Touchwood Homes

Porters Passivhaus


This project was managed by David and Penny, a retired couple building in the garden of their existing home. The foundation, frame and Optiwin windows were supplied and fitted by Touchwood. The renewable heating system was designed and installed by our local partners Dragon Contracts, featuring a 1000 litre thermal store, 4 solar panel arrays, log boiler, underfloor heating loop, MVHR heater battery a 4kW PV array.


The home has near negative running costs – with Passivhaus levels of heat loss through the building structure (due to extreme air tightness, masses of insulation and high quality Aluminim clad Optiwin Passivhaus windows) on the coldest winter days a 3 hour burn on the log boiler is sufficient to maintain the entire home internal temperature at 19 degrees and provide all hot water demand for a 24 hour period – only using a minimal amount of locally sourced logs. On the occasional sunny winter day, the large solar array has been sufficient to charge the thermal store enough to negate the need for a boiler run for a few days – and of course in summer the home makes money from the PV array, aswell as the solar array providing all hot water provision and 4kWp PV array.

Vital Stats:

Final client managed build costs /m2 £996

PHPP calculated heating requirement (by Williams Energy): 14kWh/m2.

After being occupied for a year, the actual heating requirements have matched the PHPP calculated values nearly perfectly.

The client’s for the Porters project kept a blog during the build of their home, to view please visit: 

Diary of a self build

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