Frederick, MD Noise Ordinances: Construction Hours (2026)

Section 15-21.2(b) sets a flat 90 dBA ceiling for construction or demolition site activity during daytime hours, then requires nighttime construction noise to meet the same Table 1 zoning-district limits that apply generally, meaning as low as 55 dBA at a receiving residential property between 10 p.m. and 7 a.m. Related exemptions in § 15-21.3(b) narrow how the limit applies: blasting operations for demolition, construction, mining, or quarrying are exempt only during daytime hours (subsection (4)); pile driving equipment is exempt only between 8:00 a.m. and 5:00 p.m. (subsection (9)); mobile agricultural field machinery used per manufacturer specifications is exempt (subsection (3)); and construction and repair work performed on public property is exempt outright (subsection (12)).

A contractor who cannot meet the 90 dBA daytime cap or the nighttime Table 1 levels can request a variance under § 15-21.4 by filing a written hardship request and advertising a public hearing, with the Mayor and Board of Aldermen able to grant relief for up to two years. Compliance is measured with ANSI Type II sound meters at the receiving property line under § 15-21.5, and a reading above these levels is prima facie evidence of a violation under § 15-21.6(a).