Habitat 67 (Axonometric View) Cité du Havre, Montreal — completed 1967 Moshe Safdie's experimental housing complex, conceived as his master's thesis at McGill and built five years later as the pavilion of the Canadian government for Expo 67. Three hundred and fifty-four prefabricated concrete modules — each weighing some ninety tonnes, cast in an on-site factory and post-tensioned together — interlock to form one hundred and fifty-eight dwellings, each with a private terrace formed by the roof of the unit below. The original thesis envisioned a complex ten times this size; what was built remains a fragment of an idea, conceived as a third way between suburban sprawl and the postwar tower block. Of all the structures built for Expo 67, Habitat is the only one that has retained its original function. The axonometric reveals what no facade can: the cellular logic of stacking and recession, the diagonal terraces, the negotiation between module and assembly. Designated historical monument by the City of Montreal in 2009. Moshe Safdie, architect.