Montgomery County, MD Noise Ordinances: Construction Hours (2026)
Construction hours in Montgomery County, MD, sometimes called construction noise rules or contractor work-hour ordinances, set when contractors can run power tools, hammers, and heavy equipment.
Key Facts
- Allowed hours
- 7 a.m.-5 p.m. weekdays only
- Noise cap (no plan)
- 75 dBA at 50 feet
- Noise cap (approved plan)
- 85 dBA with DEP suppression plan
- Off-hours standard
- 65 dBA day / 55 dBA night residential
- Enforcing agency
- Dept. of Environmental Protection
Summary
Construction noise in Montgomery County is capped at 75 dBA (85 dBA with an approved noise-suppression plan) between 7 a.m. and 5 p.m. weekdays; outside those hours the county's much stricter general noise limits apply instead.
A person must not cause or permit noise levels from construction activity that exceed the following levels: From 7 a.m. to 5 p.m. weekdays: 75 dBA if the Department has not approved a noise-suppression plan for the activity; or 85 dBA if the Department has approved a noise-suppression plan for the activity... The level specified in Section 31B-5 at all other times.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-90: Montgomery County Code contains legislation effective through May 7, 2026 | Zoning Updated Effective: April 13, 2026 | COMCOR Regulations effective as of July 1, 2026).
Full Breakdown
Montgomery County Code § 31B-6 sets a hard construction noise-level cap of 75 dBA from 7 a.m. to 5 p.m. on weekdays, rising to 85 dBA if the Department of Environmental Protection has approved a noise-suppression plan for the job. Outside that weekday daytime window, construction noise reverts to the county's general § 31B-5 limits -- 65 dBA daytime/55 dBA nighttime in residential noise areas, 67/62 dBA in non-residential areas -- which effectively rule out heavy equipment use nights, early mornings, and most weekend hours. Each violation of § 31B-6 is charged separately from any other noise violation arising from the same act.
Violations & Fines
A construction noise violation is a Class A civil violation -- up to $500 first offense, $750 repeat -- or a misdemeanor punishable by up to $1,000 and 6 months in jail; each day is a separate offense.
Frequently Asked Questions
Can construction happen on weekends in Montgomery County?
What if a contractor gets a noise-suppression plan approved?
Sources & Official References
Other rules in Montgomery County
How Montgomery County compares: Cities with the Strictest Construction Hours·Compare Montgomery County to another location·View the Maryland noise ordinances overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.