474 18th Ave, San Francisco, CA 94121

The two-unit residential building at 474 18th Avenue in San Francisco's Central Richmond district is a two-story flats and duplex structure built in 1920, currently owned by the Hanako Fujimoto Revocable Trust. The property has undergone several significant improvements over its history, with the most recent notable work being a street space permit issued in 2012.

The building's roof was replaced in 2003 at a cost of $8,500, representing a substantial maintenance investment. There has been consistent attention to window upgrades over the years, with three separate window installation projects recorded: in 1998, five replacement windows were installed in the rear of the building; in 1996, four windows were added to rear bedrooms and the kitchen; and back in 1985, aluminum windows were installed in existing frames.

It's worth noting that the 1998 and 1996 window permits are listed as expired, though these projects appear to have been completed based on historical practices of the time. The building's maintenance record shows regular improvements to basic systems and features, particularly focusing on energy efficiency and weatherproofing through window and roof upgrades.