Loudoun County, VA Noise Ordinances: Industrial Noise (2026)

Industrial noise in unincorporated Loudoun County is regulated through two parallel tracks. The zoning track is Section 5-1507 of the Loudoun County Zoning Ordinance (Article 5, Additional Regulations and Standards). Subsection (A) declares the purpose of protecting citizens from excessive sound, and subsection (E) sets the operative numeric limits in Table 5-1507(E): no use may produce sound that, measured at the property line of the receiving development, exceeds 55 dBA where the receiving use is residential, 60 dBA where it is mixed-use, 65 dBA where it is commercial, civic, or institutional, and 70 dBA where it is industrial. The maxima apply unless a stricter, use-specific decibel level is fixed elsewhere (Section 5-600 et seq., Additional Regulations for Specific Uses). The criminal track is Chapter 654 of the Codified Ordinances of Loudoun County. Section 654.02 (Excessive Sound in Residential Areas and Dwellings), re-enacted September 1, 2016 after the Virginia Supreme Court struck down the prior version as unconstitutionally vague, makes it unlawful to permit any source of sound to be 'audible and discernible' inside another person's residential dwelling with the doors and windows closed. The chapter also lists specific prohibited acts including engine racing, unmuffled exhaust, sound-reproduction devices audible at 100 feet, and continuous vehicle alarms longer than 20 seconds. Data centers receive a third layer of standards under ZOAM-2024-0001, approved by the Board of Supervisors on March 18, 2025, and the Phase 2 amendments now being drafted under the Data Center Standards and Locations project (Phase 2 adoption anticipated December 2026). Data centers are no longer a by-right use; they require Special Exception (SPEX) approval in the IP (Industrial Park), GI (General Industry), and MR-HI (Mineral Resources-Heavy Industry) districts. Where a data center is proposed adjacent to residentially zoned property, the amendments require expanded building setbacks, a six-foot earthen berm with enhanced landscape buffer on top, full screening and soundproofing of roof-top and ground-mounted mechanical equipment, fully-screened refuse and generator yards, limited hours for backup-generator testing, and a pre-construction acoustical study plus a post-construction verification study demonstrating compliance with Section 5-1507. The application package for a data center SPEX must therefore document not just the A-weighted property-line level but also tonal and low-frequency content from chillers, transformers, and emergency generators - the components residents most often cite in complaints.