Clayton, Missouri Building Permit Guide

Permits for work inside Clayton come from the City’s own Building Services division, part of the Planning and Development Services Department at 10 N. Bemiston. Every application is filed and paid in the Citizenserve portal; a building permit costs $125 for work up to $18,000 and $7.80 per $1,000 for projects over $18,000 (up to $8 million), plus a $35 processing fee, and inspections requested before 4 p.m. can be made the next day.

What needs a permit in Clayton?

An owner or agent must get a City permit before building, enlarging, altering, repairing, moving or demolishing a building, changing its occupancy, or installing or altering electrical, gas, mechanical or plumbing systems.

Exterior changes that affect appearance (color or style, fences, driveways, walkways, retaining walls, window replacement, hardscape) need approval from the Architectural Review Board or an administrative architectural review, and front-yard retaining walls always go to the Board. The City asks owners to contact the Planning Division before choosing a contractor for exterior work.

Clayton building department: who handles permitting

The Building Services division reviews plans, issues permits, inspects construction and administers the property maintenance code. Thomas Lard, RA, is the Building Official. The Planning and Zoning Division handles zoning, plats and Architectural Review Board items, Public Works handles right-of-way, after-hours work and stormwater permits, and the Clayton Fire Department reviews fire protection work.

Filing in Citizenserve

Clayton accepts permit applications only through its Citizenserve portal. Drawings are uploaded as PDF files during the application, each no larger than 25 MB; hand drawings must be scanned to PDF first. Staff check that every required field and document is present, then send a notice of the initial application fee. The review clock starts when that fee is paid in the portal.

The City’s Applications, Forms & Permits page posts the fee schedule, a plan review timeline, an application signature form, an amendment/addendum form and submission checklists for fences, demolitions, residential solar, residential occupancy permits, Architectural Review Board items, construction parking plans and stormwater facilities. Fire safety construction and operational permits, land disturbance permits and right-of-way permits are also filed in Citizenserve.

Interior demolition is not permitted on its own in the portal: it must be part of a new tenant fit-out or a White-Box permit for a fully finished space. Fence work is applied for under the building permit.

Projects worth $2,500,000 or more must follow an approved Construction Parking Management Plan, filed with the building or demolition permit; the Building Official can also require one for smaller projects where street parking is tight.

Clayton permit fees

Fees come from the Planning and Development Services Permit and Application Fee Schedule adopted by the Mayor and Board of Aldermen on February 11, 2025 and in effect since May 1, 2025; the Citizenserve portal still links this schedule. Every permit carries a non-refundable $35 processing fee on top of the review fee, and Clayton issues no combined permits: building, plumbing, mechanical, sign, dumpster and demolition work each need their own.

For example, a $50,000 kitchen remodel pays $390 in building review fees (50 × $7.80) plus the $35 processing fee, a total of $425, before separate plumbing, mechanical and County electrical permits. The valuation must include materials and industry-standard labor, and the City can ask for a detailed cost breakdown. Starting work before the permit is issued adds 100% of the usual total permit fee, and a Stormwater Pollution Prevention Plan review costs $300.

Plumbing, mechanical, electrical and fire work in Clayton

Plumbing: permitted by the City under the 2021 International Plumbing Code. Only a licensed master plumber holding both a St. Louis County licence and a City of Clayton licence ($45 a year) may obtain the permit and do the work.

Mechanical and fuel gas: new or replacement heating, cooling and ventilation equipment and generators need a City permit under the 2021 International Mechanical and Fuel Gas Codes. Outdoor condensing units, pool pumps and similar equipment must sit at least five feet from side and rear property lines and be screened as approved.

Electrical: Clayton applies the 2014 National Electrical Code as part of the St. Louis County amendments, but all electrical permits are obtained from and inspected by St. Louis County. The electrician requests inspections from the St. Louis County Electrical Department (314-615-5000), and the electrical inspection must be approved before the City’s framing inspection.

Fire: Clayton enforces the 2021 International Fire Code with local amendments. The Clayton Fire Department asks for two sets of drawings signed and sealed by the design professional with each fire plan review, and issues fire safety construction and operational permits through Citizenserve.

