Cass County, Missouri Building Permit Guide

On unincorporated land, Cass County’s Building Codes, Zoning & Environmental Health department, 30508 S.W. Outer Road, Harrisonville (816-380-8134), issues building permits, zoning approvals and septic permits and inspects the work. Plans are reviewed under the 2006 International Codes, applications must be handed in at the office by the permit holder, and a new home is charged $1.47 per square foot of living space; for a home on a septic system, $350 is due with the application, covering the $300 septic permit. Cities such as Belton, Raymore, Harrisonville and Peculiar run their own permit offices.

Cass County building department: who handles permitting

The county department, open Monday to Friday from 6:30 a.m. to 3 p.m., covers building codes, zoning and environmental health for the unincorporated county, and it is also the county’s floodplain administrator and its onsite wastewater authority under a county ordinance. Building permits are not issued at the time of application, so allow for plan review. The department has warned of scam emails that claim money is owed for a building permit or zoning action.

Most of the county’s people live in cities that issue their own permits. Populations are Census Bureau Vintage 2025 estimates for the part of each city inside Cass County.

How to apply to the county

Each permit type has its own application packet, and the county will not take applications by mail, email or fax: the permit holder brings the completed packet to the Harrisonville office and takes responsibility for the project from start to finish. For a new house, modular home or room addition the packet asks for:

• A completed questionnaire naming the fire district, water district and gas and electric utilities, with proof of a connection to a public water system.
• The full legal description and a site plan showing easements, existing buildings and setbacks.
• One set of plans, on sheets at least 24 by 36 inches, with floor plans, framing details and a foundation plan showing 36-inch frost depth.
• Plans sealed by a Missouri engineer for vaulted roofs, studs over 10 ft, cantilevers of 2 ft or more, foundation walls holding back 9 ft or more of fill, truss and I-joist layouts and post-frame homes.
• A septic application with a soil evaluation by a licensed soil scientist.
• A letter from the county GIS coordinator assigning the new address (816-380-8190).

Commercial projects need two original plan sets, and every residential solar system must be fully designed, with original plans sealed and signed by a Missouri engineer or architect.

Cass County permit fees

The fee tables are printed in the county’s application packets, updated September 26, 2025 (July 27, 2026 for commercial applications).

Slab-on-grade and earth-contact homes pay 25% less than the table total. For example, a 2,000 sq ft house on a crawl space with a 500 sq ft attached garage comes to $2,940 plus $170, or $3,110, in building permit fees, besides the $350 paid at application. The remodel table charges $201.25 for the first $2,000 of value plus $40.57 per $1,000 up to $25,000, falling to $16.22 per $1,000 between $100,000 and $500,000; the deck and pool deck packet prints lower rates for the $50,001–$500,000 bands, so ask which table applies to your job.

Inspections and occupancy

Request inspections by phone at 816-380-8134 between 6:30 a.m. and 3 p.m. with the permit number, address and inspection type. Most are done the next workday; footings, foundation walls, piers and post holes can be inspected the same day if called in by 1:30 p.m. and ready by 2 p.m. There are no appointment times; call the office that morning to ask about the inspector’s route. Inspectors cannot use lock boxes, key codes or alarm codes, so the building must be open.

If items on a correction list are still not fixed, every re-inspection after the first costs $100, and the county can also charge $100 when a structure is locked or the work is not ready. The final inspection is not booked until the septic system has its final approval, and no building may be occupied before a Certificate of Occupancy; extending a temporary certificate costs $338. A permit lapses if work does not start and an inspection is not requested within 180 days, and work must be finished and approved within one year.

Septic, zoning, roads and flood rules

Septic systems: under Onsite Wastewater Regulations Ordinance 26-03, approved February 4, 2026, every new, repaired or modified system on unincorporated land needs a county permit first. A permit for a new system or a full or partial replacement costs $300, a bathroom in an accessory building tied into the house system $75, and a re-inspection $100; installers who start without applying are charged $150 for failing to submit plans. Adding a bedroom or bathroom without changing the system needs a $75 septic exemption permit. The ordinance does not allow a lagoon (wastewater stabilization pond) for a single home on a lot under 3 acres unless the County Commission grants a variance signed off by a licensed engineer. The county’s September 2025 application packet still says evaporation ponds need at least 5 acres, but the February 2026 ordinance is the newer adopted rule.

Zoning: the county’s building and residential code amendments exempt one-story sheds, playhouses and similar buildings up to 400 sq ft from a building permit, but the code notes that this does not remove any permit required by the zoning department or the county’s zoning rules. Setbacks for any building come from the zoning office.

Driveways and road work: a culvert or entrance permit costs $100 (cash or check) through Road & Bridge. Boring under a county road costs $500 and an open cut on a gravel road $1,000, with a bond of $1,000 for each bore job, or $5,000, $20,000 or $30,000 per mile for gravel, chip-and-seal or asphalt roads.

Flood rules: Cass County takes part in the National Flood Insurance Program, with flood maps dated January 2, 2013. Rebuilding or repairing a flood-damaged building in a special flood hazard area needs a building permit, and septic applications are checked against the flood map. Loch Lloyd and West Line are listed by FEMA as not participating.

Livestock operations: on September 2, 2026 the County Commission approved Ordinance 26-08, amending section 410.040 of the county code on water pollution hazards and setbacks for concentrated animal feeding operations.

How to get a county building permit

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

Cass County permit FAQs

Who issues building permits in unincorporated Cass County?

Building Codes, Zoning & Environmental Health, 30508 S.W. Outer Road, Harrisonville (816-380-8134). Cities such as Belton, Raymore, Harrisonville and Peculiar issue their own.

How much is a county building permit for a new house?

$1.47 per square foot of living space, $0.34 per square foot of attached garage, plus $350 at application ($300 septic permit and $50 application). A 2,000 sq ft house with a 500 sq ft garage pays $3,110 in building fees.

Can I apply online or by mail?

No. The county accepts applications only in person at its Harrisonville office, from the permit holder.

Which building code does Cass County use?

The 2006 International Codes with county amendments, adopted by Ordinance 08-06 in December 2008, and the 2005 National Electrical Code.

Do I need a permit for a shed?

One-story sheds and playhouses up to 400 sq ft need no county building permit, though the zoning department may still require its own permit; larger accessory buildings pay $0.25 per square foot.

How much is a septic permit?

$300 for a new, replacement or modified system on unincorporated land, under Ordinance 26-03 of February 2026.

How fast are inspections?

Most are done the next workday; footings and foundations can be inspected the same day if called in by 1:30 p.m.

Cass County permit search and official resources

• Cass County Building Codes, Zoning & Environmental Health
• Cass County new home, modular home and room addition packet
• Cass County remodel and repair packet
• Cass County residential accessory building packet
• Cass County inspection request procedure (November 2025)
• Cass County Onsite Wastewater Ordinance 26-03
• Cass County culvert permit
• Cass County right-of-way work permit
• Cass County 911 addressing FAQs
• Cass County Code of Ordinances
• FEMA Community Status Book: Missouri
• City of Peculiar Building Permits Division
• City of Archie building permits and inspections
• Village of Loch Lloyd building permits and inspections

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