Using a palette of brick and timber the rear extension of this semi-detached house creates a new open plan kitchen-dining space that spills out into the garden. Brick retaining walls extend into the garden, using an awkward change in ground level to define a terrace and structure the landscaping beyond. Inside the walls support a timber roof which frames views to the surroundings trees through clerestory windows which bring dappled sunlight into the plan. A walled garden room for growing plants and people.