BRE Global, an independent third-party approvals company owned by the BRE Trust, has developed the new BREEAM standard for the sustainable housing sector aimed solely at the retrofit market. Within 26 million dwellings, Britain has the oldest housing stock in Europe. This makes the country’s housing, the biggest contributor to CO2 omissions. It is why the UK is committed to reducing the carbon footprint of 26 million homes by 80% by 2050.
Higgins’ refurbishment of a post-war semi-detached property for Greenfields Community Housing in November already achieved the outstanding level of the new BREEAM standard. Exactly like their latest CO2-reducing refurbishment of the Victorian property, it was achieved within a budget previously considered too low. The budgets of previous attempts by architects exceeded £150,000 per home.
“Our achievements added no more than £21,000 to the funding required by necessary Decent Homes improvements applied simultaneously,” said Higgins sustainability manager, Allan Ronald. “We have therefore exclusively proved the potential of BREEAM for properties at each end of the spectrum for age, and the potential to achieve such a high standard against more realistic budgets.”
Usually the biggest challenge to any refurbishment is airtightness, but an outstanding 50PA pressure and air loss of between 2.75m3/hr/m2 was achieved by the 10-week refurbishment for Swan Housing Group. This is an amazing technical result for British housing, and especially for such a complex layout that is typical of Victorian origin.
The 5-bedroom Victorian deconversion in Newham presented extra challenges because of its layout, by offering little roofspace facing the right south-east direction for solar renewables to generate electricity and to heat water.
To be expected from Victorian solid-wall construction, the 5-bedroom house’s insulation was poor requiring major improvements upon chilly average U-values of 2.6 W/m2K. The high expense of an initial preference for insulation slim enough to reduce the intrusion into floorspace was beaten by a Kingspan K18 specification.
The home improvements carried out to the Victorian end-terrace include:
- 400mm-deep blown cellulose Warmcel loft insulation to achieve 0.11W/m2K. Insulated lockable hatch.
- Overlay floor and party wall with Kingspan K18 insulation system to achieve U values of 0.22W/m2K.
- Upper floor’s boards lifted for installation of 100mm mineral wool insulation between joists. 400mm-deep blown cellulose Warmcel to insulate the ground floor.
- A-rated triple glazing in timber-frame windows with inert gas cavities to achieve U value of 0.8W/m2K.
- Doors replaced to achieve 1.0W/m2K with airtight seals.
- Baxi Solaflow solar thermal domestic hot water system.
- Baxi Ecogen micro-combined heat & power dual energy system, generating 1kW electricity while providing heating and hot water.
- Vent Axia HRE-350 ventilation installed to attic area with ducting, input and extract layout.
- Dual-flush cistern, spray-head taps and shower with restrictor to achieve under 110ltrs potable water per person per day.
- 200-litre water butt.
- Low energy light fittings throughout, to reduce the baseload by 40%.
- Airtight seals around all skirtings and junction of walls and ceiling at first floor level.
The project represents one of 15 refurbishment projects signed up to pilot BRE’s standard, eight of which are being carried out by social landlords. Comparing the new standard to the Code for Sustainable Homes for new build, BRE project manager Gavin Summerson said:
“A one-size-fits-all solution cannot work for existing homes because of the diversity of stock- different property types and ages. Some home-improvements investigated in trials were known to get 80 per cent cuts in carbon, but only actually meeting level one of the Code for Sustainable Homes because they were cutting from such an incredibly low starting point. There is no universal starting point, so it is about making the most of what you’ve got.”
Instead of using the fixed carbon-related goals associated with new-build standards, the new BREEAM standard will be measured based on the refurbishment itself. It will include new energy standards that recognise the varied baselines for existing homes. Overall, the standard is intended to focus on climate change adaptation, including resilience to flooding and overheating, as well as promoting the well-being of occupants.
The final standard is expected to launch this year, before the Green Deal kicks off in 2012. To reach the 2050 deadline however, 12,500 homes will need renovating every week. The government has plans to refurbish 7 million properties by 2020.
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