Low Carbon Retrofit - Commercial Sector Thursday 15 th September 2011 Julie Godefroy, Hoare Lea
Contents Challenges and Approaches Can BREEAM help? Case Studies
Challenges and Approaches
What do we want? A space that better meets the client s needs: Function Comfort (noise; temperature; daylight ) Modern standards Carbon saving measures likely to be part of the outcomes, but not the main goal
Challenges and Approaches Assessing and Limiting Heritage Impact Negotiating Approvals English Heritage, Building Controls, Planners Improving Sustainability Performance Challenging the Brief
Where do we start? Site visits Occupant feedback Energy bills (if we have them) Cibse Guide F and other industry benchmarks DECs Building A
Internal Conditions Client expectations vsbuilding Constraints and Conservation purposes
Visualisation to support the design and heritage impact assessments
Lighting
Lighting Roman Baths Client: Bath & North East Somerset Council Emphasis on architectural features as well as bath, steam and bubbles Substantial energy efficiency improvements: Specially created LED spotlights with colour temperature and rendering to complement the stone Metal halide projectors
Embodied Carbon Is it worth it?
Embodied Carbon Carbon payback, in years Double-glazed windows Cavity wall insulation
Can BREEAM Help?
Using BREEAM for what we want BREEAM 2008 : BREEAM 2011: Post Construction Review Post Construction Review Credits for Post-Occupancy Evaluation BREEAM Refurbishment?
BREEAM 2008 -Where refurbishment scores well Re-use of Land Re-use of Structure Re-use of Façade Materials, as re-use in situ is rewarded In heritage properties Natural materials Timber A/A+ UK-sourced But Evidence of Green Guide rating and responsible sourcing chain of custody?
BREEAM 2008 -What can be difficult with (listed) refurbishments Energy performance Reaching Excellent would require whole new services Possibly low and zero carbon source e.g. connection to district CHP Anything that takes space eg plant; meters Anything visible eg lighting Materials suitable for conservation may not be Green Guide rated materials Daylight, view out, natural ventilation openings: may be good, but otherwise difficult to alter
BREEAM Refurbishment Domestic Due for launch 31st October 2011 Non-Domestic Pilot schemes from late 2011, Launch due in Summer 2012 Key difference with ratings for new construction : Intends to measure improvement as well as absolute performance Intends to be green deal ready
BREEAM Refurbishment Key issues Moving towards an 80% CO2 reduction (in line with government targets to 2050) Impacts on overheating and health Flood resilience Embodied impacts of materials Recycling of refurbishment waste Water efficiency Health, security and fire Good project management and design
BREEAM Refurbishment Comparison with BREEAM New Construction and Code BREEAM New Construction / Code BREEAM Refurbishment Energy Improvement on Part L 2010 Improvement over baseline Water Water efficient appliances, water consumption in m3/p/d Materials Green Guide rating of new elements Ecology Site + Reward for materials reused in situ Protecting and improving ecology Careful site selection and flood risk assessment Improvement over prerefurbishment (based on survey) Similar, but with reward for improving existing elements Similar, but only applicable to large-scale projects Retrofit for flood resilience
Case Studies
Case study: North Wales Police HQ Overview
Case study: North Wales Police HQ NWP HQ was chosen as a case study for the Carbon Trust Low Carbon Building Accelerator (LCBA) Programme Carbon Trust provide support and monitor projects Carbon Trust North Wales Police Environ Project Manager Hoare Lea Technical Support Design Team Contractor
Case study: North Wales Police HQ Key Goals Improving occupant satisfaction Improving thermal comfort (summer and winter) Reducing CO2 emissions: client target of 20% (design team aspiration of 30%)
Case study: North Wales Police HQ Occupant Satisfaction
Case study: North Wales Police HQ Energy Improvements Fabric 1. Insulation - external walls and roof; Insulated panels 3. New windows 4. Air tightness 5. Light shelves 7. Night-time cooling through automated window actuators Services 8. Radiators with TRVs, zoning with variable volume Control 10. Low energy lighting with daylight dimming and PIR controls Monitoring 11. 6 gas meters, 9 heat meters and 68 electricity meters 12. Internal temperature sensors and weather station
Case study: North Wales Police HQ Energy Improvements GAS ELECTRICITY 9% 24% Guide F TYPICAL Guide F GOOD PRE REFURB POST REFURB Guide F TYPICAL Guide F GOOD Improvements in heating systems and metering still expected User has targets and a monitoring programme in place PRE REFURB POST REFURB
