1671-1673 20th Ave, San Francisco, CA 94122

The property at 1671-1673 20th Avenue in San Francisco's Central Sunset neighborhood is a two-unit, two-story multi-family residential building constructed in 1924. The most significant recent modification occurred in 2002-2003, when a substantial vertical addition was completed, including the construction of a third floor and penthouse, along with electrical upgrades comprising rewiring work including 5 switches, 10 lights, and 5 receptacles.

The building has undergone several important improvements over the years, including garage modifications and the addition of a basement kitchen in the late 1980s, bathroom installations in the garage during the mid-1980s, and termite repairs in 1997. Of particular note is a housing inspection complaint filed in February 2010 regarding a possible illegal unit on the ground floor with shared entrance, kitchen, and bathroom facilities, though this complaint was marked as "Not Active" by September 2010.

The property has experienced various infrastructure challenges based on 311 calls, particularly concerning pavement defects near the property, with reports filed in 2019, 2020, and most recently in April 2024. Other community-related incidents in the vicinity include occasional noise complaints, waste reports, and parking concerns, all of which were handled through appropriate city channels.