Do I need a permit for a full kitchen remodel in
O'Fallon, Missouri?

O'Fallon full kitchen remodel permits — the key details

O'Fallon's Building Department requires a single unified permit application for kitchen remodels, but the permit itself spawns three separate sub-permits: building, plumbing, and electrical. You submit one Plan Set (floor plan + sections + electrical + plumbing + load-bearing wall calcs if applicable) to the O'Fallon permit portal or in person at City Hall. The building permit covers structural changes (wall moves, window openings, range-hood framing), plumbing covers sink relocation and drain routing, and electrical covers all new circuits and receptacle placement. Fees are calculated separately: building typically runs $300–$800 (based on 1.5–2% of project valuation); plumbing $200–$500; electrical $200–$600. Total permit cost is usually $700–$1,500 for a mid-range kitchen ($25,000–$50,000 remodel). O'Fallon's plan-review cycle is 3–6 weeks, not expedited; expect to be on-site with the plan examiner for at least one round of corrections (almost always on electrical: missing second small-appliance circuit, counter-receptacle spacing, or GFCI legend).

Load-bearing walls are the single biggest gotcha in O'Fallon kitchen remodels. IRC R602.3 defines a load-bearing wall as any wall supporting floor joists, roof loads, or the wall above; in a typical O'Fallon 1970s–1990s ranch or split-level home, any wall running perpendicular to joists (north–south in a west-facing kitchen, for example) is likely bearing. If you're removing one, the city requires a signed and sealed letter from a Missouri-licensed structural engineer stating the proposed beam size, support points, and bearing details. The engineer's letter must be stamped and included in your Plan Set before submission. A 12-foot kitchen opening with a 2x12 LVL or built-up beam might cost $400–$800 in engineering fees alone. The city will NOT approve a load-bearing wall removal on the basis of 'contractor says it's OK'—it's a red-flag reject on first review if the engineer's letter is missing.

Electrical code in O'Fallon kitchens is hyper-specific and the number-one reason for permit corrections. IRC E3702 requires a minimum of TWO 20-amp small-appliance branch circuits (SABC) dedicated to kitchen countertop receptacles; many homeowners and contractors forget the second circuit or fail to show it clearly on the submitted electrical plan. Every receptacle on the countertop must be GFCI-protected (IRC E3801) and spaced no more than 48 inches apart (measured horizontally along the countertop edge). The city plan examiner will count your receptacles on the submitted drawing and mark any that exceed the spacing. Island or peninsula countertops need receptacles too—a common miss. The refrigerator circuit is separate (dedicated 20-amp circuit), as is the range/cooktop (typically 40–50 amp, 240V, depending on appliance wattage). Dishwasher and disposal each typically get their own 20-amp circuit, though some disposals share the sink circuit if the combined load permits. Underestimate this, and you'll receive a plan correction notice in week 2 of review.

Plumbing relocation in O'Fallon kitchens must show trap-arm and venting routing on the submitted plan. If you're moving the sink location more than 3–4 feet horizontally or vertically (e.g., island install or relocation to a different wall), the drain line must be rerouted and the vent stack (or wet vent, if permitted by IRC P2722) must be shown. O'Fallon sits in Loess-soil terrain with alluvium in some zones south of I-44; the city's sewage infrastructure is robust in most residential areas, but the plan examiner will verify that your proposed drain slope (1/4 inch per foot minimum) is achievable in your basement or crawlspace. If you're installing a new rough-in and your home has a septic system (rare in O'Fallon proper, but possible in unincorporated zones), you'll need a septic design from a licensed Missouri septic designer—the city may defer to county authority depending on location. Gas-line modifications (if you're adding a gas range or moving one) require a separate plumbing permit sub-section and must show the new line routing, shut-off valve location, and appliance connection detail; IRC G2406 covers gas appliance connections, and the city inspector will verify the line is properly sized and pressure-tested.

