This is a small terraced house with a yard rather than a garden, and an old single-storey addition on the back that was narrow, tired and short of glass. The ground floor ran out of daylight before it reached the rear wall. 

The new extension is wider than the one it replaced and enlarges the kitchen and dining area, with French doors to the yard and a second glazed door to the side. Light now comes in from two directions and there is a clear route through the ground floor rather than a series of dead ends. 

The clients remade the yard themselves alongside the building work — stone paving, a brick path curving through gravel, a pergola over a bench against the party wall. The two moves work together. The extension is genuinely modest, but because the outside was rethought at the same time, the back of the house feels considerably larger than the floor area suggests.