SF is building more housing now than in recent history, but you probably still can't buy a home

A 136-unit rental modular housing project takes place in the Bayview in San Francisco, Calif., on Monday, September 28, 2015. San Francisco, home to arguably the most expensive housing market in the country, nearly doubled its historic average number of homebuilding permits in 2017, a new study found. less A 136-unit rental modular housing project takes place in the Bayview in San Francisco, Calif., on Monday, September 28, 2015. San Francisco, home to arguably the most expensive housing market in the country, ... more Photo: Liz Hafalia, The Chronicle Photo: Liz Hafalia, The Chronicle Image 1 of / 27 Caption Close SF is building more housing now than in recent history, but you probably still can't buy a home 1 / 27 Back to Gallery

San Francisco, home to arguably the most expensive housing market in the country, nearly doubled its historic average number of homebuilding permits in 2017, according to a new study from the real estate site Trulia.

In the past year the city approved 95 percent more home permits than it did, on average, between 1980 and 2016, according to figures compiled by Trulia.

San Francisco "won the great homebuilding race of 2017," Trulia employes write on a blog post about the findings. But the reality is much more complicated than that.

The city issued 6,270 permits in total last year, according to U.S. Census data, 92 percent of which went toward high-density building projects (five units or more). Only seven percent of these permits went to single-family homes. Building up – rather than out – is a trend across metros, Trulia found. The increase signals a shift that may be hard to detect for San Franciscan's struggling to afford a place to call home.

"It's a shift that signals that the city is becoming more aggressive in its efforts to combat its affordability crisis," the study authors write. "What's more, a large share of its new units are multifamily units, which should help rents continue to cool this year."

While the numbers sound promising with history taken into account, they become downright perplexing when compared to the building rates in other cities.

For example, Austin issued 80 percent more permits on average in 2017 than over the previous 36 years. That translates to nearly 26,000 permits in total – more than quadruple the number of permits issued in San Francisco over the same year. Of the 26,000 permits in Austin, almost 60 percent were issued for single-family homes.

San Francisco is increasing its housing stock, indeed, but it's all relative. The high percentage of permits issued to five-plus unit buildings will likely "put downward pressure on rents," the study says, "rather than home prices."

In other words, it might get easier to find a reasonable apartment in the near future, but an affordable home? Probably not.

Michelle Robertson is an SFGATE staff writer. Email her at mrobertson@sfchronicle.com or find her on Twitter at @mrobertsonsf.