Do I need a permit in Union, Missouri?
Union, Missouri operates under Missouri's statewide building code framework, which adopts the International Building Code (IBC) with state amendments. The City of Union Building Department handles all residential and commercial permits within city limits. Most projects in Union require a permit before work begins — including decks, sheds, roofing replacements, electrical work, HVAC installations, and foundation repairs. The exception is owner-occupied residential work performed by the property owner on a single-family home, which has more flexibility under Missouri law, though certain trades (electrical, plumbing) typically still require licensed contractor involvement and permitting. Union's 30-inch frost depth is shallower than much of the Midwest, but deck footings, foundation work, and below-grade projects still need to respect that threshold. The soil composition — loess in the northern part of the city, karst features to the south, and alluvium in low-lying areas — can affect footing and drainage requirements, especially for basements and crawlspace work. The City of Union Building Department processes most residential permits over-the-counter and by mail. There is no universally accessible online filing portal as of this writing, so contact the building department directly to confirm current filing methods and portal availability.
What's specific to Union, Missouri permits
Union adopts the International Building Code (IBC) with Missouri amendments, not a modified edition unique to the city. This means most residential projects follow the same rules you'd encounter in other Missouri cities. However, Union's local zoning ordinance does set specific rules on setbacks, lot coverage, and use restrictions — these vary by zoning district (residential, commercial, industrial). Always verify your property's zoning designation before designing a project; a shed or deck that's legal in one zone may violate setback or height restrictions in another.
The 30-inch frost depth in Union is manageable for most residential footings, but it's not trivial. Deck posts, garden sheds, and fences all require footings that bottom out below 30 inches to prevent frost heave. This is especially important in Union's northern areas where loess soil is prevalent. If you're doing any below-grade work — basement repair, drainage tile, utility trenches — the building department may request soil-boring information or a geotechnical assessment, particularly in the karst-prone southern part of the city where sink-hole risk is elevated.
Owner-builders have significant latitude in Missouri for single-family residential work on owner-occupied property. You can pull your own residential permit and perform the work yourself without a contractor license, provided the work meets code. However, electrical and plumbing work almost always require a licensed electrician and plumber, even if you're the permit holder and you're doing other trades. A common mistake is assuming an owner-builder exemption covers all trades — it doesn't. Electrical subpermits and plumbing subpermits will be scrutinized by inspectors just as rigorously as contractor work.
Permit fees in Union are typically calculated as a percentage of project valuation. Most residential permits run $50–$250 depending on scope. A simple shed or fence permit might be a flat fee ($50–$75); a deck or room addition will be assessed at roughly 1.5–2% of the declared project value. Plan review is bundled into the base fee. If the project requires multiple subpermits (electrical, plumbing, HVAC), each may have its own fee — plan to add $25–$50 per trade. Inspections are included in the permit fee; there are no per-inspection charges.
The most common reason residential permits get rejected in Union is missing or incomplete property-line surveys and site plans. The building department needs to verify setbacks, especially for decks, additions, and fences. Bring a copy of your property deed or a recent survey. The second most common rejection is undersized footings or missing footing-depth documentation for projects in frost-prone areas. The third is lack of structural calculations for load-bearing walls, deck beams, or roof framing. Submitting clear, dimensioned drawings from the start saves weeks of back-and-forth.
Most common Union, Missouri permit projects
Union homeowners and builders most frequently need permits for decks, additions, roofing work, electrical upgrades, and foundation repairs. Below are the permit types you'll encounter most often:
Union, Missouri Building Department contact
City of Union Building Department
Union City Hall, Union, MO (contact city hall for specific building department address and office location)
Search 'Union MO building permit phone' or contact Union City Hall main line to be directed to Building Department
Typical city office hours: Monday–Friday, 8 AM–5 PM (verify locally before visiting)
Online permit portal →
Missouri context for Union permits
Missouri adopts the International Building Code (IBC) at the state level, with amendments that favor owner-builder rights. Missouri state law permits owner-occupants to perform residential work on single-family homes without a contractor license, as long as the work complies with code and the owner files for the appropriate permits. This is one of the more permissive owner-builder states in the country. However, electrical and plumbing work are always regulated trades — a licensed electrician and plumber must pull and supervise those subpermits, even on owner-builder projects. Missouri also does not require building permits for certain farm structures and minor repairs, but those exemptions are narrowly defined and don't apply within city limits; Union's local code takes precedence. Property owners should verify with the City of Union Building Department whether a specific project qualifies for an exemption before assuming no permit is needed.
