above floor/nosing levels and continuous throughout their length. All guarding is to be at a minimum height 900mm above floor/nosing levels and continuous throughout their length, with non climbable vertical balustrading, no gaps to exceeding 100mm and all constructed to resist a horizontal force of 0.36kn/m. All open treads, gaps etc should not exceed 100mm. Typical staircase construction details: side strings ex. 230 X 35mm, capping ex. 32 X 63mm, treads 25mm thick, risers in 12.5mm thick plywood, newel posts ex. 75 X 75mm, handrails ex. 75 X 63mm, balustrades ex. 32 X 32mm at 125mm ctrs fixed into proprietary timber head & base rebated capping

53 Diagram 16: Typical internal stair case & guarding construction details (not to scale) At least 2000mm clear head room (can be reduced to 1900mm at the centre of the stairs & 1800mm at the side in loft conversions) Handrail & guarding at least 900mm high above landing level Newel post Handrail & guarding at least 900mm high above pitch line non climable balustrades & no gaps to exceed 100mm trimmer joists Landing Landings must be level & equal in length to the smallest width tread All guarding must resist a horizontal force of 0.36kn/m pitch line At least 2000mm clear head room (can be reduced to 1900mm at the centre of the stairs & 1800mm at the side in loft conversions) Note: No opening to allow the passage of 100mm diam sphere rise outer string Flight Max 42 degree pitch Landing External stairs, landings and changes in level of 600mm or more External stairs & landings As internal stair guidance details above Note: Landings to be clear of any obstructions. A door may swing accross a landing at the bottom of a flight but must allow a 400mm min clear space accross the full width of the flight clear of any door swing External guarding Guarding to external stepped access/openings/balconies to be at least 1100mm high provided with non climbable vertical balustrading, with no gaps exceeding 100mm and constructed to resist a horizontal force of 0.74kn/m. All open treads, gaps etc should not exceed100mm. Guarding to upper storey window openings/other openings within 800mm of floor level Opening windows located above the ground floor storey with openings within 800mm of floor level must be provided with non climbable containment/guarding or proprietary catches which should all be removable (but child proof) to means of escape windows in the event of a fire. All gaps etc to containment/guarding should not exceed 100mm

54 Part L: Conservation of fuel and power in existing dwellings Listed buildings, conservation areas & ancient monuments If the proposed energy efficiency requirements will unacceptably alter the character or appearance of a historic/listed building/ancient monument or building within a conservation area, then the energy efficiency standards may be exempt or improved to what is reasonably practical or acceptable and would not increase the risk of deterioration of the building fabric or fittings in consultation with the local planning authorities conservation officer in compliance with paragraphs of AD L1B. Areas of external windows, roof windows & doors Area of external windows, roof windows & doors should not exceed the sum of 25% of the usable internal floor area of the extension, plus the total area of any windows or doors which as a result of the extension works, no longer exists or are no longer exposed in compliance with paragraph 4.2 of ADL1B. Where necessary, SAP Calculations to be sent to building control to confirm design flexibility where area of external windows, roof windows & doors exceed 25% of the usable floor area. Building control can provide SAP calculations to confirm design flexibility where the area of external windows, roof windows & doors exceed 25% of the usable floor area if required. Please contact Building Control on for more details New thermal elements External glazing External glazing insulation details to comply with U-values for external windows, doors & roof lights in compliance with paragraphs & Table 1of ADL1B as follows: Table 24: U Values for new external windows & doors including roof windows Fitting Insulation standard U value: W/m 2.K Windows, roof window or roof light 1.6 (or WER as Band C of par 4.22 of ADL1B) Doors with more than 50% glazing 1.8 Other doors 1.8 Replacement windows/doors 1.2 centre pane- if external appearance of facade or character of the building is to be maintained Typically, double glazed units with 16mm air gap and factory sealed with low-e coating & Argon filled in timber or Upvc frames will achieve a U-value of 1.6. Manufacturers details will be required for other types of frames to confirm minimum U values in compliance with the above table. All external doors, windows, roof lights to be draft stripped Closing around window & door openings Checked rebates should be constructed to window/door reveals or proprietary finned insulated closers should be used. Checked rebates are where the outer skin masonry/skin projects across the inner skin by at least 25mm, the cavity is closed by an insulated closer and the window or door is fully sealed with mastic or similar externally. Sealing Measures All external door and window frames, service penetrations to walls, floors and ceilings, etc, should be sealed both internally and externally with proprietary sealing products such as proprietary waterproof mastic, expanding foam or mineral wool or tape to ensure air tightness

