Fountain Valley, CA Building Safety: Anti-Mansionization (2026)

Fountain Valley Municipal Code § 21.08.045 is the City of Fountain Valley's tool for limiting oversized homes in single-family neighborhoods. Table 2-3 sets the R1 floor area ratio at 0.55 plus a 0.08 bonus, and 0.5 plus 0.08 for the GH district. The bonus text says the allowable ratio can rise from 0.55 to a maximum of 0.63 only when specific design elements are built in, and it states that in no case may the ratio exceed 0.63.

The bonus table awards 0.02 when the second story façade is set back at least 10 ft directly behind the dominant first story façade and that setback portion is more than half the width of the house. Reducing the second-to-first story ratio to 60% and to 50% earns bonuses of 0.02 and 0.03, listed in that order. Adding 5 ft to the required side yard on both floors earns 0.01 per side yard, and varied roof lines, heights and pitches visible from adjoining streets earn 0.01. Owners of adjoining lots receive a mailed courtesy notice, and the planning/building director has ten days from receipt of plans to find that an unusual design feature would adversely affect a neighbor.

Other Table 2-3 rules limit bulk as well. For R1, floor area is calculated on living area only, so garage area is excluded, but a garage larger than 450 sq. ft. for two cars or 650 sq. ft. for three cars has the excess counted toward the ratio. Covered balconies, second story decks and courtyards with more than 50% of their perimeter walls enclosed also count. The second story is limited to 70% of the first story, and subdivisions of 5 lots or more have their ratios set by the commission.