Despite its conventional appearance, this 12-dwelling residential development is an innovation for Britain. It achieves Code for Sustainable Homes Level 5 compliance, one of the first such traditional housing projects to do so. We worked with the architect-developer to facilitate this achievement within the constraints of a low-key aesthetic that was central to gaining planning consent.
The development consists of 10 semi-detached and two detached houses, all of which are two storeys plus usable loft space. To help meet the Code's requirement for net zero energy use for heating, we focused on the creation of a highly insulated, air tight building fabric. The buildings are constructed from Insulated Concrete Formwork (ICF) — prefabricated blocks comprising a 100mm concrete core sandwiched between 75mm layers of expanded polystyrene. Windows are triple glazed. Necessary ventilation is provided by a whole-house mechanical ventilation system located in the loft space and including a heat recovery system. The interiors are heated by underfloor pipes in a layer of thin screed.
To off-set energy usage, each house is provided with approximately 25 sq m of roof integrated PV tiles on the west and south faces. Rainwater harvesting is also integral. A buried 5,000 cubic litre tank collects water for use in washing machines and toilets.
We advised on sustainable sourcing as part of our overall contribution. All materials used are rated BRE Green Guide A or A+. The ICF was provided by Aggregate Industries — the first concrete supplier in the country to achieve BES 6001:2008 certification.
Following the success of the first 12 units, we are investigating the feasibility of achieving Code for Sustainable Homes Level 6 for a further two buildings on site.