1657-1659 Mason St, San Francisco, CA 94133

The two-unit residential building at 1657-1659 Mason Street in Russian Hill, owned by GDS Properties LLC, was constructed in 1907 and spans two stories. The property has undergone significant renovations in recent years, with major work starting in 2022 including comprehensive interior improvements valued at $350,000 encompassing electrical systems, finishes, fixtures, HVAC, and the addition of a proposed roof deck with safety railings. This renovation phase also included the replacement of 45 windows (27 street-facing and 18 rear-facing).

Plumbing upgrades were substantial, with installations for complete utilities including two water heaters, kitchen appliances, and a new furnace and ductwork system. The property has maintained active building maintenance, including a roof replacement in 2014 and earlier rock fall protection work in 2005. Recent concerns have emerged regarding construction practices, with a lead paint complaint filed in April 2023 about improper containment during renovation work, though this case is currently not active.

A significant proposed development is currently under review that seeks to add two additional residential units to the property, incorporating a three-story structure over an existing concrete garage, with a combined proposed area of approximately 9,239 square feet. This addition, being pursued through a discretionary review process, would not increase the building's height or unit count, though it represents a substantial expansion of the property's footprint. The building's maintenance record shows regular upkeep and modernization efforts, including electrical system upgrades in 2023, though there have been some minor neighborhood issues addressed through 311 calls, such as sidewalk defects and occasional graffiti.