How much does a building permit cost in unincorporated Platte County, MO?

The minimum permit fee is $25 retaining wall permit; $25 residential demolition permit; $50 electrical, mechanical, or solar permit; $75 pool or sign permit. Fees are calculated as: Mixed. Examples published by the county include deck permit $25 plus $0.10 per square foot over 300 square feet, swimming pool permit $75, fire rebuild permit $100 for first 500 square feet plus $0.05 per additional square foot, and commercial building permit $500 for first $5,000 estimated cost plus $25 for each additional $5,000. Plan check fee: Commercial permits also require payment of the county consulting engineering firm review cost before rough-in inspection.

What work is exempt from building permits in unincorporated Platte County, MO?

The following work is generally exempt: Mechanical like-for-like change-outs are stated as exempt when not changing from gas to electric or electric to gas; Retaining walls 4 feet high or less, measured from bottom of footing to top of wall, are exempt only when they do not support surcharge and do not have sloped backfill; No broader countywide exempt-work list was posted on the public permit page.

How do I schedule a building inspection in unincorporated Platte County, MO?

Inspections can be scheduled via: Online portal account, email to inspection@co.platte.mo.us, or phone at (816) 858-3338.

County Building Permits

Platte County, MO - 2026 Building Permit Guide

How to apply for a building permit in unincorporated Platte County, Missouri. Permit authority, application steps, fees, and inspection requirements.

Missouri Updated March 2026

Permit Authority

County permitting applies in unincorporated Platte County. Incorporated municipalities generally handle their own permits unless they expressly say otherwise

Department: Platte County Planning and Zoning
Address: Platte County Administration Building, 415 Third St., Room 016, Platte City, MO 64079
Phone: (816) 858-3338
Email: inspection@co.platte.mo.us
Website: https://www.co.platte.mo.us/planning-and-zoning

Online Permit Portal

Open https://www.co.platte.mo.us/

Platform: GovBuilt county website profile/applications portal • Account required: Yes • Submission: In-person only

Additional resources:

//www.co.platte.mo.us/ActivitySearchTool?Filter=Address&SearchText=&ContentType=case&Type=Building%20Permit%2C%20Final%20Plat%2C%20Fireworks%20Application%2C%20Flood%20Development%2C%20Land%20Disturbance%20Permit%2C%20Major%20Subdivision%20Preliminary%20Plat%20Application%2C%20Minor%20Subdivision%20Application%2C%20Planned%20Residential%20District%20Plan%2C%20Planned%20Unit%20Development%2C%20Platte%20County%20Parks%20and%20Recreation%20Project%2C%20ReZoning%20Application%2C%20Site%20Development%20Plan%20Application%2C%20Special%20Use%20Permit%20Application%2C%20Variance%20Application&SubType=&IsHideClosedStatus=true&IsSearch=true&Days=180

Application Process

Create or log into a profile on the county website
Open My Profile, then Applications, and select the appropriate permit type
Upload required plans, documents, and project details
County staff reviews zoning, building code, and companion reviews such as floodplain or land disturbance when triggered
Pay fees and obtain permit issuance
Keep approved documents available for inspections

Typical processing time: Not published as a fixed turnaround; inspections require 24 hours advance notice

Source: Platte County Planning and Zoning

General Requirements

County pages state permits are processed for new construction, accessory structures, renovations, additions, decks, pools, solar panels, electrical and mechanical change-outs, demolitions, retaining walls, signs, and commercial projects in unincorporated areas

Required Documents

When a permit is required: County pages state permits are processed for new construction, accessory structures, renovations, additions, decks, pools, solar panels, electrical and mechanical change-outs, demolitions, retaining walls, signs, and commercial projects in unincorporated areas
Required documents: Common requirements include owner and contractor information, site plan with setbacks and easements, plans or drawings, valuation, and a signed notarized affidavit. Commercial work may need utility, sewer, fire, and access approvals
Permit validity/expiration: Not clearly published on the main county permit page
Owner-builder rules if available: Applications may be submitted by owner, lessee, architect, engineer, builder, or agent; property owner name must match the recorded deed on many permit types
Contractor license requirements: Public page requires contractor information on applications; no countywide contractor licensing page was located
Building code adopted: The county permit page references the 2018 International Building Code and 2018 International Residential Code

Permit validity: Not clearly published on the main county permit page
Building code: The county permit page references the 2018 International Building Code and 2018 International Residential Code
Owner-builder: Applications may be submitted by owner, lessee, architect, engineer, builder, or agent; property owner name must match the recorded deed on many permit types
Contractor requirements: Public page requires contractor information on applications; no countywide contractor licensing page was located

