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Deck Construction · Franklin County, Missouri
In Missouri, there is no single statewide rule for a Deck Construction; whether you need a permit is decided locally in Franklin County.
There is no single statewide building code, so the rule is set by your local jurisdiction; most still require a permit for any deck attached to the house or more than 30 inches above grade. Because Missouri leaves this to local jurisdictions, the reliable answer comes from Building Permits & Inspections. Zoning setbacks apply either way.
Source: Local, IRC 2018 · Verified 2026 by StateDataIndex
Building a deck typically requires a permit if it is attached to the house, over 30 inches off the ground, or exceeds a certain square footage (often 200 sq ft).
With a population of around 105,950 residents, Franklin County generally runs a more streamlined permitting process than major urban hubs.
In high-wind, tornado-prone areas, inspectors strictly verify structural anchoring and framing compliance under the Missouri Building Code.
For Franklin County residents, we highly recommend reviewing your neighborhood HOA covenants before paying any municipal fees. Often, homeowners associations maintain stricter rules regarding materials and dimensions for your Deck Construction than the county itself.
Missouri exhibits a sharp divide between highly regulated urban zoning in St. Louis and Kansas City, and virtually unzoned rural counties in the Ozarks. Fortunately, Missouri maintains relatively builder-friendly regulations, keeping base permit fees competitive.
Permit fees vary by jurisdiction and by your project's valuation, so there is no single fixed figure for Franklin County. We only publish fees confirmed by real homeowners — none have been reported here yet.
Confirm the current fee directly with Building Permits & Inspections ((636) 583-6384). If you have paid for a permit here, you can add it here to help others.
Office: Building Permits & Inspections
Address: 400 E Locust St, Union, MO 63084, USA
Phone: (636) 583-6384
Source: official Franklin County government records. Hours and procedures can change — call ahead to confirm.
In Franklin County, you or your contractor typically submit blueprints and a property survey to the local building department. Call ahead to confirm hours and accepted payment methods.
When applying for a Deck Construction permit, you or your contractor will generally need to submit the following documentation for the city's review:
Key code points for a Deck Construction in Franklin County: Decks higher than 30 inches above grade legally require guardrails (typically 36 inches high), and stairs with 4 or more risers require a handrail.
Typical processing time for a jurisdiction of this size: 10 to 14 business days.
Building without authorization is considered a code violation. The local government can issue a Stop Work Order, forcing you to halt construction immediately. You may be subject to retroactive permit fees (often double the original cost), daily fines, or even a mandate to tear down the unpermitted work at your own expense.
Yes. Missouri generally allows property owners to act as their own general contractor under an Owner-Builder exemption. If you take this route, you assume full legal and financial liability and must ensure all work complies with the Missouri Building Code.
Permit fees vary by jurisdiction and by your project's valuation, so Franklin County does not publish a single fixed figure. Confirm the exact fee with the local building department before applying.
Based on the size of Franklin County, the typical processing time is 10 to 14 business days. Times vary with the season and the building department application volume.
You can apply through the Building Permits & Inspections or online via the county permit portal. For questions, call (636) 583-6384.
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