Arcadia, CA Building Safety: Anti-Mansionization (2026)

Arcadia controls oversized houses with a maximum floor area schedule in Table 2-2 of § 9102.01.030, which applies outside homeowners associations identified by City Council Resolution. North of Huntington Drive the cap is 45% of lot area up to 7,500 sf, then 3,375 sq ft plus 40% of lot area over 7,500 sq ft for lots of 7,501-10,000 sf, 4,375 sq ft plus 35% over 10,000 sq ft, 6,125 sq ft plus 25% over 15,000 sq ft, 7,375 sq ft plus 20% over 20,000 sq ft, and 9,375 sq ft plus 15% over 30,000 sq ft for lots of 30,001 sf or more.

South of Huntington Drive it is 45% up to 10,000 sf, then 4,500 sq ft plus 40% over 10,000 sq ft, 6,500 sq ft plus 30% over 15,000 sq ft, 8,000 sq ft plus 25% over 20,000 sq ft, and 13,000 sq ft plus 32% over 40,000 sq ft. Table 2-3-1(1) sets tighter ratios in named associations: Santa Anita Village and Highland Oaks are 35% of lot area below 10,000 sf, Lower Rancho and Santa Anita Oaks are 37%, and Upper Rancho matches the south-of-Huntington schedule at 45%.

A one-story house gets 3% of lot area in additional floor area everywhere. Section 9103.01.030 counts the main dwelling, detached accessory structures, accessory dwelling units, garage area, enclosed patios, and high volume ceilings (all interior areas above 14 feet). Required parking is excluded: 450 square feet for a two-car garage and 650 for a three-car garage on houses under 5,000 square feet, and up to four spaces (850 square feet maximum) on larger houses. Basements and non-enclosed covered patios, porches, decks, and balconies are excluded.

Other massing controls apply too: two stories maximum, roof decks not permitted in R-M, R-0 and R-1, and no vertical or architectural elements above the primary entrance that emphasize the scale and massing of the structure.