Case Study #2: Crawford Partnership
Kentish Town, London by Crawford Partnership
Start on site date
Gross internal floor area
The rear extension to this three-storey Victorian terraced house consists of an extra room on the first floor, which provides a roof for a new kitchen and dining area.
A timber and birch plywood stressed-skin construction technique usually used for industrial buildings was employed to create the new spaces. This makes the extension much lighter than a metal-framed design - and 10 per cent cheaper to build.
The structure comprises of timber ribs, to which 15mm-thick birch plywood was glued, forming a rigid box. The plywood serves as a flange in the I-beam, increasing stiffness.
Once set, the newly formed box-panel has a structural efficiency roughly equal to that of an equivalent aluminium structure in terms of its strength-to-weight ratio. Spans of up to 6m can be achieved, even longer if the ribs are laminated.
Gennady Vasilchenko-Malishev, partner, Malishev Wilson Engineers