Responsibly Sourced Construction Materials for Lucas Rd Housing

Client: Contour Housing Group Ltd
Contractor: Rowlinson Construction
Completed: June 2010

HOUSING – LUCAS ROAD, FARNWORTH

Development of 8 no houses in south Bolton (2 no terrace of 3 houses, and 2 no semi-detached houses) designed to meet HCA requirements, Lifetime Homes standards and Secured by Design.

The highly insulated timber frame created an air tight envelope reducing unwanted air leakage and heat loss resulting in a 25% reduction in carbon emissions. Daylight levels to all rooms are above average to enhance occupant health and well being but also to reduce the need for artificial lighting. The low energy light fittings provided internally and externally, along with the rotary dryers in the gardens further contribute to these energy reductions.

Transport emissions have been minimised through provision of secure, weatherproof cycle stores and home office facilities such that residents can work from home. The internal potable water is reduced to standards associated with Level 5 of the Code through careful specification and rainwater harvesting. The rainwater tanks supply the dual flush WCs and also have an external tap for garden irrigation. The Green Guide to Specification awarded A-ratings to each of the main building elements and all of the construction materials were responsibly sourced.

Ground Floor 0.15W/m2K:
40mm Gyvlon screed on 110mm foil faced insulation on visqueen DPM on 150mm deep precast concrete beam and block floor.

External Walls 0.17W/m2K:
140mm timber frame with phenolic foam insulation between studs, 50mm cavity, 102.5mm facing brick, internal plasterboard finish on softwood battens and insulation between.

Roof 0.11W/m2K:
400mm mineral wool quilt insulation in 2 no layers with the first laid between the joists and the second at 90˚ to the first.

Windows 1.41W/m2K:
Double glazed (16mm gap), low emissivity uPVC windows.

y Value 0.08W/m2K:
This thermal bridging value results from the use of Accredited Construction Details which minimise air leakage.

Air Permeability 4.44m3/hm2:
The design air permeability rate of 6m3/h/m2 was significantly exceeded proving the building envelope to be air tight.

Heat Loss Parameter:
0.91W/m2K

Space Heating & Hot Water
Condensing combi gas boiler – Baxi platinum 24 HE A with time and temperature zone controls.

MVHR:
Vent Axia Sentinel Kinetic (0.72 Watts/litre/second, 92% heat recovery efficiency).

Surface Water Run Off 0m2 impermeable area pre-development, 500m2 post:
Rainwater harvesting (1600 litre tank) collects 50% roof area run-off which is reused to flush the WCs. Attenuation accommodates the remaining peak run off.

Conclusion:
By the careful specification of appropriate materials and consideration to passive design a cost effective solution has been achieved without expensive ‘add-ons’ or requiring resident or landlord involvement and maintenance.