O'Fallon, MO Zoning Overlays & Bonuses: Downtown Design Guide (2026)
Key Facts
- Max height
- 50 ft / 3 stories, up to 6 with approval
- Min. green space
- 20 percent of lot
- Neighbor notice
- 7 days before hearing
- Parking shortfall fee
- $1,700 plus land cost per space
- Minimum lot area/coverage
- none required
Summary
O'Fallon's Downtown Overlay District, City Code § 400.163, relaxes the standard zoning code to encourage redevelopment: buildings can rise to fifty (50) feet or three (3) stories (six with Planning and Zoning Commission approval), only twenty percent (20%) of the lot must stay green space, and neighbor notice is required before any site plan is approved.
C. Building/Structure Height. No building or structure should exceed fifty (50) feet or three (3) stories. The Planning and Zoning Commission and City Council may allow additional height to a maximum of six (6) stories when it is determined that: 1. The building heights are in appropriate scale to their surroundings both internal and external to the site. 2. Building design and orientation effectively preserve clearly identified significant view corridors from and through the development site. 3. The applicable fire protection district can provide the necessary emergency fire protection and emergency access. 4. The building height will not interfere with St. Charles County's emergency microwave communications system. ... E. Lot Coverage Requirements. There are no lot coverage requirements in this District except that a minimum of twenty percent (20%) of the lot shall be landscaped green space.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4860992; v58 updated 2026-05-14; through 05-14-2026).
Full Breakdown
163 creates the Downtown Overlay District to "recognize the unique and historic attributes of the area identified as Downtown on the Official Zoning District Map" and to give developers more design flexibility than the underlying zoning allows. 163(A)(1) requires the Planning and Development Department to identify and mail notice to every abutting property owner at least seven (7) days before the Planning and Zoning Commission meeting on a site plan, and to post a sign at least six (6) square feet in size on the property for the same period.
163(C), though the Commission and City Council may approve up to six (6) stories if the added height is in scale with its surroundings, preserves view corridors, and won't interfere with fire access or St. Charles County's emergency microwave communications system. 163(E) requires "a minimum of twenty percent (20%) of the lot" to remain landscaped green space. 163(F), (G)). 00) plus land cost per parking space" below the minimum, funding City-maintained public parking downtown.
Violations & Fines
Development that skips the required neighbor notice, exceeds the height cap without Commission approval, or falls short of the 20% green-space minimum violates § 400.163 and Chapter 400 generally. As a zoning violation under the City's general penalty, § 100.010(A)(4) applies the RSMo §§ 89.120/89.490 schedule: up to $200 for a first offense in twelve months, rising to $450 for a fourth.
Frequently Asked Questions
How tall can a downtown O'Fallon building be?
Do downtown O'Fallon developments need a minimum amount of green space?
What if a downtown project can't fit all its required parking on-site?
Do neighbors get notice before a downtown site plan is approved?
Sources & Official References
Other rules in O'Fallon
Compare O'Fallon to another location·View the Missouri zoning overlays & bonuses overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.