How to get a Clayton building permit

Clayton inspections and job-site rules

The permit card lists the inspections the project needs, and a project stays open until the final inspection. Request an inspection from the project file in Citizenserve or by emailing inspectionsbd@claytonmo.gov with the inspection type, permit number, address, a contact name and phone number, and the date and morning or afternoon slot wanted. Requests received before 4 p.m. are eligible for the next day; later requests go on the schedule for the following business day.

Construction is allowed from 7 a.m. to 6 p.m. Monday to Friday. Evening, weekend and holiday work needs an Emergency/Evening/Weekend Work Permit from Public Works. Buildings under construction or demolition, and excavations deeper than 5 feet, must be enclosed by a solid wood construction fence at least 6 feet high, approved by the Building Official and put up no more than 10 days before work starts. Dumpsters not behind a construction fence need a dumpster permit and must be covered, and trees near the work must be protected.

Occupancy permits, stormwater and floodplain rules in Clayton

Commercial occupancy: every business needs a Commercial Occupancy Permit, with inspections by both the Planning and Fire Departments, before it occupies commercial space. This applies to each change of tenant even if no construction was done between tenants.

Rental homes: a Residential Occupancy Permit is required for every rental property, renewed at each change of tenant or every five years if the tenant stays. The application fee, covering the first inspection and one re-inspection, is $80 for a single-family house and $60 per duplex or apartment unit, plus the $35 processing fee; the fee doubles if the home is occupied before the inspection, and five-year inspections of apartment buildings cost $100 plus $35 per unit.

Stormwater: demolition and new construction disturbing 5,000 sq ft or more need a Stormwater Pollution Prevention Plan approved by Public Works before the building or demolition permit is released; disturbance of one acre or more also needs a Land Disturbance Permit.

Right-of-way: excavation in the street or tree lawn, curb cuts, driveway approaches and public sidewalks need a Right-of-Way Permit from Public Works, and sidewalks damaged during construction must be replaced to City standards.

Floodplain: the Building Official is Clayton’s floodplain administrator. Development in the A and AE zones on the County flood maps dated February 4, 2015 needs a floodplain development permit, and new or substantially improved homes must have the lowest floor at least one foot above the 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

Clayton permit FAQ

Who issues building permits in Clayton, Missouri?

The City of Clayton’s Building Services division in the Planning and Development Services Department, not St. Louis County. St. Louis County handles only the electrical permits and inspections.

How much is a building permit in Clayton?

$125 for work costing up to $18,000, and $7.80 per $1,000 of construction cost for projects over $18,000 (up to $8 million), plus a $35 processing fee. A $50,000 project pays $425.

Can I submit paper plans in Clayton?

No. Applications, drawings and payments all go through the Citizenserve portal; hand drawings must be scanned to PDF.

Which building codes apply in Clayton?

The 2021 International Building, Residential, Mechanical, Plumbing, Fuel Gas, Energy Conservation, Existing Building and Swimming Pool and Spa Codes, effective January 1, 2023, plus the 2014 National Electrical Code.

Do I need a permit to replace my furnace or air conditioner?

Yes. New or replacement heating, cooling and ventilation equipment needs a City permit.

Who can pull a plumbing permit in Clayton?

A master plumber licensed by both St. Louis County and the City of Clayton.

Do I need an occupancy permit to rent out a home in Clayton?

Yes. Rental homes need a Residential Occupancy Permit at each change of tenant, or every five years if the tenant does not change.

Can contractors work on Saturdays?

Not without an Emergency/Evening/Weekend Work Permit from Public Works; normal hours are 7 a.m. to 6 p.m. on weekdays.

Clayton permit search and official resources

• Clayton Building Services
• Clayton applications, forms, fee schedule and checklists
• Clayton Citizenserve permit portal
• Clayton Planning and Development fee schedule (effective May 1, 2025)
• Clayton Planning and Development Services staff
• St. Louis County municipality contract list (codes the County enforces in each city)
• Clayton frequently asked questions
• Clayton SolSmart solar program
• Clayton City Code Chapter 500, building codes and amendments
• Clayton City Code Chapter 420, floodplain management

Simplify Clayton 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 Clayton permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.