Backyard ADU Permits Filed at 466 Frederick Street in Cole Valley

Plans have been filed for a two-story backyard apartment building at 466 Frederick Street in the Cole Valley area of San Francisco. The application would add two accessory dwelling units behind an existing three-story multifamily house. Heuer Trust is listed as the property owner.

Design work was handled by Openscope Studio. The expansion would add about 1,300 square feet, with one one-bedroom unit on each floor. Both units would open onto the shared backyard. The renderings show a simple boxy volume with a sloped roof and horizontal lap siding.

The parcel sits on Frederick Street between Stanyan and Cole streets, about three blocks from Haight Street and the recently completed affordable project at 730 Stanyan Street. Construction is estimated at roughly $320,000. Public records show the property last sold in 2004 for $865,000. A 2006 filing proposed a three-story rear addition and conversion to a six-unit building.

For developers and lenders, this is a small infill ADU project in a built-out neighborhood, and it illustrates how backyard units can add density on existing lots.