special report: housing
15
Brise soleil solar shading system allows a combination of light and thermal reduction
runs below the concrete floor slabs creating an envelope of continuous insulation which min- imises heat loss. Having a design load of 130 kN/m2
and is highly durable with excellent
moisture-resistance and compressive strength, enabling the insulation to perform outside the waterproofing envelope. Installing insulation below the slab helps to avoid thermal bridges at floor and wall junctions and makes the most of precious internal space, meaning it is fast becom- ing recognised as an effective way of insulating new buildings. Dwelling forms have been kept deliberately
simple at the Hastoe development to avoid thermal bridging risks and porches, meter boxes and Brise Soleil are all independently supported to avoid penetrating the insulation overcoat. East- West orientation of the blocks facilitates passive solar gains with careful attention to shading to avoid summer overheating. The design and construction methods also
assisted the incredibly low air tightness require- ment of 0.6 air changes per hour, with internal wet plaster providing the majority of the barrier and all joins covered in specialist membranes or tapes. Specialist thermal modelling was undertaken
by Inbuilt to calculate thermal bridges and advise on the impact of small changes to the design. For example, the crucial impact of small changes to window designs was modelled in advance to help value-engineer the project and feed into the spec- ification of future sites. Everything was detailed at 1:2 in order to convey the importance of air tightness and to assist the accuracy of the Passivhaus Planning Package (PHPP) modelling. Design and build is one thing – the dwellings
also need to stand up to the rigours of everyday life. The choice of servicing strategy had to balance familiarity for residents, availability of components, client requirements and cost, and conventional gas boilers were eventually selected. These are being coupled to large thermal stores to prevent cycling and are supplemented by solar thermal systems. The thermal stores will supply domestic hot water as well as feeding top-up heat via a duct heater into the air supplied by a heat recovery vent- ilation system.
Key partners: Architect: Parsons & Whittley Main contractor: Bramall Construction Employer’s agent: Davis Langdon M&E consultant: Robinson Associates
Key products: Below-slab insulation: Dow Chemical Company Limited Roof insulation: Knauf Insulation Limited Windows: Internorm Edition MVHR units: SHS HeatRecovery Walls: Aircrete Blocks/Springvale Platinum EPS and BASF Aircrete Blocks: Thomas Armstrong
Floor 0.07 W/m2
Key facts and figures: U Values: Walls 0.088 W/m2 /k
/k Windows 0.79 W/m2 /k
MVHR efficiency: 92% Air Changes per Hour: 0.6 [n50]
Standard trussed rafter roofs supporting 500 mm of Crown loft roll
enq. 122
...searchable information archive at
www.adfonline.eu
Floormate insulation being installed to run under the reinforced concrete ground floor slab
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52