Showing ordinances that apply to Lexington, MA
Lexington is an unincorporated community (population 34,454) in Middlesex County, Massachusetts. Because Lexington is not an incorporated city, it does not have its own municipal code. Instead, Middlesex County ordinances apply directly to properties here. The hvac & mechanical noise rules below are the ones that govern your area.
HVAC equipment in Middlesex County must meet MassDEP 310 CMR 7.10 and local dBA limits. Most communities enforce 55 dBA at property lines at night, often requiring setbacks or sound barriers.
Residential and commercial HVAC units across Middlesex County are regulated under MassDEP 310 CMR 7.10 and local noise ordinances. The key rule: HVAC equipment cannot raise ambient noise more than 10 dBA at the neighboring property line. In practice, most modern mini-splits, heat pumps, and condensers operate at 55 to 65 dBA at one meter, meaning proper placement and setbacks keep them compliant. Cambridge, Newton, and Lexington require HVAC units to sit at least 5 to 10 feet from property lines; some towns require acoustic fencing or enclosures if units face a neighbor's bedroom window. Commercial rooftop units in Somerville and Waltham need sound study review during site plan approval. New construction and heat pump retrofits funded through Mass Save often need installer certification that placement meets local noise rules. Complaints go to the board of health or building department.
Contact your local code enforcement office for specific penalty information.
See how Lexington's hvac & mechanical noise rules stack up against other locations.
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