This is not a local code requirement, this is the California Building Code. San Francisco never adopted the IRC.
Mark Hogan
A single local building code amendment apparently raised the cost of legalizing two ADUs by a million dollars.
Under CA's Residential Code, "habitable spaces like bedrooms must have ceiling heights of at least 7 feet, which Roberts’ two studios do." But SF's code requires "7 feet, 6 inches." 🎁link:
A woman whose bureaucratic battle was detailed by the Chronicle has won a city contest targeting outdated regulations — and may finally see reform.