Prince William County, VA Noise Ordinances: Decibel Limits (2026)

Section 14-4(a)(1) of the Prince William County Code prohibits any sound above the Table 1 limits, which are expressed as Leq in A-weighted decibels. Residential and Mixed Use districts get 60 dBA in the daytime and 55 dBA at night. Commercial and Office districts get 65 dBA and 60 dBA. Industrial districts get 79 dBA and 72 dBA. An investigator measures at the property boundary of the sound source or at any point within a neighboring property that the sound reaches, and when the sound registers in more than one zoning district, the most restrictive classification controls.

Daytime under section 14-3 runs from 7:00 a.m. to 10:00 p.m. on weekdays and from 9:00 a.m. to 10:00 p.m. on Saturdays, Sundays and legal holidays observed by county government. Every other hour is nighttime.

A reading counts against you only if the limit is exceeded during three or more sampling intervals of at least 30 seconds each within one hour. A sound lasting less than 90 seconds waives the three-measurement requirement, and readings of impulsive sound or readings taken in response to nuisance complaints can be instantaneous Lmax readings. Section 14-7 requires a Type 1 integrating sound level meter, calibrated at the time of the measurement, and allows the microphone at any elevation, such as a second-floor bedroom window. Compliance is judged on the source sound level, which is the total level minus the ambient level.

Subsection (a)(2) exempts heating and cooling systems serving a residence, including air conditioners and heat pumps, and Radon systems from the nighttime Table 1 levels. Subsection (b) adds a separate limit for steady tonal sound, the hum, whine or buzz of HVAC units, transformers and backup generators: 73 dB(C) in the daytime and 68 dB(C) at night, measured at or within a residential property boundary in a residential district over a five-minute interval. The current text of section 14-4 took effect May 1, 2026 under Ord. No. 25-62.