This ‘extreme’ refurbishment was commissioned by a carbon consultant and his partner in 2008.  They wanted to transform a neglected Victorian terrace house into an urban idyll and at the same time see how far they could reduce the carbon emissions of such a property.  We developed an approach where the living, cooking and dining spaces were transformed by a modest extension at the rear over the lower two levels. A rooftop extension added a third bedroom-cum-study.

The house achieves an 80% reduction in CO2 emissions, primarily by incorporating high levels of insulation and achieving an air tightness of 1.1 ach @ 50 Pa, very close to the Enerfit .  Fresh air is supplied by an MVHR (mechanical ventilation heat recovery) system. A photovoltaic array on the roof with a 1000 kWh/a output provides a little over half the annual electricity requirement.  

The ‘feel’ of the house was as important to our clients as the technical issues and the interior spaces were developed very carefully with them throughout the process.  Many of the 1000+ people who have visited the home during open days have commented on the quality of light, sense of freshness and feeling of comfort.  Monitoring has shown the house to be remarkably stable over the seasonal cycle and energy consumption corresponds very closely to modelled predictions.  In 2010 the owner and Robert Prewett presented a paper on the project at the 14th International PassivHaus conference in Germany.