Photo: Paul Chinn / The Chronicle Photo: Paul Chinn / The Chronicle Photo: Paul Chinn / The Chronicle

Developer Paul Iantorno is pretty sure he’s done everything he could to win community support for the 63-unit apartment complex he wants to build at the corner of Folsom and Russ streets in San Francisco’s South of Market.

He’s agreed to make 15 of the new units below market rate. He’s promised to temporarily relocate the four tenants living on the site to a building he owns in the Mission and then give them permanently rent-controlled units in the new property when it opens. Taken together, the rent-controlled units and the 15 affordables make 30% of the project below market rate, twice the required amount.

He’s assured the building’s commercial tenants, which include Fondue Cowboy, Deli Board and the San Francisco Leather Alliance, that they will have space in the new building, should they want it.

And he committed to paying $150,000 for an attendant to oversee the bathrooms for three years across the street at Victoria Manalo Draves Park, restrooms that have become a magnet for addicts looking for a place to shoot heroin or smoke meth.

But there’s one thing he can’t control: the shadow that the 65-foot building would cast in the early evening on the park. And in a part of SoMa that ranks among the least open space in the city, the shadow cast on a precious bit of green space might be enough to kill the project.

On Tuesday, the Board of Supervisors will hear an appeal of the project, which would replace several smaller buildings at 1052-1060 Folsom St. and 190-194 Russ St. The project won approval from both the Recreation and Park Commission and the Planning Commission late last year.

At issue is the shade the new building would cast on Victoria Manalo Draves Park, a 2-acre open space next to Bessie Carmichael School.

The proposed building would cast new shadow on the northeastern portion of the park, which is home to the basketball court, children’s play area, seven fixed benches and a grass section frequently used by dog walkers. The southern half of the park, where the baseball field and batting cages are, would not fall under the shadow.

On the longest day of the year, June 21, the project would shade the northeastern quarter of the park, starting between 5:46 and 6 p.m. and lasting about 100 minutes. It would cover 20,064 square feet, equal to 18.24 percent of the total park area. Existing shading at that time covers 30 percent of the park area.

While the building project is small compared with many of the residential developments in the city’s pipeline, it is being held up as an example of the NIMBY politics that make production of housing in the city slow and difficult.

Mayor London Breed said the fight shows “why housing is so expensive in San Francisco.”

“It’s unacceptable that anyone is actually talking about this project being shut down because of a shadow that both the Rec and Park Commission and Planning Commission found to be insignificant,” Breed said. “We can’t keep delaying and obstructing new housing if we ever want to meet our housing goals so people can afford to live in this city.”

San Francisco’s sunlight ordinance was passed in 1984 as a response to proposals that cast shadows on Portsmouth Square in Chinatown. Proposition K blocks construction of any building over 40 feet that casts an adverse shadow on Recreation and Park Department property unless the Planning Commission decides the shadow is insignificant.

Photo: Photos By Paul Chinn / The Chronicle

David Woo, community development coordinator for the South of Market Community Action Network, the group that appealed the development, said the park should be afforded the same “zero-shadow tolerance” the city has as a policy for North Beach and Chinatown.

SoMa residents spent spent decades pushing to get the land dedicated for VMD Park, which opened in 2000. Since then the park has only become more precious as SoMa’s population has grown — over the past decade about 60 percent of new residential development in San Francisco has been in District Six.

“It’s been a community-led fight every step of the way,” Woo said. “Our community demands have always stayed the same — we are asking for zero new shadow on VMD. It’s an equity issue.”

The project may be tainted because the property is owned by Sergio Iantorno, Paul’s father, who has been criticized for using the state Ellis Act to evict rent-controlled tenants on other properties.

David Ho, a lobbyist who worked on the project, said it seems like the younger Iantorno is being punished for his family’s earlier business practices.

“This is very generous community benefit package for a small project,” Ho said. “This is an example of what we want developers in San Francisco to be like. I don’t think another developer would go down this pathway again, given how (Iantorno) has been treated.”

Rudy Asercion, the former executive director of the West Bay Filipino Multi-Service Center, was a friend of Draves, the park’s namesake and a gold-medal-winning Olympic diver in the 1940s, and says she would have approved of the development.

He said that the park is not used by children and families as much as it should be, in part because the open space is often taken over by drug users and homeless people. Having 100 or 200 new residents living right across the street from the park — as well as the $150,000 for bathroom security — will make it safer and busier, he said.

“The people who live in those places will go to the park, keep an eye on that park, and displace the drug users who are making families and children afraid to go to the park,” Asercion said.

Opponents are “not interested in trading money for shadows,” Woo said. “I don’t think $150,000 is going to solve the drug problem in VMD Park.”

On Friday, Supervisor Matt Haney, who has not taken a position on the issue, convened a meeting between the developer and opponents. Attendees said that there was little movement on either side.

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