270-280 5th St, San Francisco, CA 94107

The Mosso Apartments, located at 270-280 5th Street in San Francisco's South of Market neighborhood, is a multi-family residential building with 15 or more units, currently owned by Bprep Mosso Apartments LLC. The property has undergone significant maintenance and upgrades over the past several years, including a complete east lobby remodel and technology room upgrades in 2022 ($180,000), boiler replacements in 2023, and multiple fire safety system improvements in 2018 including the installation of additional sprinklers, fire alarms, and Ansul systems.

However, the building has experienced persistent heating and hot water system issues, with multiple tenant complaints in 2023-2024 documenting extended periods without heat or hot water, including a December 2023 incident where residents went without hot water and heat due to boiler problems. Recent inspections from 2024 have highlighted several maintenance concerns, including general dilapidation, damaged ceilings and walls, and kitchen appliance issues in units. The building's fire safety systems have also been a recurring concern, with multiple violations and complaints about sprinkler/standpipe systems and alarm systems between 2022 and 2025.

The property has undergone various plumbing and electrical upgrades, including the installation of fire backflow preventers and new electrical panels in 2017-2018, and most recently, the relocation of electrical outlets and lighting work in 2022. Current violations include an active complaint from October 2024 concerning incorrect standpipe inlet sizing, though many previous violations have been marked as abated. The building's recent history shows ongoing challenges with basic utilities and building maintenance, despite substantial investment in infrastructure improvements.