Wimbledon extension develops modern equivalent to traditional brick homes

Can you briefly describe the project?

A family of four, including two young children, approached us to develop designs for extending, remodelling and refurbishing their south London home. We replaced the previously unkept garage and half turret with a series of front, side and rear extensions, alongside a new sheltered front porch and a bay window. At the rear, a full-width dormer has drastically expanded the internal living spaces, while we have added an inset dormer/balcony to the front roof slope. The fully remodelled Kings Road House has been designed to exacting requirements, providing generous living spaces, full of warmth and life.

Who is the project for and what was the brief?  

The client had recently purchased a dilapidated Edwardian detached home in a part of London where they wanted to live, and saw an opportunity to create a truly bespoke family home. They provided us with a schedule of spaces and expressed an interest in modifying the building's external appearance while improving its thermal efficiency.

 Were there any significant factors that influenced the design?

After studying the local Victorian buildings, we developed a modern equivalent to the traditional brick homes along Kings Road, re-establishing the design principles of the South Park Gardens Conservation Area by reinstating brickwork to all facades in place of white render. 

As well as the client brief, we also considered neighbouring site conditions. A large, unsightly and overbearing two-storey extension to a property on the western boundary drove our decision to position the ground-floor extension on this side of the plot. To address this, we angled the rear extension away from the neighbouring extension to face the newly landscaped garden. This strategy continued throughout the building, with an angled bay window placed in the main bathroom to direct views towards the gardens. This design language of chamfers and angles was applied throughout, shaping the front garden walls, entrance porch, window reveals, internal lightwell, columns and bay windows. The subtle angles create inviting and softened spaces and direct views effectively.

How did you treat the exterior?  

Parts of the front and rear walls have been retained, along with the first-floor floor structure and several internal partitions. The entire house has been insulated on the outside of the existing solid brickwork walls with a Eurobrick insulated brick slip system, which offers significantly better thermal efficiency than insulating on the inside with insulated plasterboard. A textured limewash process known in Scandinavia as ‘Sækkeskuring’ was used over the face of bricks across the front, rear and side facades to add to the now monolithic appearance.

We designed a new masonry canopy to unify the front elevation and emulate traditional brick banding seen across surrounding Victorian houses. 

How did you design the interiors?

We designed the interiors with a simple material palette that focused on craftsmanship, quality and texture. It included bespoke joinery throughout, designed by us.

A first-floor rear bay window is angled away from surrounding homes, enhancing views and privacy, while beneath this, within the punctured extension, a planted lightwell sits between the study and garden-facing seating area to separate work, dining and lounge – supporting cross ventilation.

There’s a playful kite-shaped roof light and a sculptural, turned oak handrail. Exposed elements contrast with the new building fabric, such as the retained front chimney breast, which provides a memory of the original house, drawing the eye up through the building.

What was your approach to sustainability? 

With a north-south aspect, careful glazing of the south elevation maximised solar gain during winter, flooding interiors with light and harnessing solar heat to reduce reliance on artificial heating systems. Opening up the house from front to back facilitates cross-ventilation for passive cooling, while an internal lightwell with high-level glazing helps purge excess heat during the summer.

The insulated brick slip system augments the building’s thermal mass, regulating indoor temperatures and fostering a comfortable living environment year-round. Internal solar shading techniques, including concealed blinds and solar control glass, mitigate solar heat gain and glare, creating optimal comfort for occupants while maximising energy efficiency.

Describe the main challenge and how you overcame it

Despite numerous site and structural surveys and ground investigations, we encountered issues with elements of the existing structure. We hadn’t expected the ground-floor structure to vary so much from one room to the next. The former kitchen had a thick concrete slab whereas the main living spaces had raised timber floors. To achieve a level finish that was structurally stable, well-insulated and ventilated, we agreed with our client to rebuild the ground floor as a block-and-beam floor, which incurred additional costs. But we always advise that a contingency sum be allocated for any retrofit project to address such unforeseen issues.

In the aftermath of Covid, materials were difficult to obtain, alongside increased lead times and costs, meaning all had to be considerate and collaborative to realise an outcome everyone was happy with.

What is your favourite detail in the project?  

Our favourite detail is the front entrance sequence, which establishes the building’s language right from the street. Inspired by the nearby Victorian terraces, we reimagined the front walls, path, bay window and inset porch in a modern style. A thoughtful combination of materials – brick, concrete and timber – adds tactility to the front elevation, drawing you in even before you enter the front gate. The interplay of light and shadow on the front elevation creates dynamic patterns, and the materials are carefully arranged with subtle angles, enhancing the overall relief of the project. 

Are there lessons from this project that might be applied elsewhere?

Always try to maintain trust between all parties involved in the building project. Ensure that communication between client, consultants and contractors is maintained to the best possible level – and try to be prepared for any unforeseen challenges and know how best to resolve them! 

Tom Munday is an associate at Matthew Giles Architects

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Key data: 
Total cost Confidential 
Area of extensions Ground floor: 52m², loft: 20m²
Total GIA 299m²
GIFA cost £3,712m²
Predicted annual CO₂ emissions 10-15kgCO₂/m² 
Predicted improvement in annual CO₂ emissions 40-50%
Predicted embodied carbon 300kgCO₂/m²
Predicated annual operational energy 100 kWh/m² 
Original EPC rating F
Post-retrofit EPC rating B/C