San Francisco Decibel Limits Rules (2026): What You Need to Know

San Francisco's approach to decibel regulation is a hybrid system combining specific numerical limits for fixed mechanical equipment with a subjective reasonableness standard for general noise. The SF Police Code Article 29, Sections 2909 and 2910, and the SF Health Code Article 29 establish that noise from fixed mechanical equipment — including HVAC systems, rooftop condensers, exhaust fans, generators, and similar installations — must not exceed 45 dBA or 50 dBC inside any neighboring dwelling unit with windows and doors closed. At the property line, equipment noise must not exceed the ambient noise level by more than 5 dBA.

These standards are especially significant in San Francisco because of the density of construction and the proximity of commercial and residential uses. Rooftop HVAC units on commercial buildings frequently abut residential windows just a few feet away, and basement mechanical rooms in mixed-use buildings transmit low-frequency vibration through shared structural elements. The Department of Building Inspection (DBI) reviews mechanical equipment installations for noise compliance during the permitting process, and the Department of Public Health (DPH) Environmental Health Branch investigates complaints about equipment noise that exceeds standards.

For noise sources not covered by the fixed-equipment standards — such as parties, music, vehicle noise, and general neighborhood disturbances — the city relies on the subjective standard under Article 29 that prohibits unnecessary, excessive, or unusually loud noise. This dual framework means that while equipment noise can be measured and enforced quantitatively, most residential noise complaints are resolved through the qualitative disturbance-of-the-peace standard.