Federation of Master Builders – UK National Sustainability Award 2025 – Winner
This private residence in Sutherland, Scotland, presented a unique structural engineering challenge due to its location within a protected coastal area of special scientific interest. The remote nature of the site, approximately two kilometres from the nearest road, significantly influenced both construction logistics and material choices.
The structural approach relied predominantly on timber and Glulam, with the above-ground structure assembled from prefabricated cassettes. This method reduced on-site waste and minimised environmental disturbance. Given the site’s ecological sensitivity, conventional concrete and chemical-based materials were not an option for the access road. Instead, the driveway was constructed using gravel and self-stabilisation techniques to maintain a minimal footprint.
The house has been built according to Passivhaus principles, including high insulation standards and a thorough carbon assessment. The most significant structural challenge was the foundation design. The close proximity to the sea and the delicate nature of the surrounding ecosystem meant that traditional in-situ concrete foundations were unsuitable. To avoid contamination risks such as leaching into the water table, the foundations were prefabricated off-site and carefully positioned on-site. This approach required meticulous planning to ensure stability while minimising excavation.
Due to the presence of rock just beneath the surface, the foundation system relied on small, strategically placed pads instead of the typical deep trenches. These pads were driven into the rock, ensuring a stable base that met all structural and safety regulations. This method avoided extensive excavation, which would have been both time-consuming and environmentally disruptive.
Another notable challenge involved the internal plywood lining specified by the architects. This material limited the number of fixings that could be used, making it difficult to achieve the usual structural rigidity. The engineering team had to develop alternative stabilisation methods, including double walls and sharp angles, to compensate for these constraints while maintaining the design’s aesthetic integrity.
Spey Building, the project’s contractor, executed the complex requirements with precision, particularly in handling the off-site concrete work and road construction. The result is a highly efficient, environmentally sensitive home that blends seamlessly with its natural surroundings while overcoming significant structural and logistical challenges. Taigh Na Coille stands as an exemplar of thoughtful, sustainable engineering in a delicate landscape.
