639-641 3rd Ave, San Francisco, CA 94118

The two-unit residential building at 639 3rd Avenue in the Inner Richmond, owned by the Tsang Family Revocable Living Trust, is a two-story flats and duplex structure built in 1905. The property's recent history, particularly in 2024, has been marked by significant sewer-related issues, with five documented sewage backup incidents from the side sewer vent between July and November 2024, followed by sewer replacement work completed in July 2024.

These recurrent sewer problems suggest an ongoing infrastructure challenge that should be noted by current and prospective residents. The building underwent window improvements in 2017, with the replacement of seven front aluminum windows with wood windows at a cost of over $10,000, and earlier roof repairs were documented in 1983.

The property has also experienced some sidewalk-related issues between 2021-2024, including defects and tree root damage that lifted the sidewalk, with one of these cases remaining open as of August 2021. An administrative permit to verify the building's two-family dwelling use was completed in September 2023, confirming the property's current classification as a multi-family residential building.