909 Wisconsin St, San Francisco, CA 94107

The 4-unit, 3-story multi-family residential building at 909 Wisconsin St in Potrero Hill, owned by Prosek Family Trust, has undergone several significant renovations since its construction in 1912. The most substantial work occurred between 2003-2011, when major improvements included new front and back stairs, security enhancements, electrical system upgrades, and plumbing improvements, with a total investment exceeding $200,000. Importantly, the building faced serious heat-related issues in 2003-2004, with multiple complaints about lack of heat during specified hours, which were eventually resolved by September 2011.

Several safety violations were documented during this period, including problems with fire safety equipment, security locks, and a missing second means of egress for the third-floor unit, though these were all addressed by September 2011. More recently, the building has experienced multiple sewer-related issues, with the most recent incidents occurring in late 2024 involving sewage backups and lateral repairs, including a significant 26-foot replacement of the lower lateral line. The building underwent a routine safety inspection in 2015, and there was an investigation of an allegedly illegal third-floor unit in 2004, which was resolved in 2011. Past improvements included electrical upgrades throughout all units, new heating systems, and various building maintenance projects.

The property has also required attention to security features, including installation of proper deadlatch locks and window repairs, all of which were addressed through completed permits and inspections. Recent maintenance history shows the building's basic systems have been regularly addressed, though the frequency of recent sewer-related calls suggests ongoing infrastructure challenges. The property has received several permits for various improvements over the years, including a 1988 project for insulation, gutters, and siding work, and a cancelled permit from 1986 for a proposed third-floor deck. The most recent building permits indicate routine maintenance and inspection activities rather than significant structural changes, suggesting the major renovation period from 2003-2011 addressed most of the building's critical systems and safety requirements.