4431-4433 20th St, San Francisco, CA 94114

The property located at 4431-4433 20th Street is a two-unit, two-story multi-family residential building constructed in 1900 in the Eureka Valley/Dolores Heights neighborhood, currently owned by Christopher M Jablonski. The building has undergone significant modernization and safety improvements over the past several years, with a comprehensive renovation program including the recent completion of reroofing (2024) and the installation of a new automatic fire alarm system (2023).

Notable safety upgrades include the installation of a sprinkler system (2021) and associated monitoring systems, with all fire protection work completed in accordance with applicable codes. The building underwent substantial interior improvements in 2020-2021, including kitchen and bathroom remodels in both units, the legalization of unauthorized living spaces, and the addition of a first-floor ADU (Accessory Dwelling Unit) with a garage conversion. The property has experienced some regulatory scrutiny, particularly regarding unauthorized construction and potential short-term rental violations in 2019, when a complaint investigation revealed unpermitted modifications including a full bathroom, sitting room, office, and bedroom.

This issue was later addressed through proper legalization procedures and permits, including seismic strengthening work (2021) and updates to the building's infrastructure. The building's systems have been upgraded to modern standards, including a 400A electrical service upgrade (2022) and the installation of Mitsubishi heat pump systems for both units (2020). Recent history shows ongoing parking management issues in the vicinity, with multiple enforcement actions taken between 2022 and 2024, though these are external to the building itself.