Common questions
Do I need a permit for a deck in Union?
Yes. Any deck larger than 200 square feet or any deck attached to the house requires a permit. Many small detached decks under 30 inches in height may be exempt — check with the building department. Permit cost typically runs $75–$150 for a small deck. You'll need to submit a site plan showing the deck's location, dimensions, and distance from property lines and setback boundaries. Deck footings must go below the 30-inch frost line in Union.
Can I pull my own residential permit in Union if I'm the property owner?
Yes. Missouri law allows owner-occupants to pull residential permits and perform the work themselves on single-family owner-occupied homes. However, electrical and plumbing subpermits almost always require a licensed electrician and plumber, even on owner-builder projects. Contact the City of Union Building Department to ask whether your specific trade work qualifies for owner-builder status or requires a licensed contractor.
How long does a permit take to issue in Union?
Simple permits (fences, sheds, minor repairs) often issue over-the-counter the same day or within 1–2 business days. More complex projects (additions, electrical upgrades, HVAC) go through plan review, which typically takes 2–3 weeks. Expedited review is rarely available. Once issued, the permit is valid for 6–12 months depending on the project type — confirm the expiration date with the building department when you pick it up.
What happens if I don't get a permit?
If the city finds unpermitted work, you face a stop-work order, fines (typically $100–$500 per day of violation), and a requirement to obtain a retroactive permit and correction inspection. Unpermitted work can also affect your ability to sell the home — title companies often require proof of permits for major work. Getting a permit costs a few hundred dollars; fines and remediation cost thousands. The safe move is a quick phone call to the building department before you start.
Does Union require permits for roof replacement?
Yes. Roof replacements typically require a permit in Union, especially if the work includes structural changes or if the roof system is being changed (e.g., from asphalt shingles to metal). A simple re-roof with the same material type is sometimes exempt, but verify with the building department first. Permit cost for a roof typically runs $50–$150 depending on the roof area and whether new structural work is involved.
What's the frost depth in Union and why does it matter?
Union's frost depth is 30 inches. Any post, footing, or foundation element that supports a structure (deck posts, shed footings, fences, walls) must extend below 30 inches to prevent frost heave — the upward movement of soil as it freezes and thaws. Inspectors will verify footing depth during the foundation or footing inspection. Loess soil in Union's northern areas can be prone to settling; karst areas in the south have sink-hole risk. The building department may request geotechnical information for certain projects.
Do I need a permit for a shed in Union?
Most sheds require a permit. If the shed is over 100–200 square feet or attached to the house, a permit is almost certain. Very small detached sheds (under 100 sq ft) in some jurisdictions may be exempt, but Union's local code determines the threshold — call the building department. Shed permits typically cost $50–$100 and require a site plan showing location and setback distances.
Can I file my permit online in Union?
As of this writing, Union does not have a widely available online permit portal. You'll need to file in person at City Hall during business hours (Monday–Friday, 8 AM–5 PM, subject to local verification) or inquire whether mail-in filing is available. Call ahead to confirm current filing methods and bring all required documentation: completed application, site plan, electrical/plumbing plans if applicable, and contractor licenses if you're hiring out.
Get started with your Union permit
Contact the City of Union Building Department today. Call or visit City Hall to confirm the building department's phone number, address, and current hours. Have your property address, project scope, and site plan (or a rough sketch) ready. For most projects, the initial conversation takes 10–15 minutes and will tell you exactly what you need to file. If you're unsure whether you need a permit, ask — it's a free conversation and it protects you from fines and stop-work orders down the road.