One appeal was filed by the San Francisco Building and Construction Trades Council, a union, which argued that the development site, a former gas station, poses an environmental threat due to "highly contaminated soil and groundwater," the excavation of which could put at risk workers, neighbors and the environment in general. The Board of Supervisors landed unanimously on the side of city planning department staff, which countered that a comprehensive plan is already in place to mitigate potential site hazards.

Spiers, who conducted nine environmental studied en route to the mitigation plan now in place, has accused the union of using the appeal as a way of pressuring him into using 100% union labor on the project. The union has denied the accusation. Spiers, who was not available Wednesday for comment, has said he expects approximately 70% of workers to be union members.

In a 7-to-4 vote the Board also rejected an appeal of the project brought by neighbors, who argued that the development does not comply with "human scale" design parameters and would block their natural light. Board members voting to reject the appeal reportedly acknowledged adverse affects to neighbors but believed them to be outweighed by the opportunity to create more opportunities for home ownership without losing rental stock.

Spiers reportedly acquired the 22,000-square-foot lot for approximately $10 million a few years ago. The project calls for an 85-foot-tall, 150,000-square-foot mixed-use building that would house 115 residential units and 8,150 square feet of street-level retail. The development would include 17 units meeting the city's affordability requirement. Eighty-three parking spaces would be located beneath the building.