In Boston, apartments have roof decks; in Singapore, they have "void decks." Imagine a building raised on pillars, so that there's a large, empty space underneath. That space is the void deck - and most apartment buildings in Singapore have one.

What's the void deck good for? Everything, apparently. According to Singapore's Straits Times:

Like blank canvasses on which Singapore's ethnic rainbow is painted, void decks host everything from weddings and funerals to romantic trysts and day-long chequers sessions that draw retirees from all ethnic groups.

In Singapore it's perfectly normal to host a wedding for hundreds of guests in your building's void deck, or to drop off your kids at a childcare center set up each day in the open space under your building. Singaporeans make good use of the empty space. (The beautiful weather helps, of course.)

Yet the void deck is no accident of design. More than 80% of Singapore's population lives in public housing, in buildings designed to government specifications. And Singapore's government ensures that every apartment building mirrors the country's ethnic mix, with Chinese, Malays, and Indians living as neighbors in proportion to their share of the population - 77%, 14%, and 8% respectively. The void deck ensures that everyone gets to know each other, and each other's cultures. As the Times puts it, its pleasures are actually "part of Singapore's strictly enforced social policies aimed at ensuring harmony among the races in a region often torn by religious and ethnic strife."

That void deck might look empty, but there's a policy hidden there! It's another version of the power of the architectural empty space.