The project, which would feature retail on the ground floor and residential and office space on the upper three floors, began in 2011. The Wongs have made eight revisions to the 31,157-square-foot project, she said.

The board added a further caveat: The next time the troubled project comes before the Architectural Review Board will be its last. The plan will either get a "thumbs up" or a "thumbs down" recommendation, and the project will then go to the City Council for a final approval -- or rejection.

The four-story commercial and residential project from developers Jaime and Elizabeth Wong has already gone through four architects since its first city hearing in 2013. But members of the board declared the modernist project "unresponsive" to the City Council's direction last year to reduce its mass and make it more compatible with its surroundings, which include historic buildings on University and the adjacent Kipling Street, a narrow lane with multiple Victorian-style buildings.

To the east, it would front the narrower Kipling, which is dominated by the Victorian homes and a city parking lot. Directly across Kipling from 429 University, however, is the blocky, semi-industrial wall of the former Apple Store.

On the south side, it would front bustling University Avenue, where an eclectic mix of architectural styles is dominated by Spanish-style buildings, some designed by Palo Alto's renowned architect Birge Clark. The historic Varsity Theatre lies catty-corner to the parcel.

Throughout the process, their project has come to embody local political debate about over-development, preservation of neighborhood character versus architectural evolution and when to follow the spirit versus the letter of the city's zoning laws.

A prior version of the Wongs' project secured the board's endorsement in February 2015 only to be halted by a neighbor's appeal and the council's direction on a 5-4 vote in May 2015 that the project be revised.

"This is insane for it to go on from 2011 to 2016. A traditional building will not work because a retailer doesn't want a traditional building. You're throwing us out on the freeway. You don't realize that every little word you say costs us more money," she said.

"To put four stories here on this narrow street ... just is not right," Harbour told the architecture board in March. "If we were here dealing with maybe a two-story structure with a third-floor set back, we probably would not (be) here."

Besides the question of architectural compatibility is the issue of the four-story project's sheer mass. Harbour has long maintained that a four-story-tall structure doesn't belong on Kipling, especially not when replacing two one-story buildings.

Throughout the project's many iterations, the proposed building has retained a modern aesthetic. Some versions have nodded toward neighboring buildings by using similar materials, such as natural stone. But none has attempted to mimic or emulate the designs of adjacent structures.

CORRECTION: This story previously stated that the vote was 3-0. Board member Kyu Kim cast a dissenting vote because the project had a new design and a new architect, and an additional hearing with more significant changes in massing and revisions to address the concerns of the city council would be more appropriate.

"In my opinion, whatever comments I'm going to give you are going to be in a public venue. The perception works both ways, and it sounds fishy meeting with developers" outside of the public arena, he said. Whatever recommendations he would make in private would be the same as the ones he makes at board meetings, he said.

In a firm exchange, Wong complained that current board members are not accessible as past members had been under then-Chairman Randy Popp. They have refused to meet with her to discuss the project and how it might be changed, which would be helpful, she said.

"As a new design (and new architect) was presented to the board, I felt that an additional hearing with more significant changes in massing and revisions to address the concerns of the city council would be appropriate," he said in an email.

Kim questioned whether the project had changed so much that it should have a new application because it is a new design. Kim voted against the motion.

Chairman Robert Gooyer added that some of the square footage in the 18-by-18-foot and 20-by-17-foot bedrooms in the third-floor residential units could be reduced to help with setbacks to shrink the mass. He rejected the argument that the walls of glass would adequately reduce the feeling of massiveness and said it was not compatible in the architectural context of that area of University.

"As it is, it still reads as one large building. It still has the sense as one big structure," he said. "The building to me still feels a little mysterious. It needs to feel a little welcoming."

Despite Bellomo's attempts to divide the building's width on University into five "bays," board member Kyu Kim suggested the architect add more elements to break up the building facade with varying setbacks and slightly different color schemes.

Board member Alexander Lew, in an effort to break the design logjam, presented a few examples of architectural styles in San Francisco that he said represent the kind of vision he has for the Wongs' site. The buildings are modern in their use of concrete materials and glass, but they include elements such as a sense of verticality that visually breaks the building up into three or four segments.

But the board remained troubled by the mass and overall design. They acknowledged that University Avenue has a variety of architectural styles, but said the area around Kipling is different because the street is narrow and the buildings on University and Kipling are of historic styles.

The Wong's newest architect, Joseph Bellomo, noted that changes to the facade were more in keeping with the mix of building styles currently up and down University Avenue, including two at 102 and 116 University that he designed. The building now sports walls of glass that he said would let in more light and reduce the sense of large mass, and setbacks on upper floors would make it so people in smaller neighboring buildings on Kipling wouldn't be able to see the building's full height, he said.

The council voted 9-0 last November to send the project back, again, to the Architectural Review Board. But the board agreed on Thursday that the project, while better than it had been, only changed its facade. It did not change the square footage or the design in a way that would take it from a blocky, horizontally oriented structure to one that is harmonious with the surrounding district.

Frustrating the Wongs, however, is the fact that the project meets objective development standards, such as parking requirements and allowed square footage. The issue of compatibility is largely subjective, they alleged -- a perspective that city officials agree with, even while insisting that the project be redesigned.

On Thursday, he reiterated these sentiments, adding that if the project was on the corner of a wider street such as Waverley there would not be opposition.

Controversial plan sent back to drawing board, again

429 University Ave. development in Palo Alto to get only one more architectural review