Archello Awards 2026 · Enter your projects before 30 September 2026
Archello Awards 2026 · Enter your projects before 30 September 2026
Twin Pitches
Jim Stephenson

An Edwardian house low-carbon retrofit and extension in London

Applied products
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Twin Pitches shows what good architecture can do for an ordinary home. Atelier Baulier transformed a tired Edwardian semi-detached house into a thoughtful, future-proofed and deeply liveable home, making the most of existing volumes whilst minimising environmental impact.

photo_credit Jim Stephenson
Jim Stephenson
photo_credit Jim Stephenson
Jim Stephenson
photo_credit Jim Stephenson
Jim Stephenson

The existing fabric was upgraded throughout with bio-based materials, an unsound lean-to removed, and two new volumes woven in to unlock the plan. The distinctive sawtooth roof of the rear extension takes its cues from the existing rooflines, sending light deep into the plan.

photo_credit Jim Stephenson
Jim Stephenson
photo_credit Jim Stephenson
Jim Stephenson
photo_credit Jim Stephenson
Jim Stephenson

Challenging conventions, natural and low-carbon construction methods were used throughout, including screw piles for the extension foundations. Wood-fibre insulation, airtightness upgrades and an air-source heat pump bring energy use to 51 kWh/m²/yr.

Throughout, a consistent palette of natural materials — lime plaster, plywood, coloured linseed oil — brings quiet generosity to every room. Frugal yet elegant: Twin Pitches sets a powerful exemplar for sustainable domestic retrofit.

photo_credit Jim Stephenson
Jim Stephenson
photo_credit Jim Stephenson
Jim Stephenson
photo_credit Jim Stephenson
Jim Stephenson
Caption
Caption
Caption

Project credits

Architects

Sustainability

Low Carbon
Operational Emissions / Energy

Product spec sheet

Lime plaster and Lime render
Bathroom tiles
Windows + extension fenestration
Linseed paint
Kitchen backsplash + island worktop
Linseed oil stains

Project data

Project Year
2024
Primary Building Material
Brick
Building Area
168 m2
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