Norwalk, CA Noise from Specific Sources: Generator Noise (2026)

150(H), one of the "Particular Acts" declared unlawful under Article III's noise chapter, targets the operation of any electric motor or engine whose starting or running is attended by sudden, loud or unusual noise. That covers portable generators, HVAC compressors and similar equipment. The code provides a specific safe harbor rather than an outright ban: the motor must be enclosed within a sound-insulated structure sufficient to prevent the noise from being plainly audible at a distance of 50 feet from that structure, and additionally, near housing, the noise cannot be plainly audible at all within 10 feet of any residence.

In practice that makes the standard tighter close to homes than the general 50-foot benchmark. 110 as work to restore property to a safe condition after a calamity, protect people or property from imminent danger, or utility service work, along with a public utility company's normal maintenance and construction activity, from Article III's noise requirements entirely. Outside those carve-outs, a homeowner or contractor running a loud, unenclosed generator is enforceable the same way as any other Article III violation, based on the noise reaching neighboring property rather than a fixed decibel reading.