Westcott House, a large Victorian country residence within Dartmoor National Park, has become the first building in the UK to be certified under the Passivhaus Institute’s (PHI) Low Energy Building Standard.

The new standard is designed to acknowledge projects which have overcome contextual and constructional challenges to achieve some of the highest standards of low energy design in the world.
Gale & Snowden applied a holistic passive design strategy to the renovation and extension of the house which allowed the existing property to be upgraded to a level of efficiency such that a conventional heating system will only be required in times of extreme winter conditions.  At the same time, summertime overheating is avoided and overall environmental impact is minimised.

Extremely high levels of insulation have been added to the existing building, both externally and, where existing stone facing was to be retained, internally, together with high-performance, triple glazed windows and doors.  Rigorous detailing was required to ensure continuity of insulation and airtightness around the building to reduce heat loss and minimise thermal bridging. 
The fabric-first approach was combined with a highly efficient mechanical ventilation system with heat recovery to ensure excellent indoor air quality and minimise heat losses through infiltration.  Low carbon technologies and on-site renewables further contribute to reducing the building’s overall carbon footprint.

Further information about Westcott House can be found here