Deep in an ordinary garden city in Halle, the Brussels-based office AHA offers a curious and amusing version of the endless home extension.

It begins like any other Belgian story. The happy owners of a small semi-detached house in Halle, two young women, decide to contact the architect Aurélie Hachez after seeing her on a local architecture TV show, ‘Une brique dans le ventre’. The commission was simple: they needed an architect to enlarge their house as the family was about to welcome a little girl. A blueprint in their possession outlined the maximum volume authorized by the urban-planning department, thus clearly defining the range of possibilities.