This is a new house on a small infill plot in London, designed by Tectonics Architects. It is one of the first certified Passivhaus dwellings in the South East; we provided Certified Passivhaus Designer services to the design team.
We have worked closely with Tectonics to ensure that the stringent Passivhaus design targets for annual heating demand, primary energy use and very low air leakage are achieved.
A Passivhaus relies for most of its heating on its inhabitants, their appliances and sunlight. This was a challenge for this house as it is shaded by large Victorian villas to the south, and for town planning reasons the lowest floor is partly below ground. Nonetheless, this constraint was overcome with most windows facing west to receive sunlight during the afternoons. External blinds prevent overheating.
The contemporary design approach uses insitu reinforced concrete for the lower ground floor walls and floor, which are insulated with 250mm to 300mm of polystyrene. The upper floor is constructed using cross laminated timber panels, prefabricated off site, and insulated with 315mm of vapour open wood fibre insulation. Triple glazed windows, a highly insulated front door and an efficient ventilation system with heat recovery complete the energy saving approach.
Using the Passivhaus Planning Package (PHPP) energy calculation software, we ensured that a comfortable home would be achieved with heating costs of less than £18 per month.