Developers must take five feet off the height of a building planned for the corner of Valencia and Duboce streets and change the appearance of a rooftop parapet to accommodate concerns from Zeitgeist, a popular bar across the street, that the shadow cast by the building would impact business.

The San Francisco Planning Commission mandated the changes in a 6-1 vote Thursday. The five-foot slice is likely to come from lowering the ceiling of the ground floor commercial space.

The shorter building will still bring 28 units to the lot at 198 Valencia St., currently occupied by an Oil Changers auto service shop.

 Zeitgeist’s owners initiated the process to make changes to the design. They feared that shadows cast by the building would shade the bar’s patio during high-traffic times, driving away patrons and diminishing revenue.

In mid-January, commissioners directed the developer to conduct further shadow analyses and the bar owners to clarify how their revenues would be impacted and what suggestions they might have to mitigate the shadow impacts.

Lara Burmeister, the daughter of the bar’s founder, said they were unable to reach a deal with the developers prior to the hearing. A representative of the project sponsor declined to comment.

During the hearing, Burmeister suggested that an opaque parapet on the top of the planned building be replaced with transparent material and that the building height be reduced by five feet, saying those changes would eliminate a broad swath of shadow cast by the new building.

The Commission approved the project with those adjustments, as well as a few smaller changes to planter heights requested by the proposed building’s next-door neighbor, who had also filed a review request.

The overall height reduction, however, will likely come primarily from lowering the building’s ground floor commercial spaces. Since there are minimum height requirements for commercial space in that area, Planning department staff pointed out, that would require the developers to secure yet another approval for a variance from that height.

“We’re happy that the Planning Commission recognizes the value of preserving Zeitgeist,” Burmeister said after the hearing, calling the adjustments a “reasonable compromise.”

Supporters of the housing project without the height reduction – some of whom criticized Zeitgeist and the commission for prioritizing beer drinking over housing at the last hearing – were notably absent on Thursday. Instead, bartenders at Zeitgeist stated their case to the commissioners and brought supportive messages from other nearby businesses as well.

One man who said he lived in the units above Zeitgeist expressed concern that if the bar’s revenues dropped, the building owners might be unable to keep rents low. He estimated rents in the units above the bar average $744 a month. Burmeister acknowledged that part of the concern with keeping the bar viable was to ensure that the owners could hold on to the units above and keep them affordable. Another Zeitgeist bartender, who also lives above the bar, said he has to save money during the summers to survive the winters.

“Last month when it was all cold and very few would be hardy enough to go out in the backyard…I worked two days a week,” said Charles, another bartender. “When the sun shines, that’s when I make my money, that’s when our neighborhood gets a chance to come out and use our beer garden as their backyard.”

Other business owners chimed in as well.

“Zeitgeist [has always been] known as a very welcoming place to sit in the sun,” said Jackie Rednour-Bruckman of Good Vibrations, which has a location a few blocks away on Valencia Street.

The development “would completely block the sunlight to our establishment as well [and] negatively affect our business,” wrote the owners of Blackheart Tattoo, adjacent to Zeitgeist, in a letter. “A new structure of considerable height would cast a shadow in the afternoon hours where our business is located.”

Much of the discussion centered on how the building’s height could be reduced. The architect for the project argued that too much of a reduction in the height of each residential story would make the ceilings so low as to become unmarketable.

Reducing the commercial floor height, he conceded, would be possible, though it would significantly impact design and value.

Commissioner Christine Johnson, the lone dissenting voice in the final vote, early on voiced strong opposition to forcing the developer to lower the height of the building, especially by taking ceiling height off the commercial spaces and creating what she called “substandard retail spaces in brand new construction.” At one point, the discussion came down to the possibility of lowering the overall building height by 16 inches, at which Johnson grew impatient.

“I’m not willing to sit here and take any more of our time talking about 16 inches,” she said.

Commission President Rich Hillis had a different perspective on the commercial space.

“We all know there’s a diversity of retail heights and sizes. Sometimes smaller sizes make them quirkier and more interesting,“ Hillis said. “I would rather help Zeitgeist, as an existing business, than the theoretical new retail establishment.”