Lee's Summit, MO Building Safety: Anti-Mansionization (2026)
Key Facts
- Size cap
- 1.5x average sq ft of block's existing homes
- Height cap
- average ridge height of block's most common story count
- Applies in
- R-1 blocks in Old Lee's Summit Area only
- Petition threshold
- 51% of parcel owners in proposed NSO boundary
- Appeal
- written appeal to Governing Body via City Clerk
- First-offense fine
- $10-$250 per day, UDO Sec. 1.170
Summary
In neighborhoods placed into a Neighborhood Stabilization Overlay, Lee's Summit caps a new single-family home at one and one-half times the average square footage of existing houses on the same block face, and limits ridge height to the average height of the block's most common story count. The Director reviews every plan before a building permit issues.
4.Height. Maximum building height shall be the average height, measured from the street grade to the highest point of the ridge line, of the most common single-family residential structure along the block frontage; i.e. if the most common structure is a single story, even though there may be several two storied structures along the block frontage, the average of the most common structure height shall be utilized.7.Structure size:a.Single story. The maximum area of a new single story residential structure shall not exceed one and one-half times the square footage size of the average of the single story residential structures along its block frontage, provided that the mass and scale is compatible with existing structures along the same block frontage.b.Multi-story. The maximum area of a new multi-story residential structure shall not exceed one and one-half times the square footage of the average of the multi-storied residential structures along the block frontage, provided the mass and scale is compatible with existing structures along the same block frontage.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 55 | Unified Development Ordinance: Supplement 15).
Full Breakdown
The Neighborhood Stabilization Overlay (NSO), created under UDO Article 5, Division V, responds to the Governing Body's finding that new single-family houses and additions incompatible with existing dwellings in established single-family neighborhoods are detrimental to neighborhood character, stability and livability (Sec. 440). An NSO can only be layered onto R-1 single-family blocks in the Old Lee's Summit Area, and only after a City-initiated petition or one signed by owners of at least 51 percent of the parcels in the proposed boundary (Sec. 470). Once designated, Sec.
5x ratio measured against the block's existing multi-story homes. Maximum building height is pegged to the average ridge height of whichever story count is most common on the block, so a block of mostly one-story houses caps new construction at that lower average even if a few two-story homes exist nearby. Garage size is limited to the size of garages already on the block unless none exist, front yard setback must fall within five feet of the block's average, and a two-story accessory building must sit at least ten feet off the rear line.
Every application requires a pre-application conference and photographs of neighboring houses documenting the block's existing pattern (Sec. 490); the Director's compatibility determination is final unless appealed in writing to the Governing Body (Sec. 500).
Violations & Fines
The Director's mass-and-scale review is a condition of the building permit itself: plans that exceed the 1.5x size cap or the block's average height are not approved until revised. Because the NSO sits inside the UDO, building or altering a house in defiance of an issued permit or a Director denial is a UDO violation under Sec. 1.170, a misdemeanor punishable by a fine of $10 to $250 per day for a first offense and $100 to $500 per day for repeat violations at the same address, plus possible ten-day jail terms.
Frequently Asked Questions
Does Lee's Summit limit how big a new house can be next to smaller older homes?
How does a neighborhood get an NSO in the first place?
What happens if a builder ignores the NSO height and size limits?
Sources & Official References
Other rules in Lee's Summit
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