Fees

Minimum permit fee: $25 retaining wall permit; $25 residential demolition permit; $50 electrical, mechanical, or solar permit; $75 pool or sign permit
Plan check fee: Commercial permits also require payment of the county consulting engineering firm review cost before rough-in inspection
Permit fee formula: Mixed. Examples published by the county include deck permit $25 plus $0.10 per square foot over 300 square feet, swimming pool permit $75, fire rebuild permit $100 for first 500 square feet plus $0.05 per additional square foot, and commercial building permit $500 for first $5,000 estimated cost plus $25 for each additional $5,000
Reinspection fee: Not separately published on the main public permit page
Payment note: Fee collection occurs after application review and before issuance; some permit types also require refundable bonds or notarized affidavit filings by final inspection

Fees change. Verify current amounts at the official fee schedule.

Work That Does NOT Require a Permit

Contact the Platte County Planning and Zoning to confirm whether your project requires a permit before starting work.

Inspections

How to Schedule

Online portal account, email to inspection@co.platte.mo.us, or phone at (816) 858-3338 ()

Inspection hours: Monday through Friday 8:00 am to 5:00 pm; inspection requests due 24 hours in advance; AM route 9:00 am to 12:00 pm and PM route 2:00 pm to 4:30 pm

Typical inspection sequence: Footing or pier, suspended slab engineer report if applicable, bonding for pools, prebackfill, ground rough, all trades rough-in, gas, final

Additional Resources

Building code: The county permit page references the 2018 International Building Code and 2018 International Residential Code
Zoning information: View zoning info
co.platte.mo.us
co.platte.mo.us
License lookup guide: Missouri Contractor License Requirements
Contract template: Missouri Homeowner-Contractor Agreement
Missouri hub: Missouri Contractor License & Permit Hub

Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Platte County Planning and Zoning before applying.

Frequently Asked Questions

Platte County Building Permit FAQ

Do I need a building permit in unincorporated Platte County, MO?: County pages state permits are processed for new construction, accessory structures, renovations, additions, decks, pools, solar panels, electrical and mechanical change-outs, demolitions, retaining walls, signs, and commercial projects in unincorporated areas
How much does a building permit cost in unincorporated Platte County, MO?: The minimum permit fee is $25 retaining wall permit; $25 residential demolition permit; $50 electrical, mechanical, or solar permit; $75 pool or sign permit. Fees are calculated as: Mixed. Examples published by the county include deck permit $25 plus $0.10 per square foot over 300 square feet, swimming pool permit $75, fire rebuild permit $100 for first 500 square feet plus $0.05 per additional square foot, and commercial building permit $500 for first $5,000 estimated cost plus $25 for each additional $5,000. Plan check fee: Commercial permits also require payment of the county consulting engineering firm review cost before rough-in inspection.
How do I apply for a building permit in unincorporated Platte County, MO?: 1. Create or log into a profile on the county website 2. Open My Profile, then Applications, and select the appropriate permit type 3. Upload required plans, documents, and project details 4. County staff reviews zoning, building code, and companion reviews such as floodplain or land disturbance when triggered 5. Pay fees and obtain permit issuance 6. Keep approved documents available for inspections
How long does it take to get a building permit in unincorporated Platte County, MO?: Typical processing time is Not published as a fixed turnaround; inspections require 24 hours advance notice.
What work is exempt from building permits in unincorporated Platte County, MO?: The following work is generally exempt: Mechanical like-for-like change-outs are stated as exempt when not changing from gas to electric or electric to gas; Retaining walls 4 feet high or less, measured from bottom of footing to top of wall, are exempt only when they do not support surcharge and do not have sloped backfill; No broader countywide exempt-work list was posted on the public permit page.
How do I schedule a building inspection in unincorporated Platte County, MO?: Inspections can be scheduled via: Online portal account, email to inspection@co.platte.mo.us, or phone at (816) 858-3338.

Need help with your project?

Navigating permits in Unincorporated Platte County can be complicated.

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Important: This page is an educational resource provided by jaspector.com. It is not legal advice, and it does not substitute for official guidance from the permit authority listed above. Permit requirements, fees, and processes change frequently. Always verify current requirements directly with the issuing department before beginning any construction project. Use of this page does not create an attorney-client relationship. Jaspector assumes no liability for any outcomes arising from reliance on this information.

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