BUILDING CONTROL GUIDANCE SHEET REPLACEMENT WINDOWS AND DOORS Last updated 16/11/2010

Transcription

1 Building Control Charnwood Borough Council Southfield Road Loughborough LE11 2TN BUILDING CONTROL GUIDANCE SHEET REPLACEMENT WINDOWS AND DOORS Last updated 16/11/2010 Page 1 of 6 PURPOSE: This Guidance Note is for the benefit of local architects, builders and the general public. Its purpose is to provide information, promote good practice and encourage consistency of interpretation for all. It is purely advisory in nature and does not cover every aspect of the topic concerned, but tries to cover the main, commonly encountered points. If more details are required then the relevant Approved Documents, British Standards or manufacturers instructions should be consulted. The Guidance Note is not intended to outline the only way of carrying out the type of work referred to. If in doubt, please contact your local Building Control Authority. This document should not be submitted as part of any Building Control application. The Council offers a complete Building Control service, from pre application advice on technical aspects and how to make an application, through to plan checking and an inspection regime to ensure a safe and compliant building. We also offer an Energy Performance Assessment service which uses SAP methodology to produce Energy Performance Certificates in respect of both new and existing dwellings. Please contact Building Control for any further information: Building Control Contact Details: General enquiries: Tel: (24 hour answer machine) Fax: building.control@charnwood.gov.uk Web: Further information can be obtained from The Building Regulations 2010 or from the Council s Building Control Service on request. The views expressed in this document are those of Charnwood Borough Council and do not necessarily represent a guaranteed methodology for compliance with the requirements of the Building Regulations Charnwood Borough Council accepts no liability for any claim that may arise in relation to reliance on the information contained in this document.

2 REPLACEMENT WINDOWS AND DOOR GUIDANCE FOR DWELLINGS 1.0 Introduction 1.1. This guidance note considers the replacement of windows and doors (those doors with more than 50% glazed area) in Dwellings only. From April 1 st 2002 the Government introduced the requirement that all replacement windows and doors complied with the Building Regulations and therefore became known as controlled services and fittings. 1.2 The regulations also apply to new windows and doors in dwellings and both new and replacement windows in non dwellings (e.g. shops, office, factory, schools, common areas of flats etc). This guidance sheet only cover replacement windows and doors in dwellings, for all other premises or installations, please call us to discuss; contact details are on the front cover. 1.3 Failure to comply with the regulations can lead to enforcement action and fines, for further details: rkrespbrfailure 1.4 Additionally, solicitors do specific checks when you sell or remortgage a property and this can mean sales/mortgage offers fall through! 2.0 How do I apply for building regulations? 2.1 Make a Building Regulations application you can submit a Building Notice application see our web site for further information or request an application form from Building Control. You must then complete the form, and return it to us together with the appropriate charge at least two working days before commencing works. 2.2 On receipt of the Building Notice, a Building Control Surveyor will normally visit your property twice - once before and once after the replacement windows are installed. When the works have been satisfactorily completed we will issue a Completion Certificate and you are advised to ensure the certificate has been issued before making the installers final payment (ensure you agree this first however at the signing of the contract stage) Forms are available at: contact details are on the front cover should you not be a computer user. 3.0 Alternative to using Building Control (specific limitations) 3.1. Alternatively you can use a company registered on the Governments competent person scheme, hemes/existingcompetentperson/ 3.2. Once the work is completed the company then register within 30 days, the completion certificate with the Local Authority. A copy of this should be retained by the owner. 2

3 4.0 Historic buildings/conservation area 4.1. Planning permission or listed building consent may also be required, please contact: or call (main reception) 4.2. If you wish to replace historic windows there is a possible exemption from the thermal requirements but this needs to be supported by the Conservation Officer in agreement with Building Control. Please contact us to discuss further specific requirements 5.0 Houses of Multiple Occupation (HMO s): we suggest you speak additionally to Private Sector Housing: or What regulations do I need to consider? 6.1. Thermal insulation: Replacement windows must comply with minimum standards of thermal insulation - for window frames this is a maximum U-value of 1.6W/m2K, whilst for doors a maximum U-value of 1.8W/m2K is required. Window energy rating C or better (WER) Please note that standard double glazed units do not meet these requirements, manufacturers details will be required Please make sure when ordering your windows that your supplier can prove the glazing units will satisfy these requirements, as the Building Control Surveyor will need to see this proof before issuing a Completion Certificate. 7.0 Structural safety: If the replacement windows are wider than those they replace, or involve the replacement of bay windows, then the Building Control Surveyor will need to be satisfied that proper structural support is provided above the window and in bays that the support corner posts are adequate In many older buildings, the timber frame of the window was often sufficiently strong to carry the load of a wall or roof above it without a lintel. Obviously in these cases either a lintel needs to be installed when the window is replaced, or the new frame carefully reinforced to carry the load NOTE: If this structural work is required, it is not just a replacement of window, therefore an additional application is required for this structural alteration, please speak to us for advice. This type of work can only be controlled by a Building Control body. 8.0 Safety Glazing: Low level glazing areas within 800mm of floor level, glazing in doors and within 300mm of door edges less than 1500mm above floor level should generally be of a type so that if broken, it will break safely. In practice this means such glazing should be either laminated or toughened. (See diagram1) Ordinary glazing can still be used in small pane sizes however, provided the glass is sufficiently strong to resist breakage. (Diagrams 2&3). Kite marks need to be clearly visible as per the British or European standard. 3

