Nearly two years after a smattering of tiny homes popped up in the Bay Area as a peculiar new way of housing homeless people, the technique is exploding from one end of the region to the other. Nearly 1,000 tiny homes or their close cousins - stackable modular housing units, typically with less than 200 square feet of living space - are being planned in San Francisco, San Jose, Richmond, Berkeley, Oakland and Santa Rosa. Tiny units can be built in a fraction of the time it takes to construct typical affordable housing, at a sliver of the cost, and that means a lot of homeless people can be housed quickly. In one of the most expensive housing markets in the nation, with tent-camp problems everywhere, that prospect sounds like a game-changer to officials. Contra Costa has a $750,000 federal homelessness grant to pay for 50 stackable micro-units of supportive housing, and Richmond Mayor Tom Butt would like to see them in his city. Developer Patrick Kennedy brought a prototype of his MicroPad unit to Richmond in November, and county and city leaders say they are leaning toward choosing it. Tiny homes have also caught on in San Jose, where the City Council this month approved plans for a village of 40 of them for homeless people. You really have two options," said [city Councilman Raul] Peralez, who said he wants the village in his downtown district. "You can allow the homeless to live on the streets, or you can provide ... shelter [and] services. In my mind, that's a way better option for managing this community in an organized way."