San Francisco Building Inspection Commission Codes § 1206.7

1206.7.1 Application. Residential structures located in noise critical areas, such as in proximity to highways, county roads, city streets, railroads, rapid transit lines, airports, nighttime entertainment venues, or industrial areas, shall be designed to prevent the intrusion of exterior noises beyond levels prescribed by the Municipal Code. Proper design to accomplish this goal shall include, but not be limited to, orientation of the residential structure, setbacks, shielding, and sound insulation of the building.

1206.7.2 Allowable interior noise levels. Interior noise levels attributable to exterior sources shall not exceed 45 dB in any habitable room. The noise metric shall be either the day-night average sound level (Ldn) or the community noise equivalent level (CNEL), whichever results in a higher measurement of noise level.

1206.7.3 Other noise sources. Residential structures to be located where the Ldn or CNEL exceeds 60 dB shall require an acoustical analysis showing that the proposed design will limit exterior noise to the prescribed allowable interior level. The Planning Department’s map titled Areas Potentially Requiring Noise Insulations, and similar maps and guidance produced by the Planning Department, shall be used where possible to identify sites with noise levels potentially greater than 60 dB.