Description:

The Wedge Pavilion at Summerhill Farm in Papamoa is a demonstration of what is possible through the marriage of centuries old traditional carpentry practice and modern-day digital fabrication technology. Adapting traditional wedged joints, combined with possibilities of three-axis CNC fabrication, the project developed a construction system that enables the use of low quality timber to produce a sophisticated timber structure.

The use of a system of wedged joints allowed the structure to be assembled without requiring the timber to be especially stable or a high degree of accuracy in fabrication. The wedges ensure that each joint can be fixed together tightly to produce a strong joint, and can be adjusted and re-tightened as the timber continues to shift and settle over time. By using CNC milling for the fabrication of the structure, hundreds of complex parts, which otherwise would have been extremely arduous to produce, could be produced quickly without error.

Not only was a new structural system developed specifically for the pavilion, but the fabrication process itself also underwent a research and design process. When using automated fabrication technologies such as CNC milling, a key issue is that unlike a human carpenter the machine does not respond to the material it is working with, but only reads coordinates and tool paths pre-programmed in digital space. Any natural warping, bowing, or twisting of timber is not reflected in that digital space, potentially resulting in inaccurately fabricated parts. However, the joint system used for the Wedge Pavilion allows considerable adjustability in each joint— to seamlessly absorb inaccuracies or deformation—so that the joints can be tightened to ensure strong structural connections.

Built without the use of nails or screws (excluding the roof fixings), each post, beam, joist, and rafter connection was made using fully timber-to-timber wedged joints. This allowed it to be fully prefabricated, with a 100% test assembly carried out in the workshops. With the structure being located a 20-minute walk from the nearest road, it was also engineered to eliminate the need for concrete in the foundations.

The frame is a combination of redwood posts and beams, with harder cypress wedges. All the timber was grown on the farm where the building was constructed. As such, the embodied carbon of the pavilion is negative. The project was easily assembled, requiring little more than a mallet and a wrench, and without the need for a skilled builder or heavy equipment. What’s more, the elimination of permanent fixings also means that the pavilion can be easily deconstructed for relocation or recycling.

The Wedge Pavilion sits quietly next to a burbling stream in a bush filled valley. Functionally, it is very simple, serving as a resting place for cyclists and hikers on the farm’s network of mountain-bike and walking trails. However, the pavilion is really a suggestive space—seeking to question and advance the way we build.