The coincidence of the opening of a gargantuan international exposition at Montreal and of a new cathedral at Liverpool is provocative of questions about the relationship of architecture to society and of the sacred to the secular. In some ways an international exhibition like Expo ‘67 is to our century what the building of a cathedral was to an earlier one—lots of people and fun and a tempting opportunity for architectural gymnastics on a universal scale.

That, in terms of cost at least, is what such an exhibition is; and ever since Paxton’s Crystal Palace patrons and designers have seized their chance. But Expo ‘67 has another dimension. By the manmade islands, near the tense and justified hilarity of rival national displays, is the building of Habitat, permanent housing of an aggressively experimental kind. The units are piled up with a cubist exploitation of spaces between and through and over them. They are homes. They are extravagant; they cost per home about ten times what we would spend on local authority housing. Yet it all seems reasonable.

It seems reasonable because an exhibition is a chance to make innovations and experiments unhindered by a realistic budget. And that is one of the few ways in which experiments on a big scale can be made. (Otherwise the costs escalate, as in aircraft development.) In this case the designer can try out a social experiment: exploring ways of additively building up a group of homes individually expressed, the reverse of the tall slabs of storage for people with which we have become familiar.