Kirkwood, MO Building Safety: Anti-Mansionization (2026)
Key Facts
- Lots ≤10,000 sq ft FAR
- 0.35 or 2,250 sq ft
- Lots 10,000-20,000 sq ft FAR
- 0.30 or 3,500 sq ft
- Lots ≥20,000 sq ft FAR
- 0.25 or 6,000 sq ft
- R-6 base FAR
- 1.5, with setback bonus
- R-6 absolute cap
- 12 stories or 125 feet
Summary
Kirkwood caps how large a single-family house can be relative to its lot through a sliding floor area ratio in Table 48-7, from 0.35 on lots of 10,000 square feet or less down to 0.25 on lots of 20,000 square feet or more.
Table 48-7 Floor Area Ratio for Single-Family Dwellings in Residential Zoning Districts1
Lot Area or District (square feet) Ratio Square Feet Whichever is Greater 10,000 or less 0.35 2,250 More than 10,000 but less than 20,000 0.30 3,500 20,000 or more 0.25 6,000
Full Breakdown
Section 25-48(e) of the Kirkwood Code of Ordinances controls house bulk on single-family lots through Table 48-7's floor area ratio (FAR) standard, the city's core defense against oversized 'mansionization' construction on modest lots. 35 times lot area or 2,250 square feet, whichever is greater. 25 ratio or 6,000 square feet, whichever is greater. This ratio applies on top of, not instead of, the lot coverage limits in Table 48-6 (25% to 40% of lot area depending on district and lot size) and the district height limits, so a house must satisfy both the footprint and the total floor area rule.
5 FAR cap applies, but a builder can earn one additional square foot of floor area for every square foot of yard left open beyond the required setbacks in Table 48-2, up to a hard ceiling of 12 stories or 125 feet. The finished first-floor height of new infill houses in R-3, R-4 and R-MM is likewise pegged to the average of neighboring houses under § 25-48(c)(3), reinforced by the FAR limit to keep new construction proportionate to its block.
Violations & Fines
Enforcement runs through the Director of Public Services under § 25-99, with appeal to the Board of Adjustment under § 25-25. Section 25-100(b) sets a first-offense fine of $10 to $250 per day the excess floor area remains, or up to 10 days' imprisonment, or both, rising to $100 to $500 per day for repeat violations at the same address; each day of noncompliance is a distinct offense under § 25-101.
Frequently Asked Questions
How does Kirkwood limit oversized new houses on small lots?
Does the floor area ratio replace Kirkwood's lot coverage limit?
Is there a different floor area rule for R-6 Planned Development?
Sources & Official References
Other rules in Kirkwood
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