Case study: North Wales Police HQ Comfort Pre-Refurbishment Temperature in Room 201 (Corner room, North and West facing)
Case study: North Wales Police HQ Comfort Pre-Refurbishment Room 218 (South) Room 213 (North) Orientation matters Controlling solar gains would be useful
Case study: North Wales Police HQ Addressing summer comfort - Reduce glazed areas on the facades - Install external solar shading on the east, west and south facades - Replace existing glazing with solar control (low g-value) units - Implementhigh level automated window panesto enable out of hour ventilation - Install low energy lighting linked to daylight control Key decision by user: Improve summer comfort without air-conditioning
Case study: North Wales Police HQ Comfort Post-Refurbishment Temperature between May and October 2010 Room 215-POST Refurb 28 o C 25 o C
Case study: North Wales Police HQ Comfort Post-Refurbishment South-East rooms: Similar days in 2006 and 2010 Room 215-POST Refurb Room 218-PRE Refurb
Case study: North Wales Police HQ Brise Soleils and Light Shelves
Case study: North Wales Police HQ Brise Soleils and Light Shelves Detailed Design 3 2 1 Light Shelf Brise- Soleil
Case study: North Wales Police HQ Occupant Satisfaction
Case study: North Wales Police HQ Summary of outcomes Considerable reductions in the building s energy consumption (~18%) and carbon dioxide emissions (~22%) Extensive energy monitoring system 10% Year-on-year target energy saving Summer overheating and winter temperature fluctuations significantly reduced with the building users noting a distinct improvement Substantial improvement in overall occupant satisfaction
Case study: North Wales Police HQ Lessons Learnt Clients brief must include Carbon Issues Stakeholder and design team buy in Communication with Building Users is Essential Reductions in energy consumption can be obtained without being detrimental to the user comfort. Even when faced with significant challenges and setbacks, the reasons for the successful implementation of the project is due to the Service Provider remaining steadfast in achieving the goals set out at feasibility stage Full commissioning is essential prior to practical completion
Case study: Somerset House East Wing Client: King s College Architect: BDP MEP: Hoare Lea Heritage: Alan Baxter Grade I* listed BREEAM 2008 Excellent a Client requirement Highly bespoke solutions, close cooperation with Heritage Specialist and Architect
Case study: Somerset House East Wing Historic Significance
Case study: Somerset House East Wing What was good to start with: Wall thickness insulation and thermal mass Floor to ceiling heights Proportions of glazing Central London location Main building elements to be retained What was a challenge: Lead roof: un-insulated and creating overheating risk on top floor Noise (fountains on central square) how to ventilate the rooms? Occupant density
Case study: Somerset House East Wing Innovative Comfort Solutions Detailed discussions with client on suitable comfort criteria Removable solar control film on West façade Using chimneys for ventilation air Phase Change Materials plasterboard to top floor
Case study: Somerset House East Wing Innovative Comfort Solutions
Case study: Somerset House East Wing CO 2 / Energy Study by Heritage Specialist on energy efficiency improvements Improved insulation levels, air tightness and thermal bridging Ground floor slab: excavation of 450mm, damp-proof membrane and floor re-instatement Roof : wood fibre insulation, breathable, made from saw mill off-cuts New double-glazed windows in central rooflights Services: New lighting, central plant for cooling and heating, including planned Combined Heat and Power Metering difficult due to lack of space With CHP, EPC rating of B
Case study: Somerset House East Wing
Case study: 8 Storey s Gate BREEAM 2008 Excellent a Client requirement (Institution for Civil Engineers) Grade II listed (part) Client: ICE Architect: Black Architecture Added roof and external wall insulation New double-glazed timber frame sash windows New services, with displacement ventilation and chilled beams Ecological improvements
Case study: Gower Street, UCL Student Union BREEAM 2008 Very Good Client: UCL Architect: Levitt Bernstein Grade II listed and in the Bloomsbury Conservation area of the London Borough of Camden Connection to the existing UCL district Combined Heat and Power scheme
Existing Estates Carbon Trading 30,000,000 Existing dwellings kgco 2/year 25,000,000 20,000,000 15,000,000 31% New dwellings 10,000,000 5,000,000 0 SCENARIO 1 SCENARIO 2 Scenario 1: 300 Existing buildings + 100 New Code 4 homes Scenario 2: 300 Refurbished buildings + 100 New Code 3 homes