Range-hood duct termination is a code detail O'Fallon examiners always flag if missing. If you're installing a range hood with exterior ducting (not recirculating), the Plan Set must show a wall section or detail drawing of the exterior termination cap—specifically, the duct diameter, cap type (typically a 6-inch or 8-inch wall or roof cap with damper), and the soffit clearance if applicable. Many homeowners assume 'install a range hood' is cosmetic and exempt; it's NOT if it requires cutting a wall, running ductwork, and terminating outside. The city treats this as a building/mechanical permit item. If you're installing a recirculating (charcoal-filter) hood, no exterior duct is needed, but you must clearly label it 'recirculating' on the plan to avoid an examiner ping-back.

Three O'Fallon kitchen remodel (full) scenarios

O'Fallon's two-small-appliance-circuit rule and why plan examiners obsess over it

IRC E3702 requires two 20-amp small-appliance branch circuits (SABCs) in every kitchen, and O'Fallon's plan examiners treat this as a first-pass check. The two circuits must serve all countertop receptacles, the sink area, and the refrigerator (though some codes allow the fridge on a dedicated third circuit). Many homeowners and DIY-savvy contractors miss this because they're accustomed to older kitchens with one or two small outlets; modern code demands redundancy and capacity for simultaneous small-appliance use (toaster and microwave running at once, for example). Each SABC must be protected by a 20-amp breaker, wired with 12-gauge copper or 10-gauge aluminum (not 14-gauge), and show clearly on the electrical plan as separate circuits with distinct colors or line styles.

When you submit your Plan Set to O'Fallon, the electrical inspector's first annotation will be a red circle around any missing second SABC. If your plan shows only one, you'll receive a plan correction notice in week 2–3 of review, forcing you to revise the electrical drawing, resubmit, and restart the review clock. This adds 2–4 weeks to your timeline. To avoid it, ensure your electrical contractor explicitly labels two separate SABC lines on the submitted drawing, each terminating at its own breaker in the panel. Island or peninsula countertops must be served by these SABCs too; if your island is 3 feet from the main counter, you still need receptacles there spaced no more than 48 inches apart, and they draw from the SABC pool.

The logic behind the two-circuit rule is simple: if one circuit trips (overload), you still have power on the other. But many kitchen designs cram both circuits into a single wall run, making the electrician's job trickier; he must either run two separate cables or use multi-conductor cable and carefully identify which conductors belong to which circuit at both ends. This adds labor cost ($300–$600 depending on cable routing and wall finish), and some contractors don't budget for it upfront, leading to mid-project surprises. Plan for it in your bid; it's non-negotiable in O'Fallon.

Load-bearing wall removal: the structural-engineer letter requirement and what it costs

If your full kitchen remodel includes removing any wall (even a partial height wall if it's carrying floor or roof loads), O'Fallon requires a signed and sealed letter from a Missouri-licensed Professional Engineer (PE) specializing in structural design. The letter must specify the existing load (typically calculated as dead load from drywall, framing, and contents plus live load from occupancy), the proposed beam size and material (e.g., built-up 2x12 with 1/2-inch plywood web, or LVL 2.0E 2x12), bearing details at each end (e.g., bearing on 6x6 posts on concrete footings), and a stamp + signature by the PE. O'Fallon's plan examiner will cross-reference this letter against the architectural plan to ensure the beam location, span, and support align with the drawing.

The engineer's fee typically runs $400–$800 for a simple kitchen wall removal with one or two bearing points. The engineer will visit your home, measure the wall location and existing framing, determine the load (often 20–40 psf for a residential interior wall plus contents), size the beam using design tables or calc software, and issue the letter. Many structural engineers require a half-day site visit ($300–$500) plus engineering time ($150–$300), and some add a re-visit fee ($150–$250) if the contractor changes the design during construction. Do NOT skip this step or hire a contractor to 'eyeball' it; O'Fallon will reject the permit application without a PE-signed letter, and building unpermitted load-bearing removal risks catastrophic framing failure (floor sag, cracking, or collapse).

One common mistake: homeowners hire an engineer, get the letter, but the contractor installs a beam that's smaller than specified (e.g., single 2x12 instead of the engineered 2x12+plywood sandwich) to save cost. The final inspection will likely catch this; the inspector may demand the beam be opened for inspection and may reject the work if it doesn't match the engineer's letter. Expect to pay the contractor extra to remove and replace the beam if this happens. Always ensure the submitted engineer's letter is forwarded to your contractor and the sub doing the framing, and confirm the beam will be built exactly as specified.

Common questions