Beating New York to the punch, San Francisco’s Board of Supervisors voted in December to alter the city’s building code to allow for a pilot program of so-called “micro apartments,” meaning dwelling units as small as 150 square feet in living space, for a total of 220 square feet (including the kitchen and bathroom).

The move will allow for the construction of more than 375 of the tiny apartments in the City by the Bay, with an assessment of their impact to follow completion. Until now, San Francisco’s building code allowed for apartments offering a minimum 220 square feet of living space. The ordinance, which proponents say will expand the tight housing market and help reduce the environmental impact of future development, still needs to be signed by Mayor Ed Lee.

“San Francisco has one problem above all other problems, which is that housing costs too much,” said Gabriel Metcalf, executive director of San Francisco Planning + Urban Research Association (SPUR). “Allowing people to live in smaller units is one of the very few tools we have for potentially helping a lot of people.”

New York Mayor Michael Bloomberg has been trying to secure his own ordinance to allow micro apartments—which in New York would mean studios and one-bedroom apartments of no more than 300 square feet. But Bloomberg thus far has not secured approval, despite the success of a competition, called adAPT NYC, which attracted ideas worldwide. San Jose, California, has already approved such apartments, and they’re being experimented with in Seattle, Chicago, and Boston.

The San Francisco micro apartments are expected to cater mostly to singles and to be built in dense neighborhoods like the South of Market (SoMa) district. Published rent estimates of some local micro apartments have ranged from $1,200 to $1,500 a month, much less than the city’s average of over $2,000 a month. One example is Smartspace SoMa, a 23-unit, micro apartment building by developer Panoramic Interests in the South of Market district. The firm is working on other developments in San Francisco’s Mission district and in Berkeley.

The developer’s website notes a quote by critic Lewis Mumford: “Cities exist not for the passage of cars, but for the care and culture of human beings.”

Not all are enamored of the idea, however, worrying that micro apartments may be too cramped or that smaller apartments may even drive up the price of larger units. “You are still talking about very small units being very expensive. If these places that are 200 square feet are going for $1,500, what is that going to do to the rest of housing prices in San Francisco?,” city supervisor David Campos told the AP.

Metcalf of SPUR had a different kind of criticism: that the city isn’t allowing enough of the apartments, instead choosing to go with the pilot program before finally moving ahead.

“When you consider how many thousands of units short we are on housing, to micro-manage it with just a few hundred units is definitely a very timid response to a serious problem,” he said.