Wentzville, Missouri Building Permit Guide

Inside Wentzville, building permits come from the City’s Building Division, not St. Charles County, and all 2026 applications, plans, payments and inspection requests go through the SmartGov portal. The permit fee is 0.5% of the construction cost, using the higher of the stated cost or the International Code Council valuation, and miscellaneous permits are usually reviewed in five to seven business days.

What requires a building permit in Wentzville?

A permit is required to build, modify or, in some cases, repair a structure. Minor work such as changing a faucet does not need one. Besides new homes and commercial buildings, the City lists these miscellaneous permits:

Driveways need a permit, as do slabs near a curb cut at an intersection; patios and other slabs not tied to a driveway do not. Work already done without a permit can be permitted after the fact with a Miscellaneous Permit Application that says the work is complete.

Wentzville building department: who handles permitting

The Building Division of the Community Development Department provides plan review, inspections, permit issuance, code enforcement, occupancy inspections and an annual property maintenance program. Jessica Isaak is the Building Official.

Contractor licence: every general contractor and subcontractor needs a City-issued contractor licence before working in Wentzville, renewed every year by February 28. Questions go to the City Clerk’s office at 636-327-5101.

Wentzville permits and the SmartGov portal

Wentzville has moved to an all-digital application and plan review system and no longer accepts paper plans for building, planning or zoning submittals. Register in the SmartGov customer portal to apply for building, engineering (lot deposit and right-of-way) and planning permits, upload plans, pay fees, request inspections and look up applications and issued permits. Floodplain, sign and other planning applications are moving to the same portal.

Permits applied for in 2025 or earlier stay on the old system: questions about an unissued older permit go to permits@wentzvillemo.gov. Certificates of occupancy issued from 2026 can be downloaded in SmartGov; older ones are requested on the City’s certificate of occupancy form.

Review times from the Building Division: about 5–7 business days for miscellaneous permits, 7–10 business days for a new “master” house plan and 5–7 business days for a repeat (“same as”) house.

Wentzville permit fees

Fees come from Section 500.350 of the City Code (Ordinance 2022-4336), shown on the City’s Building Fees page dated January 1, 2023. ECC is the estimated cost of construction on the application; for new buildings the City also calculates a cost from the International Code Council’s Building Valuation Data and uses whichever is greater.

The City’s own example: an application stating $100,000 for a building the valuation data puts at $124,359 pays $124,359 × 0.0050 = $621.79 for the permit. A $30,000 finished basement pays $150 plus the $50 plan review fee.

Connection and supply fees for new water and sewer service, water and sewer line fees, the water deposit and backflow fees are added to a new building permit; the Engineering Division gives estimates. Engineering also charges for site work: plan review and grading permits at $150 plus $10 per lot (or per acre for other development), construction permits at 2% of the estimated cost of public improvements less the plan review fee, and right-of-way permits at $100 plus $0.50 per linear foot of excavation.

Electrical, plumbing and mechanical permits in Wentzville

New electrical, plumbing and HVAC work, and sewer and water installations or repairs, are miscellaneous permits from the Building Division at 0.5% of the estimated cost (minimum $35 for residential work) plus plan review. The City enforces the 2020 National Electrical Code and the 2021 plumbing, mechanical and fuel gas codes; in January 2026 Ordinance 4628 removed the 2021 residential code’s emergency disconnect requirement (Section E3601.8). Every trade contractor needs the City contractor licence.

Homeowners may do work of a minor nature themselves, but the City can require a licensed professional if an inspection finds excessive violations.

Alliance handles electrical permit filing for contractors here. More on this: who pulls the electrical permit.

Plans and design data

Everything is uploaded to SmartGov in digital form. Plans examiners may call with questions, and accurate, clearly described paperwork is the City’s stated route to a permit within a few days. Engineering reviews plot plans for new homes before construction, and builders of new homes submit a soils report, spot survey and drywall screw inspection report to the City during construction.

How to apply for a Wentzville permit

Wentzville inspections

Request inspections for 2026 permits in SmartGov. For permits issued in 2025 or earlier, the City’s older online request form applies: inspections are offered Monday to Friday from 8 a.m. to 3 p.m. with a break for lunch, requests must be in by 3 p.m. the day before for next-day service, and 24–48 hours’ notice is advised. Footings, sewer laterals and occupancy inspections get timed appointments; others are booked for a morning or afternoon. The third and later re-inspections cost $50 each.

A permit becomes expired if no inspection is done in the first 180 days or within 180 days of the last one; extensions are requested on the City’s Request to Extend a Permit form.

Local Wentzville rules

Basements on new homes: since Ordinance 4647 (May 13, 2026), each new single-family house in the R-1A to R-1E districts must have a basement. The Building Official can approve exceptions in writing, for example for split-level designs, a high water table, bedrock or unsuitable soil, steep sites, regulated flood hazard areas, or universal design, zero-entry and 55-plus homes.

Occupancy inspections: the City does not inspect houses on sale, but every change of resident at a rental requires a $50 occupancy inspection, valid for 90 days, before the new occupant moves in. Businesses need a commercial occupancy permit and business licence whenever a space changes occupant or owner.

Data center moratorium: Ordinance 4686, passed on October 7, 2026, bars permits and approvals for large-scale data centers (over 5 megawatts, over 100,000 sq ft, or a multi-building campus) for six months from taking effect on enactment and approval, to about April 7, 2027, unless the Board of Aldermen repeals or extends it.

Floodplain: Wentzville is in the National Flood Insurance Program on flood maps dated January 20, 2016. The Community Development Director is the floodplain administrator, and new or substantially improved homes in the floodplain must have the lowest floor 1 foot above base flood elevation.

Missouri building code

Missouri has no mandatory statewide building code for private construction: a county, fire protection district or municipality may adopt one (usually by reference under RSMo 67.280), and in parts of the state none has. Building codes in Missouri

Wentzville building permit FAQ

Does St. Charles County issue building permits in Wentzville?

No. The City of Wentzville Building Division issues building permits inside city limits through its SmartGov portal.

How much is a building permit in Wentzville?

0.5% of the construction cost, using the greater of your stated cost or the ICC valuation for new buildings, plus plan review ($50 for a new house). Miscellaneous residential permits start at $35 plus $50 plan review.

Can I submit paper plans?

No. All building, planning and zoning submittals must be digital through SmartGov.

How long does a permit take?

About 5–7 business days for miscellaneous permits and 7–10 business days for a new master house plan.

Does a new house in Wentzville need a basement?

In the R-1A to R-1E districts, yes, since May 2026, unless the Building Official approves one of the listed exceptions.

Do I need an inspection to rent out a house?

Yes. Each new resident at a rental needs a $50 City occupancy inspection first; a sale alone does not.

Wentzville permit search and official resources

These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.

• Wentzville Building Division
• Wentzville building permits
• Wentzville Permit Center (SmartGov)
• Wentzville SmartGov customer portal
• Wentzville building fees
• Wentzville Code Section 500.350, permit fees (Ordinance 2022-4336)
• Wentzville adopted building codes
• Wentzville building inspections
• Wentzville occupancy requirements
• Wentzville Ordinance 4647, basements for new homes
• Wentzville Ordinance 4686, data center moratorium
• Wentzville Code Chapter 415, floodway and floodway fringe districts
• Wentzville engineering construction and development permits

Simplify Wentzville permitting with Alliance Permitting

Alliance Permitting is a permit documentation and submission company in Missouri. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Wentzville permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.