Tennyson Road

Walthamstow,  2021
158 m² / 1,700 ft²

An innovative, CNC-milled, stepped extension brings a crafted, unique quality to this whole house refurbishment in Walthamstow. Though its unusual roof form and hand-built frame arose due to tight planning and budgetary constraints, this ingenious vaulted space has become the family home’s best feature.

The curves of the roof accommodate strict planning constraints around eaves and roof heights while maximizing internal ceiling height. In designing, CNC milling then constructing the birch ply frame, in collaboration with our contractors, we reduced costs as well as environmental impact, thanks to this no-waste process.



Combining precise measurements with standardised components generates a sense of uniformity across the two different volumes. Essentially, a ‘kit-of-parts’, the structure also allows great flexibility for adaptations, including two deep skylights inserted into each roof, bringing light deep into the rear extension.

The same CNC methodology was used to create an attractive sliding door that seals off the smells and sounds of this kitchen extension from the rest of the house.


‘We love the vaulted ceiling, the warmth of the wood and all that space and natural light! In the summer, the window is open, the seat becomes the pride of place, and the kids can clamber in and out of the garden.’  –  Stephanie



To keep the scheme within budget, we undertook construction of the plywood ribs themselves. This plan illustrates the process for calculating the quantity and cut-outs required for the birch plywood ribs.

These were measured, templated and tested on site, with specific amends made to suit particular circumstances. CNC templates were then set-up to minimise sheets (further reducing waste and cost), all of which were cut and delivered to site. Joists were then glued and fixed on-site by the contractor.

Through the bedrooms, bathrooms and circulation spaces we used strong colours to generate warmth, focus, and low cost, high impact character for what is now a robust, flexible and generous family home.

Our client wanted to expand their cramped Victorian terraced house to accommodate a growing family as well as visiting relatives. To squeeze in 3 bedrooms and 2 bathrooms we designed a loft conversion and reconfigured the first and ground floor and created these two unusual extensions – through two different planning applications – to form a space that feels like one generous gathering kitchen/dining and lounge area.