Mosshayne Farmhouse

An Ultra Low Energy and Healthy Family Home in the East Devon Countryside

The historic Victorian farmhouse at Mosshayne Farm, built 170 years ago, had minimal insulation, coal-burning fireplaces, single glazed windows and high levels of cold air infiltration, resulting in a draughty, cold and very energy-inefficient building.

Gale & Snowden Architects has since worked with their clients to extensively renovate, refurbish, and extend the farmhouse, to create an energy-efficient, sustainable, healthy, contemporary and comfortable family home. Although much of the existing internal plan has been retained, the new house now revolves around a remodeled farmhouse kitchen, opened up to create a true hub for the family.

Newly formed openings in the south elevation house large sliding doors which lead directly to the garden, whilst flooding the kitchen and dining space with daylight. A new garden room provides an external dining and social area and encloses the rear garden space. Additional openings in the north elevation allow daylight into the building and visually balance the elevation.

Visitors are now greeted by a new entrance porch with its sweeping roof projection which stands in stark contrast to the traditional lines of the original farmhouse. The porch orientates the front of the house and provides a buffer space between the external environment and the internal thermal envelope.

Local craftspeople were employed for much of the internal work, including the painstaking renovation of existing timber window shutters, modified and supplemented to function with newly installed timber framed, triple glazed windows. An external wall insulation and mineral render system has been applied to the outside of the existing walls, significantly increasing thermal performance and minimising cold bridges.

Building materials and components have been carefully specified to meet the performance requirements of a low energy and healthy building. A fabric-first approach has minimised energy demand, which is now readily provided by a log-burning range stove with a back-boiler and thermal store. This feeds the domestic hot water, towel rails and small underfloor heating circuits. Solar thermal panels are also integrated into this system.

The recently completed works to the farmhouse mark the first phase in a series of development work planned for the farm, including a contemporary extension designed to meet the Passivhaus standard.

A summary of key environmental features is as follows:


  • External wall insulation with minimal thermal bridging, achieving a U-value of 0.2W/m2K
  • Additional loft insulation to 400-500mm thickness
  • High performance Passivhaus Certified timber triple glazing 
  • Increased passive solar gain via new south facing glazing
  • Natural materials - oak, slate, reused floor boards
  • Natural ventilation design, including use of the central stairwell to produce natural stack effect ventilation
  • Low/non-VOC, organic paints, stains and waxes
  • Radial wiring throughout and shielded cabling to reduce electromagnetic radiation
  • Easily cleanable surfaces to reduce dust-mite habitats
  • Avoidance of PVC-containing products
  • Log burning stove for renewable cooking and hot water


"We have been warm and comfortable over Christmas, and loving how the whole house can be warm from just one log burning cooker"