Montgomery County limits lot coverage (the percentage of a lot covered by buildings and impervious surfaces) based on the zoning classification. In the R-200 zone, lot coverage is capped at 25 percent. Higher-density zones allow greater coverage, and environmental regulations add further restrictions.
Montgomery County Zoning Ordinance Chapter 59 establishes maximum lot coverage for each residential zone. The R-200 zone limits total lot coverage to 25 percent of the lot area. The R-90 zone allows up to 35 percent coverage. The R-60 zone permits up to 35 percent as well. Lot coverage includes all buildings, accessory structures, driveways, patios, and other impervious surfaces. The Forest Conservation Law (Chapter 22A) may impose additional restrictions on properties with significant tree cover, requiring preservation of forest areas that further limits buildable area. Properties within Special Protection Areas for watersheds also face impervious surface limitations to protect water quality. The Department of Permitting Services calculates lot coverage as part of building permit review. Stormwater management regulations under Chapter 19 may require on-site retention or rain gardens when impervious surfaces exceed certain thresholds.
Exceeding lot coverage limits is a zoning violation. DPS can deny permits for projects that would exceed coverage. Unpermitted impervious surfaces may require removal or mitigation with stormwater management features.
Montgomery County, MD
Montgomery County Code §31-14 prohibits parking heavy commercial vehicles (over 10,000 lbs, 21+ ft, 8+ ft high) on public residential roadways. One light com...
Montgomery County, MD
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Montgomery County, MD
Maryland has no shared fence cost statute. Each owner responsible for their own fence. Spite fence provision under MD RP Art. §14-120.
Montgomery County, MD
Montgomery County prohibits barbed wire, razor wire, and electric fences in residential zones under Ch 59. HOAs commonly restrict chain-link fencing. Approve...
Montgomery County, MD
Maryland’s Tracey’s Law (2014) treats all dog breeds equally under negligence standard. No breed-specific strict liability. Dangerous dogs behavior-based.
Montgomery County, MD
Montgomery County requires dogs on leash in public. Off-leash in designated parks only. Rabies vaccination required statewide. MD Criminal Law §10-619 covers...
See how Montgomery County's lot coverage limits rules stack up against other locations.
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