A building permit submittal package on a desk with rolled construction drawings, forms on a clipboard, and a hard hat.

Permitting & Approvals in Missouri

Missouri has no statewide residential building code, and no statewide mechanism for adopting one. Building-code authority is granted by the legislature to some counties and not others, and the grant is keyed to the county's statutory classification: under RSMo 64.170 only counties of the first and second classification may adopt a building code at all. On the Missouri Association of Counties' May 2025 classification list, 89 of Missouri's 114 counties are third classification and have no county building-code authority whatsoever. County zoning is a separate power under separate sections with its own referendum rules. So the first job on a Missouri parcel is not filling in a form. It is establishing who, if anyone, has authority over the land — and then dealing properly with the approvals that do apply, because "no building code" is not the same thing as "no rules."

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Permitting & Approvals: how the work runs

Four stages, in this order. The sequence matters more than it looks: getting engineering and permitting settled before anything is fabricated is what keeps a build from stalling.

1

Establish who has authority over your parcel

Three questions in order. Is the land inside a city, or unincorporated? If it is unincorporated, what is the county's classification — because RSMo 64.170 grants building-code authority only to first- and second-classification counties, and fourth-classification counties operate under second-class law. Is it one of the five charter counties, which sit outside the classification system altogether and take their authority from their own charters under Article VI of the state constitution rather than from 64.170? Two Missouri traps get checked here as a matter of course. The City of St. Louis is recognised by the constitution as both a city and a county, and is not part of St. Louis County — nothing one adopts applies in the other. And Kansas City sits in four counties, so a city address does not settle the county question either.

2

Zoning, and the agricultural exemption that does not cover a house

Zoning is a different power from a building code, under different sections, with different rules — and a reader in a third-classification county can face a zoning setback with no building inspection at all, because those counties can zone after a vote even though they cannot have a building code. Where county zoning exists, Missouri does carry an agricultural exemption, and it is where most buyers' plans break. The exemption in RSMo 64.620(2) covers the raising of crops, livestock, orchards or forestry, and the erection or extension of farm buildings or farm structures "used for such purposes." A dwelling is not the raising of crops, livestock, orchards or forestry — and the same section lists residence separately, as a use the county may regulate. The exemption also stops at the flood hazard area map: inside the mapped area it does not apply at all. We read the district text and the county's actual position rather than assuming from the tax bill.

3

Line up the approvals that genuinely apply

In a county with no building code the build is not ungated — the gates are just somewhere else. The wastewater construction permit is the primary one and it is statewide: RSMo 701.046 requires notification and a construction permit before a system is built, and the words "or department" carry it, because where a county runs no programme of its own the Department of Health and Senior Services is itself the permitting authority. There is no gap. Then, if any of the site is in a Special Flood Hazard Area and the community participates in the National Flood Insurance Program, a floodplain development permit from the local administrator. Then the entrance: MoDOT for a state route, the county road authority otherwise. Then a 911 address, which is real in some counties and absent in others. Then the electric utility, which will enforce its own meter-base specification and nothing behind it. We establish which of those apply before anything is scheduled.

4

Submittal, review and whatever inspections exist

Where the jurisdiction has adopted a code, the edition it adopted is the edition your drawings answer to — and that is not necessarily a recent one. RSMo 64.196 requires only that a county adopting a code adopt a "current, calendar year 1999 or later edition, nationally recognized building code, as amended", with no state review and no adoption cycle, so a Missouri county lawfully running an early-2000s edition is fully compliant. That matters because the design criteria on your drawings — wind, snow, frost depth, seismic category — come from that edition's own table in that jurisdiction, not from any state figure. We get that table in writing, build the submittal around it, and carry the review comments. Where nothing has been adopted, there is no submittal and no inspector, and the honest conversation is about what independent checks you want to commission instead.

