509 Potrero Ave, San Francisco, CA 94110

The property at 509 Potrero Avenue is a two-story, three-unit multi-family residential building constructed in 1911, currently owned by the Mark R Sidmore Living Trust. The building has undergone several significant renovations over the past decade, most notably a comprehensive interior remodel in 2013 of the rear cottage that included new stairs, foundation work, and bathroom additions costing $108,000. A major electrical and plumbing upgrade was performed in 2010-2013, including complete rewiring and plumbing replacement in all units, installation of new electrical panels, and updates to bathroom and kitchen facilities, with a total estimated cost exceeding $100,000.

The property experienced a notable fire incident in 2009 that affected the top floor and garage, requiring extensive repairs and system replacements throughout the building. More recently, there have been recurring sewage issues, with multiple sewer backup incidents reported between 2020 and 2023, indicating potential ongoing plumbing system challenges. Most recent plumbing work includes a house trap replacement completed in September 2024.

The building has also had several street space permits issued between 2009 and 2016, and there have been various 311 calls related to the property, primarily concerning general cleaning and garbage issues. While some exterior improvements were made in 2012, including stairway and deck replacements, these were initially performed without proper permits, though they were subsequently legalized through the permitting process. The property has maintained active compliance with required inspections and permits since the fire incident, though the recurring sewer issues suggest ongoing infrastructure maintenance needs.