Thornton, CO Noise Ordinances: Construction Hours (2026)
Construction hours in Thornton, CO, sometimes called construction noise rules or contractor work-hour ordinances, set when contractors can run power tools, hammers, and heavy equipment.
Key Facts
- Curfew
- 9:00 p.m. to 6:00 a.m., citywide
- Daytime standard
- Industrial dB limits, 6 a.m.-9 p.m.
- Industrial districts
- No curfew, Table A limits apply
- Priority-project exception
- 400+ feet from occupied home
- Governing section
- City Code § 38-441(c)(5)
Summary
Thornton bans construction activity noise citywide between 9:00 p.m. and 6:00 a.m., except in industrial districts or on priority-review projects at least 400 feet from an occupied home. Daytime construction between 6:00 a.m. and 9:00 p.m. must still meet the industrial-district sound limit under § 38-441(c)(5).
(5)Construction activities as defined in Section 38-1 are subject to the following requirements:a.Construction activities are prohibited within any zoning district between the hours of 9:00 p.m. and 6:00 a.m. unless specifically authorized in paragraph (5)c or (5)d, below.b.Construction activities occurring between 6:00 a.m. and 9:00 p.m. shall comply with the sound pressure level limits for industrial districts given in subsection (c), Table A.c.Construction activities in industrial districts are allowed at all times of the day, subject to the sound pressure level limits for that district in subsection (c), Table A .d.Construction activities associated with the development of property that has been authorized for administrative review for priority projects in Section 18-38 of the Code, and which are located at least 400 feet from an occupied dwelling unit, may occur at any time of day and shall comply with the sound pressure level limits in subsection (c), Table A.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 65).
Full Breakdown
unless one of two exceptions applies. The first exception, subsection c, allows construction at any hour in industrial districts, subject to that district's sound pressure limit from Table A (80 dB(A) day, 75 dB(A) night). The second, subsection d, allows around-the-clock construction on property authorized for administrative review as a priority project under Section 18-38, but only if the work site sits at least 400 feet from an occupied dwelling unit, and even then it must still meet Table A's limits. , ordinary construction activity is not restricted by a curfew but must comply with the sound pressure level limit for industrial districts (the least restrictive tier) rather than the tighter residential limits.
The purpose section, § 38-440(a)(4), states these noise rules are comprehensive and "supersede any hours of delivery that are specified in any other ordinance or resolution," and emergency abatement work is excluded entirely from the noise article under § 38-441(b)(1).
Violations & Fines
Violating the construction curfew is grounds for an immediate summons and complaint under § 38-452(d), or a written notice to abate giving the contractor or owner no less than 24 hours and no more than 5 days to stop the violation. The notice must be signed by the city manager and delivered personally, by certified mail, or posted on the property if delivery fails.
Frequently Asked Questions
What time can construction noise start in Thornton?
Is overnight construction ever allowed in Thornton?
Does Thornton's construction noise rule override delivery-hour restrictions?
Sources & Official References
Other rules in Thornton
How Thornton compares: Cities with the Strictest Construction Hours·Compare Thornton to another location·View the Colorado noise ordinances overview
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