Postbridge Cottage

Building Excellence Certificate of Recognition 2021

Half a mile from the tiny village of Postbridge, set amongst bleak moorland, lay a desolate and derelict ancient farmers cottage. Remote the building may have been, but it's granite walls were strong, and the views were to die for. It was destined by the Duchy of Cornwall for transformation into a cutting-edge, super energy-efficient Passivhaus, styled sleekly to attract a new, discerning tenant.

Passivhaus design concentrates on super insulation, airtightness and use of passive solar gain to cut a building's space heating needs by up to 90% compared to the average UK building. The construction techniques required to meet the insulation and airtightness standards are demanding. It was enlightening for us to realise the capabilities of insulation, which far surpass those required by usual Building Regulations.

RM Builders and Contractors Ltd were selected by the Duchy to convert the property and it's attached barn to strict and rigorous Passivhaus standards, yet maintain the charming rustic character of this Dartmoor treasure. It was our first ever Passivhaus build, and very exciting for us. We learnt fast, and soon became fascinated by the technology enabling the extreme energy efficiency of Passive Houses.

Beyond the Passivhaus standards, the Duchy were keen to keep the feel of a traditional cottage, seeing us install water supply fed from a borehole in the back garden, and a woodburner for Dartmoor winters when solar power just can't quite cut it. The project was a huge success, culminating in achieving the official Passivhaus EnerPHit Certification, and, as an unexpected bonus, the Building Excellence Certificate of Recognition 2021 from Devon Building Control.