Simi Valley, CA Noise Ordinances: Decibel Limits (2026)
Key Facts
- Outdoor limit
- 63 dB Ldn in outdoor living areas
- Indoor limit
- 45 dB Ldn in interior living areas
- Residential-to-residential rating
- STC 50 minimum
- Residential-to-commercial rating
- STC 60 minimum
- Late-night commercial use
- Barred 12 a.m.-6 a.m. without a CUP
- Applies to
- Mixed-Use (MU) Overlay District projects only
Summary
Development within Simi Valley's Mixed-Use (MU) Overlay District must meet numeric noise standards under SVMC Section 9-44.105(D)(12): 63 dB Ldn outdoors and 45 dB Ldn indoors. Projects meet those limits with minimum Sound Transmission Class ratings and an acoustical engineer's report, and commercial uses inside a mixed-use building cannot operate between midnight and 6 a.m. without a Conditional Use Permit.
12.Noise/vibration.a.The City noise standards are 63db Ldn in outdoor living areas and 45db Ldn in interior living areas. To comply with these standards, all new projects or additions to existing projects must meet the minimum Sound Transmission Class (STC) 50 rating set forth in the California Building Code between residential units in the same building and the minimum STC 60 rating between residential units and non-residential uses in the same building. Applicants for these projects must, under the direction of the Director of Environmental Services, prepare an acoustical analysis report (prepared by an acoustical engineer) describing the acoustical design features of the structure required to satisfy the exterior and interior noise standards. The report must include satisfactory evidence that the measures specified in the report(s) have been, or will be, incorporated into the design of the project.b.No commercial use within a mixed-use development shall be conducted between 12 a.m. and 6 a.m. unless approved with Conditional Use Permit.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 51).
Full Breakdown
105(D)(12)(a) sets the City's noise standards for the Mixed-Use Overlay District at 63 dB Ldn in outdoor living areas and 45 dB Ldn in interior living areas. To hit those numbers, every new mixed-use project, and any addition to an existing one, must meet a minimum Sound Transmission Class (STC) 50 rating between residential units within the same building, and a higher minimum STC 60 rating between residential units and any non-residential use sharing the building. Compliance is not self-certified: applicants must prepare an acoustical analysis report, authored by an acoustical engineer and reviewed under the direction of the Director of Environmental Services, documenting the specific design features used to hit the exterior and interior targets, with evidence those measures were or will be built into the project.
unless the City first approves a Conditional Use Permit for the extended hours. Because these standards sit inside the MU Overlay chapter, they apply specifically to mixed residential/commercial buildings within the Overlay boundaries, not to single-use commercial or residential development elsewhere in the city, which is instead governed by the citywide noise provisions found in Title 5 of the Municipal Code.
Violations & Fines
A mixed-use project that opens without the required STC ratings or acoustical report on file is out of compliance with its approved plans, and the Director of Environmental Services can withhold final building sign-off until the documented sound measures are verified as built. A commercial tenant operating between midnight and 6 a.m. without an approved Conditional Use Permit is operating in violation of Subsection (D)(12)(b) and can be cited or have its permit conditioned or revoked.
Frequently Asked Questions
What are the noise limits for new mixed-use buildings in Simi Valley?
Can a restaurant or bar in a mixed-use building stay open past midnight?
Do these decibel limits apply outside the Mixed-Use Overlay District?
Sources & Official References
Other rules in Simi Valley
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