Overhead view of architectural floor plan and structural elevation drawings spread on a workbench with a scale ruler and pencil.
The question that comes before the permit

In 89 of Missouri's 114 counties, the county is not legally allowed to have a building code at all

Missouri does not decide this county by county on the merits. It decides it by classification. RSMo 64.170 empowers "the county commission in all counties of the first and second classification" to regulate construction, issue building permits and set inspection fees — and RSMo 64.205 closes the door from the other side in a single sentence: sections 64.170 to 64.200 "shall apply to all counties of the first and second class." Now the part almost nobody knows. A Missouri county's classification is set by its assessed valuation, not its population, under RSMo 48.020, with the dollar thresholds indexed annually to inflation by the State Tax Commission. That is why Camden County, population 44,135, is a first-classification county holding exactly the same statutory class as Boone County at 192,154. Class is not a proxy for size, and you cannot infer it from a map. There is a second lock. RSMo 64.170(2) provides that a county which had not adopted a building code before 28 August 2001 has no authority to adopt one unless the voters approve it — and subsection 3 puts the question only to voters in the area affected, so a county code is voted on by the unincorporated electorate alone. And Missouri's five charter counties — Clay, Jackson, Jefferson, St. Charles and St. Louis — are outside the classification system entirely and draw their authority from their own charters, not from 64.170. Which of these your land sits in is the single most consequential fact about your build, and it is knowable in an afternoon.

Where we deliver permitting & approvals

In Missouri the county line is a real boundary, and unusually it can decide whether there is a building code on your side of it at all. Only first- and second-classification counties may adopt one, and classification is set by assessed valuation rather than population — so a small county can have the authority while a much larger one does not. Cross a line and what changes is whether the build is inspected, who reviews the drawings, what they charge, how the land is zoned, and the design figures the work is engineered to. Two parcels twenty miles apart can carry completely different engineering, and sometimes completely different paperwork.

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Every locality we build in has its own reviewer, its own fee schedule and its own filled-in design criteria. The service area pages set out what each one publishes.

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What actually decides the price

Square footage is the number everyone leads with, and it is rarely the one that moves a barndominium budget. These four do.

  • Which authority you are actually dealing with

    Whether the parcel is inside a city, in an unincorporated county with a building code, or in an unincorporated county that has no authority to have one changes the whole scope of this work. Fee schedules are set by the jurisdiction, not by the state, and there is no statewide fee to quote. Worth knowing that a Missouri "building permit" does not always mean a code permit: RSMo 137.177 — a section of the taxation title, not the planning title — lets certain second-class counties require a permit before erecting a building costing over six hundred dollars outside city limits, issued by the county clerk on payment of a five-dollar fee, with the list of permits delivered to the county assessor twice a year. There is no code, no plan review and no inspection in it. It exists so the assessor learns about the improvement.

  • Whether zoning applies, and what your district says

    County zoning in Missouri exists only where the county's voters approved it, and it can be repealed the same way — RSMo 64.695 puts termination on the ballot on a petition of five percent of the county's vote for governor at the last gubernatorial election, and if it carries, every resolution, ordinance and regulation adopted under the programme is void and of no effect. So "does my county have zoning" is a live, county-specific question rather than a background fact. Where it exists, the district text drives setbacks, minimum lot area and whether a shop and a dwelling can share a parcel, and reading it is the work.

  • Flood status, because it removes exemptions rather than adding steps

    Inside a mapped Special Flood Hazard Area two things change at once. FEMA and SEMA's Missouri guidance requires a local permit before construction of agricultural buildings and any land-disturbing activity, says non-elevated agricultural structures may be permitted only by variance, and states plainly that farm houses are not agricultural structures. And Missouri's own zoning exemption for farm buildings applies only in an area not within the area shown on the flood hazard area map — so the exemption people rely on is switched off in exactly the river-bottom acreage they are most often shown.

  • Whether a sealed submittal is required where you are building

    Missouri exempts a dwelling house from the requirement to use a licensed architect or professional engineer, provided the drawings state that the person is not licensed as such — that is RSMo 327.101.2(5)(a) for architecture and 327.191.2(5)(a) for engineering. Separately, some jurisdictions require seals of their own: Greene County states on its own page that design documents for commercial plan submittal must be sealed by a design professional licensed with the State of Missouri, and Platte County's building permit packet requires sealed drawings by a Missouri-licensed engineer and site plans by a Missouri-licensed surveyor for various permit types. Where a seal is required, structural design and sealing are provided by a Missouri-licensed professional engineer engaged for that purpose.

A building permit submittal package on a desk with rolled construction drawings, forms on a clipboard, and a hard hat.

