Boulder County, CO Noise Ordinances: Construction Hours (2026)
Construction hours in Boulder County, CO, sometimes called construction noise rules or contractor work-hour ordinances, set when contractors can run power tools, hammers, and heavy equipment.
Key Facts
- Daytime construction limit (7am-7pm)
- 80 dB(A)
- Nighttime construction limit (7pm-7am)
- 75 dB(A)
- Applies to
- construction in residential areas
- Duration of limit
- life of construction permit
- Measurement point
- 10 ft from property line
- First-offense fine
- $30, rising to $300 max
Summary
Construction noise in residential areas of unincorporated Boulder County is capped at 80 dB(A) from 7 a.m. to 7 p.m. and drops to 75 dB(A) overnight, under Ordinance No. 92-28 Sec. 1.01.050(D). The stricter overnight cap runs for the whole life of the project's construction permit, or a reasonable completion period if none was set.
SECTION 1.01.050
Prohibited Noise Levels.
D. Construction projects in residential areas shall not exceed the following noise levels for the period within which construction is to be completed pursuant to any applicable construction permit issued by Boulder County, or if no time limitation is imposed, then for a reasonable period of time for completion of project:
7:00 a.m.-7:00 p.m. of the same day: 80 dB(A)
7:00 p.m.-7:00 a.m. of the following day: 75 dB(A)
E. Periodic, impulsive, or shrill noises are hereby declared unlawful when such noises are at or above a sound level of five dB(A) less than those listed in sections 1.01.050(A), (B), (C), and (D) above.
Full Breakdown
050(D) applies specifically to construction projects sited in residential areas, defined broadly under Sec. 020(A) to include single- and multi-family dwellings, high-rise apartment districts, motels and hotels with limited office space, plus schools, hospitals, nursing homes, parks, open space, and even undeveloped land next to a residential area regardless of its zoning. the next day. ' Sound is measured under Sec. 040(C): ten feet from the property line where the noise originates, or ten feet from the line/fifty feet from the source (whichever is less) if the source sits on government-owned public property, using an ANSI-standard A-weighted meter with wind under 5 mph (25 mph with a screen).
Sec. 050(E) additionally makes any periodic, impulsive, or shrill construction noise unlawful once it reaches just 5 dB(A) below these 80/75 dB(A) figures. None of the ordinance's general exceptions in Sec. 060, covering sanctioned events, emergency vehicles, or oil-and-gas operations under Title 34, carve out an extra allowance for ordinary residential construction beyond this table.
Violations & Fines
A construction crew exceeding the 80/75 dB(A) caps commits a Class 2 Petty Offense under Sec. 1.01.190, enforceable through the state's penalty assessment procedure (C.R.S. Sec. 16-2-201). The base fine is $30 per violation plus court costs, with a graduated schedule adding $30 for each repeat offense by the same contractor within a year, up to a $300 maximum.
Frequently Asked Questions
Can construction crews work loudly at night in unincorporated Boulder County?
How is construction noise measured for compliance?
What if there's no time limit on the construction permit?
What's the penalty for a construction noise violation?
Sources & Official References
Other rules in Boulder County
How Boulder County compares: Cities with the Strictest Construction Hours·Compare Boulder County to another location·View the Colorado noise ordinances overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.