423-431 Union St, San Francisco, CA 94133

The building at 423-431 Union Street in Telegraph Hill is a three-story multi-family residential structure built in 1906, currently owned by the Gilbert Family 1991 Trust. The property, originally consisting of 6 units, has undergone significant modernization and safety improvements over recent years, including comprehensive fire safety upgrades. Most notably, in 2024, the building received a new fire alarm system and underwent a major fire sprinkler installation project covering the basement and new ADUs on the first floor.

The building is in compliance with the San Francisco Mandatory Soft Story Retrofit Program, having completed required seismic upgrades in 2024, which included soft-story retrofit work at the basement level and ADA improvements to the first-floor retail space. Recent improvements also include HVAC upgrades, with the installation of new high-efficiency furnaces and heat pumps throughout the building. The property has experienced some maintenance and safety issues in the past, including lead paint concerns documented in complaints from 2013-2014, which were subsequently addressed.

A 2022 complaint regarding garbage area access was resolved, and there have been several 311 calls regarding debris and cleaning issues near the property, most recently in 2024. The building underwent substantial renovation work in 2020-2023, including the removal of non-permitted units and conversion of commercial space into additional residential units, bringing the total to 8 residential units. This extensive work also incorporated new plumbing and electrical systems, with permits showing ongoing maintenance and system upgrades throughout 2023-2024. The most recent inspections and permits indicate that the property is actively maintaining compliance with current building codes and safety requirements, with all major outstanding issues having been addressed or resolved.