Cork Loft | Office S&M Architects

We chose cork because it could meet environmental, technical, and aesthetic ambitions in one material. It is regenerative, lightweight, insulating and naturally resistant to moisture and mould, making it particularly suitable for a loft extension on an existing Victorian house. It also offered a distinctive visual character that could evolve over time through weathering. We explored more conventional loft materials, including standard cladding, insulation, and render systems, but these lacked cork’s combination of low embodied carbon, versatility, and expressive potential. The final choice came from testing how one material could perform across multiple applications.
Catrina Stewart, Director and Co-Founder at Office S&M Architects

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Cork Loft is a loft extension in Walthamstow designed by Office S&M Architects as part of a wider refurbishment and retrofit of a long-neglected Victorian house. The clients sought a highly sustainable design that challenged conventional loft extensions while improving the poor internal conditions of the existing home, which had suffered from damp and mould.

The design places cork at the centre of the project. Chosen for its regenerative harvesting process and strong thermal and acoustic performance, cork is used extensively as cladding, insulation, flooring, and even within the render. Its lightweight properties made it particularly suitable for a loft structure supported by existing foundations, while its resistance to moisture and mould directly addresses the issues present in the original building.

Rather than concealing the extension within the roofscape, the proposal embraces contrast. It respects the proportions of the Victorian context while establishing a distinct identity that evolves over time as the cork weathers. The façade has been carefully developed to reveal a subtle pattern as it fades, adding depth and character.

Internally, the project balances sustainability with spatial quality and atmosphere, introducing light, colour, and carefully framed views to create a distinctive and uplifting living environment.

Credits
Architecture Firm: Office S&M
Lead Architects: Catrina Stewart

Photography: FRENCH + TYE - www.frenchandtye.com

Other participants

Structural engineer: Foster Structures

Quantity surveyor: SJB

Approved building inspector: wilkinson Construction consultants

Main contractor: square mile builders