The 2017 Baseline Mansionization Ordinance (LAMC §12.21.1, Ord. 187709) caps single-family residential floor-area-ratios between 0.40 and 0.50 of lot area, ending earlier bonuses and tightly limiting oversized homes in R1 hillside and flatland neighborhoods.
Effective March 17, 2017, Ordinance 187709 amended LAMC §12.21.1 and §12.03 to set a single-family Residential Floor Area (RFA) cap of 0.45 of lot size in standard R1 zones, 0.50 in RA, and 0.40 in many Hillside Construction Regulation areas. The ordinance eliminated the prior 20% green-building bonus and most attached-garage exemptions, counting covered patios and high-volume rooms toward RFA. Twenty-one Residential Floor Area Districts add stricter overlays as low as 0.30. Detached garages up to 400 sq ft and ADUs built under state law are still excluded. LADBS plan check enforces RFA before issuing building permits.
Building beyond the calculated RFA, mislabeling space as exempt, or failing to declare covered patios triggers stop-work orders, permit revocation, mandatory demolition of overage, and LADBS code-enforcement penalties.
Los Angeles, CA
R1 residential floor area is capped at 45% of lot area for lots under 9,000 sq ft, and 40% (or 4,050 sq ft, whichever is greater) for lots of 9,000+ sq ft un...
Los Angeles, CA
Setbacks in LA vary by zoning district under LAMC Chapter I. Typical R1 zone setbacks are 20 ft front, 5 ft side, and 15 ft rear. Hillside areas allow reduce...
See how Los Angeles's anti-mansionization rules stack up against other locations.
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