"This legislation has had quite a winding road to get where we are today," Supervisor Scott Wiener said.
Asking his fellow supervisors for their vote, Wiener spelled out the compromises he's rolled into the bill to allow tiny apartments with only 150 square feet of living space, 220 counting the kitchen, bathroom and closet.
"Some of us call them shoebox apartments as well, that term has been adopted," Housing Rights Committee spokesperson Sara Shortt said.
Shortt was initially against the tiny apartments, fearing they would replace units big enough for families.
"We don't want it to become like Singapore where so many families have been displaced by these micro-units that they're now having to go back and change the laws to keep it at 375 square feet minimum," Shortt said.
But wiener agreed the micro-units will be for new construction only so landlords can't chop up an existing building. He expects these to rent for $1,500-$2,000 per month.
"And for some people having that lower cost option is the difference between being able to stay in the city or not," Wiener said.
Supervisor Jane Kim worries new buildings full of these little units could cause the population in her crowded district, which includes the South of Market neighborhood, to swell by another 30 percent.
"I really do hope that if these units do go forward that they are tried out in other neighborhoods," Kim said.
Wiener agreed to cap the initial round of building permits at 375 micro-apartments.
Supervisor John Avalos still wasn't sold.
"I think overall, this does not make a lot of sense for the San Francisco that I know," he said.
In the end, he was the only "no" vote.
But after a 10-1 victory, Wiener has one person left to win over: the mayor. So far he has not said where he stands.
"I always have a concern whenever people are changing the standards, but I do think there might be good policy reasons, I'll just take a look at it," Mayor Ed Lee said.
If the mayor signs the tiny apartments into law, the total number allowed will stay capped until there's a study and another vote by the Board of Supervisors on whether to allow more.