Santa Clara County sets tiered decibel limits by zone: 55 dBA day and 45 dBA night in residential, 60/50 dBA in commercial, and 70/65 dBA in industrial areas, measured at the receiving property line.
The Santa Clara County Noise Ordinance (Division B11 of the County Code) establishes quantitative noise standards measured at the property line of the receiving parcel. Residential zones (R1, R2, RR) have daytime limits of 55 dBA (7:00 AM to 10:00 PM) and nighttime limits of 45 dBA (10:00 PM to 7:00 AM). Commercial zones allow 60 dBA day and 50 dBA night. Industrial zones allow 70/65 dBA. When noise originates in one zone but is received in another, the more restrictive receiving-zone limit applies. Short-duration impulsive noise (pile driving, gunshots) and tonal noise (humming compressors) receive a 5 dBA penalty adjustment in enforcement. Compliance is measured with a Type 2 sound level meter at the property line, five feet above grade. The County General Plan Noise Element uses Ldn/CNEL averages for land-use compatibility planning. Construction noise has separate rules allowing higher levels during permitted hours.
Contact your local code enforcement office for specific penalty information.
See how Santa Clara County's decibel limits rules stack up against other locations.
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