3 rules for unincorporated Loudoun County, Virginia.
Verified from official government sources
Loudoun County setbacks vary dramatically by zoning district — from 10-15 ft in Planned Development districts (Ashburn, Brambleton) to 100+ ft in rural A-3 Agricultural zones west of Route 15. The Revised 1993 Zoning Ordinance (with 2023 amendments) governs. Typical suburban residential R-1: 40 ft front, 10 ft side, 25 ft rear. JLMA (Joint Land Management Area) and Rural Policy Area setbacks protect Loudoun's horse country character. Lot width and setback exceptions in cluster subdivisions. Variances require Board of Zoning Appeals hearing.
Loudoun County residential height limits typically 35 feet / 2.5 stories in R-1 and R-2 zones. Rural A-3 Agricultural allows 40 feet for primary dwellings, higher for silos and agricultural barns. PD-H (Ashburn, Brambleton) heights set by approved plan, often 35-40 ft. Commercial and industrial zones allow 60-75 ft. Data center zones (PD-IP, CLI) permit up to 90-100 ft for tall data centers. Measured from average finished grade to roof ridge. Dulles airport proximity imposes FAA Part 77 height limits regardless of zoning.
Loudoun County lot coverage limits vary by zone: R-1 residential typically 30% building coverage; PD-H (Ashburn, Brambleton) often 50-60% based on approved plan. A-3 Agricultural Rural has very low coverage (under 10%). Total impervious surface (buildings plus driveways and patios) may trigger stormwater management per Chesapeake Bay Preservation Area standards. PD-IP industrial (data centers) can approach 70-80% coverage. The Facilities Standards Manual supplements zoning with engineering standards.
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