55 External Walls, roofs, floors & swimming pool basin External Walls, roofs, floors & swimming pool basin to comply with new thermal element requirements in compliance with paragraphs & Table 2 of ADL1B as follows: Table 25: U Values for new external walls, roofs, floors & swimming pool basin Element Insulation standard U value: W/m 2.K Walls (exposed & semi exposed) 0.28 Pitched roof & dormer windows with 0.16 insulation at ceiling level Pitched roof & dormer windows with 0.18 insulation at rafter level Flat roof or roof with integral insulation 0.18 Floors 0.22 Swim Swimming pool basin (walls & floor) 0.25 See Part A: Structure for wall, roof & floor construction details incorporating the above insulation requirements. Renovation/upgrading of existing thermal elements Where the existing walls, roof, floor, windows or doors is to be retained and become part of the thermal envelope or renovated or subject to a material change of use and are un- insulated below the threshold values in column (a) of table below then the thermal elements should be thermally renovated/upgraded to the U values in column (b) in table below. (Note: this only applies where the area to be renovated is more than 50% of the surface area of the individual element and 25% of the total building envelope, and is technically and functionally feasible with a simple payback of 15 years +), as follows: Table 26: Renovation/upgrading of existing thermal elements Element (a) Threshold U-valueW/m 2.K Cavity walls (where suitable for filling with 0.7 insulation) Solid walls 0.7 Floors 0.7 Pitched roof- insulation at ceiling level 0.35 Pitched roof- insulation between rafters 0.35 Flat roof or roof with integral insulation 0.35 (b) Upgraded U-valueW/m 2.K * 0.25** * Lesser standard acceptable where reduces floor area by 5% ** Lesser standard acceptable where new work would effects existing-adjoining floor levels. Note: Insulation details and method of upgrading existing thermal elements to be agreed with the building control surveyor before works commence Payback report Building control can provide a payback report for the renovation/ upgrading of thermal elements if required please contact Building Control on for further details

56 Energy efficient lighting Fixed internal lighting fixed internal energy efficient lighting in new extensions must not be less than 75% of all the fixed low energy light fittings (fixed lights or lighting units) in the main dwelling spaces (excluding cupboards & storage areas), fitted with lamps which must have a luminous efficiency greater than 40 lumens per circuit-watt and a total output greater than 400 lamp lumens Fixed external lighting Fixed external energy efficient lighting in new extensions must consisting of either; (i) Lamp capacity not greater than 100 lamp-watts per light fitting and fitted with automatic switch off between dawn and dusk and when lit area becomes unoccupied; or (ii)lamp efficacy greater than 45 lumens per circuit-watt; and fitted with automatic switch off between dawn and fitted with manual controls. Consequential improvements (applies to existing buildings with a total useful floor area over 1,000m 2 ) Consequential improvements (additional work) are required to make an existing building more energy efficient which has a total useful floor area exceeding 1,000m 2 and is subject to an extension or provision of fixed building service in compliance with paragraphs of ADL1B & section 6 of ADL2B Commissioning of fixed building services Copy of commissioning certificate for fixed building services is to be sent to Building control within 5 days of completion of the commissioning work being carried out (or within 30 days for works commissioned by a person registered with a competent persons scheme) Providing information -building log book Log book containing the following information is to be provided in the dwelling on completion: Operating & maintenance instructions for fixed building services Instructions how to make adjustments to timing and temperature control settings etc Instructions on routine maintenance requirements for fixed building services in compliance with manufacturers details

57 Part N: Safety glazing, opening & cleaning Safety glass and glazing Doors and adjacent sidelights/windows in critical locations within 1500mm of ground and floor level, and 300mm of doors and windows within 800mm of floor/ground to be safety glazed to: BS EN 12150, BS EN 14179, BS EN 14449, which supersedes BS 6206 in compliance with the following diagram: Diagram 18: Glazing in windows, partitions, doors, side panels/screens & walls Safety glazing must comply with the new system of marking which requires visible and clear and indelible markings on each piece of safety glazing within critical locations in compliance with: BS EN 12150, BS EN 14179, BS EN

