Coppiced Timber Roof

In 2012. staff and students from the University of Brighton’s School of Architecture and Design experimented with coppiced timber as a roof structure for their Graduate Show.

Working with continuous lengths of timber, the project began by looking at exploiting the instability of green wood to coerce it into a particular radius whilst still flexible from being freshly cut. Green timber is relatively untested for use in construction, as most building and furniture projects prefer the stability of dried timber. Our pavilion’s final shape and design evolved in direct response to what was learnt in our experiments.

Over the Easter recess in 2012, a group of students and tutors spent a week in local woodlands working with David Saunders of the Woodland Enterprise Ltd. The exercise was to search for innovative ways to use UK timber species taken from local woodland managed by coppicing and to experiment with different methods of bending the freshly felled green timber. These included steaming over an open fire, sawed grooves and tensioning with weights.

Spring is the most promising time to work with green timber as the sap is rising in the trees and so the wood is at its most flexible. Spruce, larch and ash are wonderful timbers with good structural integrity, but our final choice was birch as it is considered a weed in the woodlands and has little value beyond firewood. We felled 100 trees to make space for the more desirable oak, and set to work with our experiments.

Our hope was that we could set the trees into the desired curve and then leave them to dry out so retaining the memory of this shape when later taken out the jig. By placing the memory of the curve into the wood it would greatly reduce much of the forces put on it so making it more manageable to work with structurally.

Having played with different ways to increase and control the curve of the timber we designed a structure that became both pavilion and bending jig. Robust columns and beams were used as a pivot over which to ben the tree trunks. Simple ply troughs were used as ballast to secure the thin end of the trunks to the ground, with the heavier thick end projecting beyond the footprint of the structure.

Images and Plans


School of Architecture and Design
Katrin Bohn


Project Context
Project Type
Care / Education | Community / Culture
Construction Methods/Techniques