new build

about using timber frame for passive house, for example over the possible lack of thermal mass, but he’s now a convert. “I’m now sold hook, line and sinker on timber frame. It’s just so quick to put up. At Lancaster, we struggled all through the winter in the frost, rain and muck. Timber frame is so much more manageable, quicker and cleaner,” he says. Thermal mass has not proved to be a significant issue at the Cumbrian house – there is an insulated concrete slab under the reclaimed wooden floors, which provides mass. The wall system consisted of pre-constructed twin-stud panels, delivered to site to be taped then filled with pumped cellulose insulation. The panels support the roof, allowing continuity of insulation and rapid weather-tightness. The

frame was then sheathed with a rendered block wall around the ground floor and wooden cladding at first floor, both for aesthetic reasons and to create a clear cavity to ensure Cumbria’s driving rain does not get into the insulated fabric. The finished building is a neat, compact house with a simple form, that was cost-effective to build and is very easy to heat. “It’s very comfortable, we had to get used to the even temperatures everywhere. There is no fire to sit next to, but it is very, very nice. Especially in cold weather, it’s lovely — immediately you are in the warm. The indoor temperatures average around 21 or 22 degrees, and it has never gone below 18,” the client says. The very low heat load is evident: “It warms

up very quickly in response to the number of people here, or when we are cooking. It’s very efficient at keeping us warm.” Passive house is known for minimal heating systems, and this build was designed and built according to the classic approach of an electric heating element in the ventilation supply ducts. However, the occupants prefer to manage without any direct heating as far as possible. Instead, like all passive buildings the house makes good use of solar gains and internal gains from people and appliances, then on top of this there is an almost-all-renewable contribution from the giant 500 litre thermal store at the heart of the house. The thermal store – whose primary job is providing domestic hot water — receives most of its heat from renewables on the roof. u

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