Wooden Roof

Small Project

Wooden Roof

Project Info

“A simple extension that creates a light and airy garden room.” —Jim Greaves

Tsuruta Architects was faced with a construction challenge when developing the design of this airy London conservatory. A traditional conservatory features a pitched roof, enabling efficient water-shedding, but because their project was attached to a Grade 2-listed home, the architects had to give the roof a much shallower profile to avoid it overshooting the height of an adjacent boundary wall.

The result is an exceedingly elegant solution to a tricky set of restraints. To ensure that the roof’s shallow elevation could still drain efficiently, Tsuruta Architects created a series of higher pitches that direct rain water toward a longer and gently-sloping primary gutter. These pitches are composed of a wooden diagrid frame whose beams are fixed without glue or mechanical fixings. “This process follows traditional Japanese construction techniques where complex geometric joints effectively lock the wood together,” noted jury head Jim Greaves. Like the rest of the conservatory, the roof is made from tacetylated wood components, with the only other material addition being a covering of Four Seasons glass.

The user’s experience of the conservatory is entirely mediated by its roof. The diagrid structure creates a light-filled space whose shadows and highlights evoke a woodland clearing. Externally, the wooden faces have been charred to protect against the damp, and internally, they are oiled such that they can breathe – both natural treatments which ensure the longevity of the material.

Watch judging tour on YouTube.


ArchitectTsuruta Architects

Structural EngineerWebb Yates

Wood SupplierArnold Laver

ContractorJK London Construction

SpeciesAccoya (New Zealand), ash (Canada)

JoineryPracownia Wystroju Wnetrz Art Deco -R

wooden roof
Wooden roof