For Wales' first Passivhaus school the client's vision was to showcase homegrown timber and make it part of an inspiring space for pupils.

The project is a mix of refurbishment and new-build with the latter including the first Passivhaus school building in Wales, as well as an elliptical pod for multi-use purposes, which unites the new and old elements of the school. The original infant school has been rationalised and renovated, creating four large, secure, open-plan classrooms as well as multi-use space for teaching and messy play, breakout space, and covered outdoor areas.

The new-build aspects of the scheme demonstrate an exemplar use of Welsh timber, which the new buildings are entirely constructed from. In line with Passivhaus requirements, the new junior years building is wrapped in continuous air-tight duvet layer from the foundations-up. To give a fresh and natural aesthetic, the envelope is clad in Welsh larch and topped with a contemporary zinc standing seam roof.

The elliptical pod building, constructed using Brettstapel, is one of the first examples of this type of engineered timber construction being used in the education sector in the UK. The technique makes use of Wales’ abundance of low-grade softwood, Douglas Fir and Sitka Spruce.

The sustainable Passivhaus strategy that underpins the new extension's excellent building performance is met with an innovative low-carbon approach to design and construction. The Brettstapel system in particular is a great example of this, maximising the performance of low-grade softwood components allowing them to be used structurally whilst providing a natural, toxin-free interior that complements the interal air quality.

The Brettstapel process uses short lengths of softwood timber, held together with hardwood dowels that swell and tighten with exchanging moisture content. The result is a solid timber panel, providing a dual purposes as a load bearing wall or floor, and an exposed internal finish. In the case of the pod building, each panel forms a facet of the ellipse shape and provides a beautiful natural and healthy finish.

Renewable, low-tech construction techniques are utilised throughout the scheme in particular on the Welsh timber frame and façade. Besides the inherent excellent sustainable credentials, the two new buildings showcase the capabilities of Welsh timber and promote the material to the industry, with positive consequences to broaden the market for Welsh timber.

The eco-specification continues beyond the construction aspects of the scheme and is continued throughout the interior. Wood wool acoustic panels made from a mixture of pine, spruce and poplar wood fibre strands, bound with magnesite and treated with natural salt have been specified for the ceiling panels. Other materials have included recycled tyre matting in areas of heavy footfall and natural vegetable oil stains on interior ply finishes.