58 Part P: Electrical safety Electrical Installations New or works to existing electrical circuits or systems must be designed, installed, tested and certified to BS 7671 or with the current editions of the IEE regulations by a competent person in compliance with Approved Document P of the Building Regulations. A competent electrician or a member of a competent person scheme must test and certify all such works. The electrician must provide signed copies of an electrical installation certificate conforming to BS 7671 for the owner of the property and a copy must be forwarded to the Building Control surveyor for approval at completion, so the Building Control completion certificate can be issued. All switches and sockets including the consumer unit, ventilation & service controls etc, should be fixed between mm above floor level. Accessible consumer units should be fitted with a child proof cover or installed in a lockable cupboard

59 External works- paths, drives, patio & gardens New external paths to be shuttered 100mm thick conc. Mix type PAV 1, max bay size 6m with bitumen impregnated fiber board isolated Joints to BS 8110/5328. New tarmac areas to be rolled 20mm base course of coated macadam with 6mm textured bitumen macadam wearing course with concrete edgings, to BS4987. New 60mm pre-cast self draining concrete block paving to clients choice, laid in compliance with manufacturers details, to BS6717. Concrete/natural stone slabs to clients choice, laid in compliance with manufacturers details to BS 7263:1 Drainage of paved areas to be carried out in accordance with BS 6367:1983 A1 84 and Approved Document H. Paths and paved areas to have a non slip finish with a fall of 1:80 and a reverse gradient of at least 500mm away from walls of building. Surface water to be disposed of by an adequately sized and roddable drainage system via soakaways, or other approved means

60 Materials and workmanship All materials must comply with the following: British Standards or European Standards Product Certification Schemes (Kite marks) Quality Assurance Schemes British Board of Agreement Certificates (BBA) Construction Product Directives (CE Marks) Local Authority National Type Approvals (System Approval Certification) All materials must be fixed in strict accordance with manufacturers printed details and workmanship must be in strict accordance with BS 8000: Workmanship on Building Sites: Parts: 1 to 16. Where materials, products and workmanship are not fully specified or described, they are to be: Suitable for the purpose stated or inferred & In accordance with recognized good practice Guidance notes copy right Guidance notes copy right & produced by: Tony Gwynne, Forest of Dean District Council, Council Offices, High Street, Coleford, GL16 8HG. Tel: , Website: E mail: building.control@fdean.gov.uk Acknowledgements: Front cover illustration by Apex Architecture Consultancy: Information for domestic sprinklers by Nationwide Fire Sprinklers Ltd: Important note: It should be made clear that whilst every care has been taken to in compiling this publication, and the statements it contains, no party or individual involved in this publication can accept any responsibilities for any inaccuracies. Additional building control services we can provide Building control can now provide the following services and manage them through your project as part of the service we offer: o SAP Calculations: Design Stage Calculations includes Residential Energy Performance Certificate and registration of certificate on completion. o Air Leakage Testing ( Residential & commercial) o SBEM Calculations o Code for Sustainable Homes Assessments o Renewable Energy Evaluations/Payback Reports etc o Fire Risk Assessments For more information, please contact Tony Gwynne, Mark Saunders or Simon Drake on

61 For further advice on Building Regulation issues in Gloucestershire please contact your local Building Control Service: Cheltenham and Tewkesbury Building Control Service Cheltenham Office: Municipal Offices, Promenade, Cheltenham, GL50 9SA Tel: Fax: Cotswold District Council Building Control, Trinity Road, Cirencester, GL7 1PX Tel: Fax: Forest of Dean District Council Building Control Services, Council Offices, High Street, Coleford, GL16 8HG Tel: Fax: Gloucester City Council Building Control, 4 th Floor, Herbert Warehouse, The Docks, Gloucester, GL1 2EQ Tel: Fax: buildingcontrol@gloucester.gov.uk Stroud District Council Building Control Services, Ebley Mill, Westward Road, Stroud, GL5 4UB Tel: Fax: building.control@stroud.gov.uk Useful numbers of other agencies or companies Forestry Commission Sewage & Water Suppliers: Severn Trent Water Welsh Water/Dwr Cymru Environment Agency Emergency Pollution Hot Line Transco Gas Emergencies Health & Safety Executive Gloucestershire County Council General Enquiries Gloucestershire Fire & Rescue Service Highways Agency (Amended Oct Tony Gwynne)