One of the stipulations that Thomas and Sally Beevor, custodians of the Hargham Estate in Norfolk, made to their architect when they embarked on building their own home, was that it should use as much timber as possible from the estate mill.

Their clear and simple brief to Neil Winder of studioMGM was for a house they could retire to, on the estate. They also wanted a master bedroom downstairs, and the house was to address the couple's environmental concerns.

Winder responded with a relatively traditionally-styled eco-cottage that is constructed from, and clad in, timber. The design effortlessly mixes the old and the new, creating something that is truly beautiful and sympathetic to its surroundings – something Winder believes should concern more architects.

Use of a small construction team on site helped to deliver workmanship of a high quality and meant that minor design changes and developments could be accommodated with the minimum of fuss. “The whole structure was built using just three carpenters who worked with little more than saws, hammers and nails,” said Winder. Indeed, it appears that this is one of those rare construction projects where everyone involved took something positive away from the experience.

The traditionally-styled house successfully combines the old with the new

For Winder, addressing sustainability was a two-sided issue – the buildings he designs must both mitigate against today’s challenges and be adaptable to meet those that he is certain we will face in the future.

This project was in the luxurious position of having locally-grown and converted timber available for use – the timber is not certified, but there is certainty over its origins and sustainability. Only the timber for the windows was imported and, with the benefit of hindsight, Winder wishes that they'd all been a bit braver and used the estate sawmill for everything.

The foundation system of concrete pads with steel posts and ring beam is not only low cost but also low earth intervention and quick to assemble. In addition, it raises the building structure off the ground, provides better views from inside the property and, more importantly, allows planting right up to the perimeter of the house, which helps keep it cool in the summer and provides a buffer zone against the worst of winter weather.

Plants provide a buffer zone against the worst of winter weather

The house is constructed using an innovative twin-leaf timber frame wall system that eliminates the use of OSB to provide racking resistance. The construction uses an outer structural leaf and an inner non-structural leaf. The two leaves are linked and braced using a small number of diagonal solid timber members. The diagonal bracing and 15mm bitumen-impregnated softboard sheathing provide the building with all necessary racking resistance and reduce to an absolute minimum the amount of cold bridging in the frame. The softboard sheathing also makes a small positive contribution to the thermal performance of the overall envelope.

The decision to make only one of the two leaves from structural timber was taken because of concerns that the estate sawmill would not be able to produce enough graded structural timber. Producing any graded timber at all was a new challenge for the mill and one that mill manager David Elvin rose to by quickly appreciating the principles of structural timber grading and pre-selecting both logs and sawn timber for the grader sub-contracted from a local timber merchant. These additional steps helped to improve the yield of structural timber from the sawlogs and reduce the amount rejected by the grader to an absolute minimum.

Exposed beams provide a rustic yet contemporary look

A constraint to the project was the fact that the sawmill could only produce timber up to a maximum length of just over 5m. As a result, all of the principal members were constructed from multiple pieces of timber bolted together at 600mm centres.

The house is clad with locally-grown unseasoned European larch, 150x19mm and fixed with a single large head galvanised nail at each batten position. The boards are predominantly heartwood only but Winder admits that the odd bit of sapwood will have got through the selection process, as they were keen to minimise wastage and keep construction moving – total time from woodland to site was around 10 days.

The single fixing, which, crucially, goes straight into the batten rather than into the adjacent feather-edged board, allows for movement as timber moisture content changes with the seasons. The corner cover pieces are screw fixed and designed to be removed and reinstated should any of the feather-edged boards need to be replaced or adjusted.

The house is clad with locally-grown unseasoned European larch

Three years after completion Winder is pleased with how the building has performed and matured. The planting, largely in native species, has developed as he had hoped, to the extent that it now both shelters and shades the building from the best and worst of the weather.

Given a second attempt, Winder probably wouldn't change very much at all – and nor would Sally and Thomas Beevor.

•The Old Woodyard forms part of a new collection of case studies to be launched on the TRADA website in October. Visit www.trada.co.uk