The opening last friday of the Retrofit for the Future 'Haringey PassivTerrace' by Anne Thorne Architects for Metropolitan Housing Partnership, construction by Sandwood Design & Build, was attended by local MP Lynne Featherstone, and Councillor John Bevan, Housing Association representatives, housebuilders and lots of architects!
The refurbishment works to 10 Hawthorn Road are to a very high energy standard, part of the ‘Retrofit for the Future’ programme, funded by the Technology Strategy Board to show how we can retrofit existing houses to achieve 80% reductions in CO2 emissions.
‘Passivhaus’ Principles Retrofit
We used Passivhaus design principles and components, concentrating on a 'Fabric First' approach with high levels of insulation and air-tightness to dramatically reduce the energy demand and CO2 emissions for this solid-walled terrace house.
The retrofitted house has been designed to consume over 80% less energy than the existing house, thereby reducing carbon emissions by 80%. We used the Passivhaus Planning Package (PHPP) to model the existing and potential heating needs and energy use of the house, to allow us to see the effect of small adjustments to the design of insulation, quality of windows, air-tightness, cold bridging, ventilation strategies and heating & hot water systems.
A Natural Approach
This retrofit uses insulation materials from renewable sources, such as sheepswool and woodfibre insulation, and natural mineral plasters such as lime plasters internally and clay aggregate for chimney void fills.
These materials are used for their hygroscopic/vapour-open qualities to help deal with moisture within the existing building fabric, and also reduce the embodied energy of the retrofit materials in the house, actually sequestering / locking carbon into the build (unlike other forms of building materials, such as phenolic foamed insulation, etc,).
Predicted Space Heat Demand = 31 kWh/sqm/yr
Predicted Heating Load = 16 W/sqm
Predicted Primary Energy Use = 91 kWh/sqm/yr
Target CO2 Emissions = 18 kg CO2/sqm/yr