4 Diagram Means of escape: All first floor windows in dwellings should ideally have opening lights large enough to allow you to escape through them if you were to become trapped in the room by a fire or smoke This also applies to ground rooms where they do not open directly to outside air or into a hall leading to an external door through which you could escape (inner room) To meet this requirement all such windows should have an unobstructed openable area of at least 0.33m 2 and be not less than 450mm high and 450mm wide (the route through the window may be at an angle rather than straight through) If your existing windows do not meet the above escape requirements, we would strongly recommend for your own safety, that you take the opportunity to provide them in the replacement windows. 4

5 9.3. This is not a however a requirement of the regulations, which simply state that the replacement windows must be no worse than those they replace in this respect Where the existing windows already have larger opening lights than the above requirements, those in the new windows can be reduced in size provided they are not reduced to less than the dimensions below. Windows (particularly top opening casements and roof windows) should be designed to remain open without needing to be held by a person making their escape. Diagram For example if a window has a clear opening of 450mm the other dimension would need to be 750mm. (0.45m x 0.75m = 0.33 metre square) Measurements are always to the opening area not the window cill, the shaded area in the diagram above Ventilation: The Building Regulations require that adequate ventilation be provided for people in buildings, so you must not worsen the existing rooms ventilation provisions. If your original windows have background trickle ventilation, then the replacements should also be fitted with them though you are recommended to have minimum 5000mm 2 trickle ventilation fitted anyway In addition all habitable rooms and rooms containing a W.C. should have opening lights of at least 1/20th of the floor area of the room which they serve. (WC s and Bathroom can omit this requirement if they have extract fans installed to approved document F) Where a habitable room (e.g. lounge, dining room, study etc) leads into another room or conservatory to get is background ventilation, 8000mm 2 background vent required to each room in addition to the purge ventilation calculated by reference to the Approved Document F using Appendix B 5

6 10.2. Where no ventilation opening existed, minimum opening lights sizes must be provided as follows: Habitable rooms at least 1/20th of the floor area of the room which they serve, if the window opens less than 30 degrees then 1/10 th of the floor area of the room and a background ventilation of 5000mm 2 equivalent area; Kitchens / utility rooms /bathrooms (with or without W.C.) background ventilation of 2500mm 2 equivalent area A trickle vent sometimes called a background vent should be 1.7m above floor level. A trickle vent allows fresh air flow at a controlled rate to enter with dwelling without wasting valuable heat and also due to their height above floor they generally will not create cold draughts to nearby people For kitchens, utility rooms and bathrooms an extract fan is also normally required, so if you are removing window fans these must also be reinstated. If electric, Part P of the regulations will apply Combustion air to fires and heating appliances: In some cases the existing windows may contain a permanent vent to supply combustion air to heating appliances, also you may find the removal of ill fitting windows which previously let air filter into the room could cause problems to your heating appliances If this is the case you should ensure that either the replacement window contains a similar permanent vent, or that some other means of providing the required ventilation is installed at the same time It is advisable to have your appliances checked out by a registered installer, See: hemes/existingcompetentperson/ 12.0 Retention of level thresholds: Many newer properties are now provided with level access thresholds and your new doors must not worsen this access, nor reduce the doors clear opening width Protection from falling: For opening windows less than 800mm above floor level where you can fall more than 600mm the openable window should be fitted with a restrictor to prevent children falling out this needs to be capable of being released in a fire situation - ask your installer for suitable guidance. These device are available inbuilt into the hinge or can be added separately Fire Resistant Cavity closers: Note - where wooden windows are replaced and there is a clear or partially filled cavity construction, you are required to provide suitable insulated half hour fire resistant cavity barriers to the perimeter of the wall cavity around the window on all four sides of the opening to prevent fire spread, if the dwelling has a fully filled cavity this will not apply, so why not have those clear cavities pumped full of insulation? 15.0 Fire resistant Glass: Some windows and/or doors have a fire resisting role, often but not always; Georgian wired glass, this can be adjacent to boundaries, adjacent to stairs or in garages or near to exit doors particularly in flats/apartments this is to prevent fire spread and/or protect an escape route, if in doubt ask! 6