Enerphit is the Passivhaus standard for retrofitting existing buildings.
Enerphit makes sense when you are doing a major renovation, as a deep retrofit is required to install the energy saving measures required. The energy demand target depends on the location – London is classified as a warm temperate climate, with the heating demand target of 20 kilowatt hours per square metre per year. [kWh/(m²yr)] More typically northern climates are classified as cool temperate requiring heating demand of 25 kWh/(m²yr). The predicted heating demand of this project is 13 kWh/(m²yr), representing a 96% energy saving from the as-found situation.
For this current Victorian terrace house project in London E15, we are the architects and passivhaus consultant. It is being done in two phases – with Phase 1 now complete.
The entire Phase 2 project is modelled in PHPP, with Passivhaus Enerphit pre-certification achieved at the completion of Phase 1. Phase one works included external wall insulation EWI, mechanical ventilation heat recovery MVHR, new triple glazed windows, and air tightness measures.
An insulated enclosure has been built in the attic for the MVHR to be within the thermal envelope of the house.
The Phase 2 works will include a rear ground floor extension incorporating the family kitchen diner with excellent access to the garden, along with a bathroom and WC in the centre of the house, and the floor will be lifted and insulated. Further information on ‘staged retrofit’.
SITE PROGRESS
Phase 1 of the project is now complete. The next steps will be to install Air Source Heat Pump, and construct the rear extension.
- Mechanical Ventilation Heat Recovery: Williams Energy Design, with Mango Projects for installation.
- External Wall Insulation: Pyramid Solution South East Ltd
- General contractor: Monogreen Renovation
- Windows: Citi Homes Windows, Rationel windows
- Passivhaus Certification: Zero Energy + Passivhaus
- Architects & Passivhaus Consultant: Cayford
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