Broomfield, CO Noise from Specific Sources: Car Alarm Limits (2026)

Section 9-36-030 lists the sounds excused from the numeric dB(A) ceilings in Schedule 9-36A. Subsection (B) exempts any siren, whistle or bell lawfully used by emergency vehicles, or any other alarm system used in case of fire, collision, civil defense, police activity or other imminent danger, the category vehicle and burglar alarms fall under. That exemption comes with a built-in limit: the subsection expressly provides that burglar alarms not terminating within twenty minutes after being activated shall not be excepted, meaning an alarm still sounding 20 minutes after it goes off is treated as an ordinary noise violation subject to the full Schedule 9-36A limits, 55 dB(A) daytime and 40 dB(A) overnight in residential districts, 65/60 dB(A) in commercial districts, rather than being excused outright.

Section 9-36-050 separately addresses exhaust and muffler noise from motor vehicles, requiring a properly maintained muffler and banning cutout or bypass devices, and bars unauthorized air-compression 'jake brakes' within the city. Chapter 9-36 dates to Ordinance 862 from 1989, with the exceptions section amended by Ordinance 1249 in 1997 and Ordinance 1794 in 2005. No penalty is written specifically into Chapter 9-36, so a violation for an alarm running past the 20-minute cutoff is punished under the citywide general penalty in Section 1-12-020, a fine up to $2,650.00, imprisonment up to 364 days, or both.