S.F. proposals seek office restrictions, demolition scrutiny

Two San Francisco supervisors introduced separate pieces of legislation Tuesday aimed at preserving housing in the city. Supervisor Hillary Ronen, D-District 9, proposed an ordinance that would ban new office space on the upper floors of some developments zoned as “urban mixed use” in eastern neighborhoods — generally portions of the Mission District, Potrero Hill and the Dogpatch. The UMU zoning designation, created more than a decade ago as redevelopment of the neighborhoods was just beginning,…