56 Mars St, San Francisco, CA 94114

56 Mars Street is a two-unit, two-story multi-family residential building located in Corona Heights and owned by Mars Place LLC. Built in 1900, this flats and duplex structure has undergone several significant renovations, with the most recent being a proposed horizontal addition of 670 square feet above both units, particularly affecting 56A, which would increase its living space from 475 to 1,135 square feet. This addition, with an estimated cost of $367,835, was issued a permit in May 2022 and appears to be the most substantial current improvement project.

The building underwent major improvements in 2010, including extensive foundation work, lower-level modifications, and comprehensive updates to both units' kitchens and bathrooms, with associated electrical and plumbing upgrades totaling over $100,000. These renovations were initially the subject of a complaint in January 2010 regarding lack of proper inspections, though this violation was abated by April 2010. The property has maintained compliance with building codes since then, with subsequent improvements including electrical rewiring, plumbing upgrades including new bathrooms and kitchens, and a central heating system installation.

Recent maintenance issues have mostly been external to the building itself, including some 311 calls regarding parking violations and street conditions between 2013 and 2024. Notably, there were two sewage backup incidents recorded in 2015, though these were resolved as per the PUC Sewer Operations records. The building appears to be well-maintained, with most recent issues being routine municipal concerns rather than building-specific problems.