For eight years, professional sports teams and mega-project developers across California have relied on an obscure state law that fast-tracks environmental legal challenges groups use to slow or kill development.

The Golden State Warriors used the law — AB900 — to speed legal challenges to the Chase Center, the team’s new arena in Mission Bay. The A’s are hoping to use it for their planned waterfront ballpark at Howard Terminal in Oakland. The Los Angeles Clippers are taking advantage of the law on the proposed Inglewood Basketball and Entertainment Center.

Now an increasing number of big San Francisco housing developments are using the law to head off costly and time-consuming lawsuits.

One of those taking advantage of the law is the 774-unit development on the 11-acre UCSF Laurel Heights campus, which the Board of Supervisors unanimously approved Tuesday night. Other AB990 projects include the proposed redevelopment of the Balboa Reservoir with 1,100 homes, the reuse of the Potrero Power Plant with up to 2,600 units — as well as office and research space — and the 984-unit, two-tower proposal at 10 Van Ness.

That’s a total of up to 5,458 housing units in San Francisco that developers hope will avoid years of delays thanks to the state law. Statewide, 19 projects have qualified for the program, which is set to expire in 2021 if it is not renewed. Any project that has qualified before the law expires will be grandfathered in.

But to qualify, projects must be deemed “environmental leadership development projects.” That means they produce no net increase in greenhouse gases, are transit-oriented, achieve the highest Green Building Council rating and that cost at least $100 million. They also need the blessing of local lawmakers, as well as the governor.

Once a project qualifies, any lawsuit under the California Environmental Quality Act goes directly to an appeals court and must be resolved within 270 days. That compressed timeframe means AB900 can be a developer’s best friend, said land-use attorney Tim Tosta.

In San Francisco, a lawsuit over a mixed-use development at Fifth and Mission streets by developer Brookfield Properties and partner Hearst, owner of The Chronicle, dragged on for more than three years before it was thrown out earlier this year. A legal challenge to the redevelopment of Treasure Island, which includes 8,000 new homes, bounced around the courts for three years before it was dismissed. Lawsuits have also delayed Redwood City’s downtown plan, as well as San Francisco’s bike plan.

“Time is incredibly detrimental to projects,” said Tosta. “Just the fact of a pending lawsuit has the effect of stalling out projects. Opponents know how to play the time game to their advantage.”

Using AB900 requires a lot of up-front legal and political groundwork that can all be for naught if the project dies because of an economic downturn or other reasons. In the case of the Potrero Hill Power Plant, the payoff has been worth it, said spokesman P.J. Johnston.

“In exchange for greater scrutiny up front, the state moves you through a more predictable process,” he said. “Everyone’s feet are held to the fire.”

Environmental groups have criticized AB900, arguing it allows well-funded, politically connected developers to trample laws meant to protect the ocean, water supplies and clean air, for example.

But a recent analysis by land-use attorney Jennifer Hernandez found that only 13% of CEQA lawsuits are brought by environmental groups. Most are brought by labor groups against non-union projects or by neighborhood opponents objecting to issues like height, density, traffic or parking.

“It’s just one more cost piled onto luxury housing,” said Hernandez. “It’s another pay-to-play feature of CEQA. God forbid if you are trying to build housing for normal people.”

Even those critical of CEQA question why AB900 seems to benefit sports stadiums and massive developments in booming parts of San Francisco and Los Angeles and not regular housing projects in other parts of the state, which are also vulnerable to being bogged down by legal challenges.

“I’ve always found it mystifying as to why AB900 applies to major sports stadiums, but not housing projects,” said Assembly member David Chiu, D-San Francisco. “If it’s good enough for sports stadiums, at the very least, we should be having a conversation about why it isn’t applied more generally.”

State Sen. Scott Wiener said it’s no wonder housing developers in San Francisco are following the playbook previously mostly used by sports teams.

“The cost of building housing has gone through the roof and one piece of that is the process and delays and ligation around CEQA,” he said. “When a developer, whether for profit or nonprofit, sees another project tied up in court for years, that is terrifying.”

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jdineen@sfchronicle.com Twitter: @sfjkdineen