San Diego County, CA Building Safety: Anti-Mansionization (2026)
Key Facts
- Purpose
- compatibility of scale between buildings
- Designator unit
- numeral = thousands of sq ft
- Dash designator
- no floor-area cap, setbacks/height apply
- Jurisdiction
- unincorporated San Diego County only
- Set where
- each zone's Development Regulations table
Summary
Unincorporated San Diego County limits a building's total floor area under the Zoning Ordinance's Maximum Floor Area designator, set zone by zone to keep new construction in scale with existing buildings nearby.
The provisions of Section 4400 through Section 4499, inclusive, shall be known as the Maximum Floor Area Regulations. The purpose of these provisions is to limit the total floor area of individual buildings in order to assure compatibility of scale between buildings on the same building site and between buildings on different building sites within the same zone. 4405 MAXIMUM FLOOR AREA DESIGNATOR NOTATION. Maximum floor area permitted per building shall be indicated by an Arabic numeral, with square feet expressed in thousands, e.g., "2" and "4" indicating "2,000" and "4,000" square feet, respectively; and hundreds expressed as a decimal fraction, e.g., "2.5" and "4.2" indicating 2,500 and 4,200 square feet, respectively. A dash ("-") shall indicate that permitted floor area is not regulated except as may otherwise be limited by required setbacks and height restrictions or that when used in conjunction with a Village Zone, regulations shall be specified in the applicable Village Zone Development Regulations. (Amended by Ord. No. 8581 (N.S.) adopted 9-20-95) (Amended by Ord. No. 10348 (N.S.) adopted 7-30-14) 4410 MAXIMUM FLOOR AREA DESIGNATORS PERMITTED. Maximum floor area designators shall be established to limit the floor area of individual buildings and any such floor area may be specified within the Development Regulations. **** FLOOR-AREA RATIO REGULATIONS **** 4500 TITLE AND PURPOSE. The provisions of Section
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-141: Administrative: Current through Ord. No. 11007 (N.S.), effective 7-10-26 | Regulatory: Current through Ord. No. 11008 (N.S.), effective 7-24-26).
Full Breakdown
Zoning Ordinance §§ 4400-4410 create the Maximum Floor Area Regulations, capping the total floor area of individual buildings on a lot in unincorporated county territory. Each zone's Development Regulations table carries a designator: an Arabic numeral in thousands of square feet ("2" means 2,000 square feet, "2.5" means 2,500) sets the cap for that zone, expressly to keep new houses in scale with buildings on the same site and on neighboring lots in the same zone. Where the table shows a dash instead of a number, that zone has no separate floor-area cap and building bulk is controlled only through setback and height limits.
Violations & Fines
Exceeding a zone's Maximum Floor Area designator without an approved variance can draw plan-check rejection, a stop-work order, or a zoning code violation from Planning & Development Services.
Frequently Asked Questions
Does San Diego County cap how big a house can be?
Does this floor-area limit apply in the City of San Diego?
Sources & Official References
Other rules in San Diego County
California rules heatmap·Compare San Diego County to another location·View the California building safety overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.