Thousand Oaks Decibel Limits Rules (2026): What You Need to Know

Thousand Oaks Municipal Code Chapter 8.45 establishes an exterior noise ordinance with zone-based decibel limits that reflect the city's predominantly residential and suburban character in the Conejo Valley. For residential zones — which make up the majority of Thousand Oaks' land area — the permitted exterior noise level is 55 dBA during daytime hours (7 AM to 10 PM) and drops to 45 dBA during nighttime (10 PM to 7 AM). These measurements are taken at the property line of the receiving (affected) property. Commercial zones carry higher thresholds of 65 dBA daytime and 60 dBA nighttime to accommodate business activity.

Noise sources that exhibit a tonal character (pure tone hum, whine, or screech), an impulsive character (banging, hammering), or consist of clearly audible and repetitive music or speech may be assessed with an effective 5 dB downward correction, making the standard more stringent for those sources. The city's relatively low ambient noise baseline — Thousand Oaks lacks a major airport or freight rail and is set back from freeway noise corridors in many neighborhoods — means that violations of the nighttime 45 dBA limit are not uncommon in quiet residential areas. Ambient noise readings may be used to establish background levels in contested enforcement cases.

The Ventura County Air Pollution Control District (VCAPCD) holds concurrent authority over certain stationary industrial noise sources in the region. For disputes involving commercial HVAC systems, compressors, or other mechanical equipment at fixed facilities, VCAPCD can be contacted alongside city Code Enforcement. The city's Planning Division may impose project-specific noise mitigation conditions on commercial and industrial discretionary permits through the development review process.