A gridshell may be viewed as a shell with large openings such that the remaining strips form a grid, retaining the strength and stiffness of the shell structure because of the doubly-curved configuration. Few have been built due to lack of knowledge and data. The Downland gridshell, a museum workshop near to Chichester, Sussex, is a double-layer timber gridshell consisting of four layers of green oak timber laths forming two three-dimensional mats linked together. Long lengths of laths were formed by finger jointing using a polyurethane liquid adhesive specially developed to suit green oak. Fireproofing was not required. A patented node connection system was developed which enabled the roof to be formed from an initially flat mat by gradually lowering the scaffolding prop system. Models were used to predict the behaviour of the structure. It is proposed that the knowledge gained of gridshell behaviour, construction and cost will make the design and construction of future timber gridshells a more viable option. 4 refs.