Hundreds of SoMa residents worried that their affordable rents could soon more than double can now rest easy. The city has cut a deal with the owner of South Beach Marina Apartments at 2 Townsend St. to keep the units at below-market prices.

The history of the apartments is unusual: The five apartment houses were built in the late 1980s and early 1990s with city redevelopment money, loaned in exchange for a promise that 20 percent of the units would stay affordable for 25 years. But as that time period neared its end, residents in the 101 units had been scrambling to find a way to ensure their rents didn’t soar.

In exchange for keeping in the rents down, the building’s owner will receive a $60 million credit from the city for future development projects — meaning the owner or its affiliates won’t have to build the equivalent of $60 million worth of below-market-rate units in future projects.

Dennis MacKee, spokesman for the Florida Board of Administration, a state pension fund that bought the Townsend Street apartments in 1999, said the fund is “pleased there is no displacement.”

“We have worked hard with the Board of Supervisors for several months to develop a fair and equitable solution,” he said.

Supervisor Jane Kim, who helped broker the deal, said it would benefit working-class San Franciscans.

“These aren’t simply below-market-rate units; these are the places that families have called their homes since 1985,” Kim said in a statement. “I am thrilled to announce today that we were able to successfully protect 101 homes and keep 101 families in place.”

— Emily Green

This looks familiar: Mayor Ed Lee’s plan to give developers extra height and density in exchange for building a greater number of affordable units all but died earlier this year amid fears the changes would drive out small businesses and destroy neighborhood character.

Now, the progressives who helped kill what was called an affordable housing bonus program have proposed their own version of the plan, which is basically the same idea scaled back to its bare bones.

The yet-to-be-introduced legislation would allow nonprofit developers who build 100 percent below-market units to add two additional stories beyond current zoning restrictions.

Supervisors Aaron Peskin and Eric Mar are authoring the legislation, which they plan to introduce in the coming weeks. That the legislation isn’t ready didn’t stop them from having a news conference on the steps of City Hall on Tuesday morning.

“It’s development without displacement,” Mar told supporters. “This is about density done right, with input from our communities. ... Progressives like me and others on the board and in our communities are not against development. I support development that is done equitably and without displacement.”

It’s unclear how many additional units the legislation would create, although the number is likely in the low hundreds.

Last year, nonprofit developers constructed about 10 buildings that were 100 percent below-market, creating between 700 and 800 units, said affordable housing advocate Peter Cohen, who heads the Council of Community Housing Organizations.

Cohen said a key benefit of Peskin and Mar’s legislation is that it has widespread community support, unlike the mayor’s affordable housing bonus program.

“You have to start where the political consensus is,” Cohen said, “rather than choking it down everybody’s throat.”

— Emily Green

Let there be life: The most-fought-over tree in San Francisco will see life yet.

The Board of Supervisors has voted to confer landmark status on the tall and slender pine — arborists can’t agree on its species — located in the backyard of a private house on Cook Street in the Inner Richmond.

The owner of the house wanted to cut down the tree, which stands around 100 feet tall and can be seen across the neighborhood. Many neighbors wanted it preserved.

The tiff got so contentious that neighbors secured a restraining order from the Public Utilities Commission prohibiting its removal. Lawyers were hired and a shaman was consulted — seriously.

Supervisor Mark Farrell, in whose district the tree is located, stayed clear of the dispute — until the Urban Forestry Council concluded that the tree should be landmarked because of its physical attributes, rarity, environmental benefits and cultural support.

Farrell followed the council’s suggestion and introduced landmark legislation for the tree. Last week, the Board of Supervisors gave the legislation, and the tree, its full stamp of approval.

— Emily Green