Cass County, MO Building Safety: Building Permits (2026)
Key Facts
- Code adopted
- 2006 International Building Code
- Enforcing agency
- Building Codes Department
- Small-shed exemption
- Accessory structures under 400 sq ft
- Application fee
- $50.00 (dwellings/commercial) or $25.00
- General penalty
- Up to $1,000.00, § 100.210
Summary
Unincorporated Cass County has adopted the 2006 International Building Code as its Building Code, and the Building Codes Department administers it as the Code Official. A building permit is required for construction, alteration, or repair work in the unincorporated county unless the project falls under the code's narrow exemption for small accessory structures.
A certain document, three (3) copies of which one (1) copy is on file in the office of the Cass County Clerk and the remaining two (2) copies may be maintained in the Building Codes office of the County of Cass, Missouri, being marked and designated as the International Building Code, 2006 Edition, including Appendix Chapters C, E and H, as published by the International Code Council, Inc., be and is hereby adopted as the Building Code of the County of Cass in the State of Missouri for the control of building and structures as herein provided ... IBC Section 105.2. Work exempt from permit. Delete item number 1 and insert the following. One-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed four hundred (400) square feet (37.1 m2). FPN: This exception from a building permit from the Building Codes Department does not preclude the requirement for a building permit to be obtained from the Cass County, Missouri Zoning Department or meeting the Cass County, Missouri Zoning Ordinance rules and regulations.
Full Breakdown
010 adopts the 2006 IBC, including Appendix Chapters C, E and H, "for the control of building and structures" in unincorporated Cass County, and renames the code's enforcement office the Building Codes Department. 2 to replace the standard permit exemption: only one-story detached accessory structures used as tool sheds, storage sheds, playhouses, and similar uses under 400 square feet are exempt from a Building Codes Department permit. Even then, the code's own footnote warns the exemption "does not preclude the requirement for a building permit to be obtained from the Cass County, Missouri Zoning Department," so a shed owner may still need zoning sign-off.
Everything larger, including new houses, additions, garages, decks, and finished basements, needs a Building Codes Department permit before work starts. 00 for other permit types; the application fee is not credited against the final permit fee. 020, covering habitable space, decks, basements, garages, manufactured home installation, and swimming pools. The county also separately adopted the 2006 International Residential Code, Post Frame Building Standards, and the Mechanical, Electrical, Plumbing, and Fuel Gas codes, each carrying its own permit trigger under the same Chapter 500 framework.
Violations & Fines
Cass County Code Section 100.210's General Penalty applies where Chapter 500 sets no specific fine: building without the required permit is punishable "by a civil penalty not exceeding one thousand dollars ($1,000.00)," and "every day any violation of this Code shall continue shall constitute a separate offense," so an unpermitted project can accumulate daily exposure until it is brought into compliance with the Building Codes Department.
Frequently Asked Questions
Do I need a permit to build a shed in unincorporated Cass County?
Which office issues building permits in unincorporated Cass County?
How much is the application fee for a Cass County building permit?
Sources & Official References
Other rules in Cass County
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