The Wooden Annex is a single-storey, fully timber extension to a 1950s end-of-terrace house in South London. The addition of the annex accompanied a complete refurbishment of the existing house, creating increased and improved open living space for the homeowners.
LocationLondon
ArchitectTsuruta Architects
Project TypeSmall project
Building TypeHome extension
Structural EngineerKarsten Weise
Main ContractorJK London Construction
Wood SupplierJames Latham
Product InfoAccoya, New Zealand; birch plywood, Russia
Timber SpeciesBirch
Timber ElementsAccoya cladding and ringbeam; plywood cassettes
Upfront carbon emissions (A1-A5)3219 kgCO₂ (including substructure, superstructure and envelope)
Structural materials usedtimber 5.2t; aluminium screw pile 0.8t




The Wooden Annex is a single-storey, fully timber extension to a 1950s end-of-terrace house in South London. The addition of the annex accompanied a complete refurbishment of the existing house, creating increased and improved open living space for the homeowners.
Designed by Tsuruta Architects, the annex has added a light and minimalist dining area that projects out into the garden, making efficient use of the long and narrow space. The large garden has nine different adjacent landowners and three beloved mature trees, all of which influenced the proposed design. The tree root protection zones on the site determined the use of screw piles and the consequent idea of an entirely timber building, including its foundations.
The annex was built using a flat pack of over a thousand digitally-fabricated pieces, all assembled onsite. This customised construction process was developed by the Tsuruta design team to optimise the use of timber and minimise site waste, producing an impressive, environmentally low-impact building.
Relying on a close and integrated relationship between the architect, client and main contractor, JK London Construction, the Wooden Annex demonstrates the potential of incorporating digital fabrication within domestic-scale timber projects.