O'Fallon building department

O’Fallon’s Building Division does plan review and inspections for new homes and commercial buildings. It also maintains the building codes the city has adopted and runs the residential rental occupancy program. The division works from the second floor of the O’Fallon Municipal Centre (City Hall) at 100 North Main Street. City Hall is open Monday–Friday, 8:30 a.m.–4:30 p.m.

Which office handles your permit

O’Fallon divides permits among three offices. The city lists them like this:

Office	Phone	Permits handled
Building Division	(636) 379-5660	Fences, decks, porches, sunrooms, patio covers, pergolas, sheds, pools and hot tubs, retaining walls, water heaters, HVAC replacement, additions, basement finishes, solar panels, fire/wind/impact damage repair, structural changes, new buildings, garages, change of use, demolition
Planning Division	(636) 379-5544	Temporary structures, dumpsters, signs
Engineering Department	(636) 379-7630	Grading and land disturbance, driveways

Plumbing permits cover sewer laterals, water service lines and lawn irrigation. A rental occupancy permit is required before anyone moves into a rental unit.

Re-roofing

The city’s residential re-roofing guide is dated May 16, 2017. It says that re-covering or replacing asphalt shingles on one- and two-family homes and townhouses does not need a permit. The work still has to meet the adopted residential code and the manufacturer’s instructions. One rule from the guide: all existing layers have to be removed down to the sheathing. The exception is a roof with a single layer over a sound, dry base.

Applying in CitizenServe

O’Fallon handles permits, business licenses and code-enforcement complaints on CitizenServe. Register for a free account first. You can then apply, upload documents, pay fees, track review progress and schedule inspections. Each permit type has its own submittal checklist in the portal’s guides section. The city also posts a contractor project signature sheet and a supplemental agreement for basements with rooms that have no egress.

When an illuminated sign is wired, the electrical contractor signature sheet must carry a St. Louis County or St. Charles County license number.

Fees

The city’s Commercial and New Home Permit Fees schedule covers new homes and commercial buildings. For those, the fee is gross area × square-foot construction cost × 0.0065. Most smaller permits are construction cost × 0.0065, with a minimum of $50, $75, $100 or $150 depending on the project. Sheds, water heaters, furnaces and air conditioners fall in the $50 tier. Room additions, detached garages and sunrooms fall in the $150 tier.

Item	Listed fee
Basement finish	$31.63 per sq ft rate, $100 minimum
Deck	$20.76 per sq ft rate, $75 minimum
Covered deck	$31.49 per sq ft rate, $100 minimum
Fence	$25
Demolition	$100
Rental occupancy, single-family / multifamily	$75 / $50
Water service	$75
Water or sewer tap, 1-inch meter or smaller	$2,500 each

Inspections

Schedule inspections in CitizenServe. Inspections booked through the portal usually happen the next day. Rental occupancy inspections can need two days’ notice, depending on when the request comes in.

Fire protection districts

O’Fallon is served by six independent fire districts: Central County Fire & Rescue, Cottleville, Lake Saint Louis, New Melle, O’Fallon and Wentzville. Each is a separate government outside the city’s authority, and a district may require its own building permit. Use the city’s emergency services map to find the district for your address, then check with that district as well as the Building Division.

Building staff

The Building Division posts direct lines for its staff. For residential questions, call the residential building supervisor at (636) 379-5564. For commercial questions, call the building official at (636) 379-5597. The city’s ICC code library, linked from the building page, has the adopted codes with O’Fallon’s ordinance changes and is free to read online.