738-740 20th Ave, San Francisco, CA 94121

The two-unit residential building at 738-740 20th Avenue in the Central Richmond neighborhood is a two-story flats and duplex structure built in 1923, currently owned by Aidan J. O'Sullivan and Thao Bui. The property underwent significant renovations in 2016-2018, including comprehensive structural improvements such as wall removals, beam replacements, and installation of shearwalls for voluntary strengthening, followed by window replacements with aluminum clad wood double hung windows.

Major plumbing upgrades were completed in early 2017, including new water service installation, sewer line work, and extensive bathroom and kitchen remodeling across both units, along with the installation of a radiant heating system. The electrical system was modernized with new wiring throughout, and in September 2018, a residential solar system with 28 PV modules (10.08 kW) was fully installed, following earlier infrastructure preparations in 2017. The building's maintenance history shows active upkeep, including a complete reroofing project in 2017 costing $12,100, and the installation of new gas fireplaces in early 2017.

The property has had minimal negative incidents recorded through 311 calls, primarily involving parking violations and street cleaning issues, with the most recent being a garbage and debris complaint in July 2024. A notable event in the building's history was a tenant buyout at 740 20th Avenue in October 2016, for $71,200 involving one tenant. The extensive renovations and upgrades completed between 2016-2018 suggest proactive maintenance and modernization of the property, particularly with regard to safety improvements and energy efficiency through solar panel installation.