Novato, CA Noise from Specific Sources: HVAC & Mechanical Noise (2026)

The rule sits in Division 19.22 (General Performance Standards) of Chapter XIX of the Novato Municipal Code, the Novato Zoning Ordinance adopted by the Novato City Council. Section 19.22.020 applies the division to all new and existing land uses, permanent and temporary, in all zoning districts, and bars an existing use from being altered later to conflict with the standards. Section 19.22.040 lists air conditioners, antennas, filters, heating and ventilation equipment, pumps and transformers as examples of electrical and mechanical equipment.

Two tests apply. The first is a plain nuisance test: the equipment cannot be located and operated to disturb adjoining uses or activities. The second is a distance trigger. When a unit sits within 15 feet of a side property line in a residential zoning district, it must be sound attenuated to the maximum noise levels described in Table 3-5, and the method has to be acceptable to the Director.

Table 3-5 (Allowable Exterior Noise Levels) sets the residential limit at 45 dBA from 10 p.m. to 6 a.m. and 60 dBA from 6 a.m. to 10 p.m. Note (1) to the table reduces each limit by 5 dBA for impulse or simple tone noises, and if the ambient noise already exceeds the reduced standard, the ambient becomes the standard. Note (2) says the maximum levels cannot be exceeded for an aggregate period of more than three minutes within a one-hour period, or by more than 20 dBA at any time.

Section 19.22.070(C) fixes how the reading is taken: exterior noise is measured at the property line of the noise source, using a sound level meter on the A weighted scale at slow meter response, with fast response reserved for an impulsive noise.