Permitting & Approvals in Missouri: common questions

8 questions we get asked most often about building in Missouri. If yours is not on the list, ask it directly.

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Do I need a building permit for a barndominium in Missouri?
There is no single Missouri answer, and any builder who gives you one has not checked. Missouri has no statewide residential building code, so the question resolves to who has authority over your particular parcel. If the land is inside a city, the city's own ordinances govern; Missouri gives every city, town and village general zoning power under RSMo 89.020 with no class test and no referendum. If the land is unincorporated, the county can only have a building code if it is of the first or second classification under RSMo 64.170 — fourth-classification counties operate under second-class law and fall inside the grant, third-classification counties do not — or if it is one of the five charter counties working from its own charter. There is a further catch worth knowing even where a permit exists. In Missouri a permit does not necessarily mean a code, a plan review or an inspection. RSMo 137.177 sits in the taxation title and lets certain second-class counties require a permit before erecting a building costing more than six hundred dollars outside city limits; the clerk issues it for five dollars and sends a list to the assessor twice a year. That permit exists so the county learns about the improvement, not so anyone checks it. "Do I need a permit" and "will anyone look at my building" are two different questions in this state, and we answer both.
Why does my county have no building code when the next county over does?
Because Missouri keys the power to the county's statutory classification, and classification is set by assessed valuation rather than by population. RSMo 48.020, as amended effective 28 August 2026, puts first classification at an assessed valuation of nine hundred million dollars and over, second classification at six hundred million up to that threshold, and third classification below it — with the thresholds indexed annually to the consumer price index and published by the State Tax Commission, so the statutory dollar figures are floors rather than current numbers. The result is genuinely counter-intuitive. Camden County, with 44,135 people, is a first-classification county — the same class as Boone County at 192,154 — because of what the Lake of the Ozarks does to its assessed valuation. Class is not a proxy for size. Missouri's five charter counties, Clay, Jackson, Jefferson, St. Charles and St. Louis, are a separate matter again: the constitution puts a chartered county outside the classification system entirely, so their authority comes from their charters. Two further points that decide real cases. RSMo 64.170(2) provides that a county which had not adopted a building code before 28 August 2001 has no authority to adopt one unless the voters approve it, and only the voters in the unincorporated area affected get to vote. And RSMo 48.030 lets a county's own governing body elect to move up to first classification as soon as it qualifies, without waiting the usual five years — so a county can acquire the power to have a building code by its own vote. That is also why any statement of a county's class needs a date on it. Ours are dated to the Missouri Association of Counties' May 2025 list.
It's agricultural land. Doesn't that exempt the building?
This is the most expensive misunderstanding in Missouri, and it fails in two separate places. First, the agricultural exemption people are thinking of is an exemption from county zoning, not from a county building code. The exemptions live in the planning-and-zoning enabling acts — RSMo 64.620(2) for second and third classification counties, 64.890(2) in the alternative programme, 64.090(2) for first-classification charter counties. The building-code sections are a different, earlier group, RSMo 64.170 to 64.207, and no section in that group exempts farm buildings, agricultural buildings or agricultural land from anything. RSMo 64.170 empowers regulation of "any building or structure" without qualification. The only nearby farm exemption, RSMo 64.003 effective 28 August 2025, is expressly limited to county fire protection and fire prevention ordinances and does not reach a building code. Second, even the zoning exemption does not reach a house. It covers the raising of crops, livestock, orchards or forestry, and farm buildings or farm structures "used for such purposes" — and living in a building is not raising crops, livestock, orchards or forestry. The same section of the statute lists residence separately, among the uses a county may regulate. And the exemption applies only in an area not shown on the flood hazard area map, so on bottomland it is switched off altogether. If it helps, look at what Missouri's own tax code does, because it is the most farmer-friendly definition in the statute books: RSMo 137.016 defines agricultural and horticultural property to include buildings and structures customarily associated with farming — and then RSMo 137.017 adds their value to the agricultural land value "excluding residential dwellings and related land." Missouri's assessor separates the house from the farm. A zoning administrator is not going to be more generous. One honest caveat: "farm building" is not defined anywhere in RSMo Chapter 64, so the reasoning above is what the statute says rather than a prediction of how any particular county will rule on your building.
Missouri's constitution has a right to farm. Doesn't that protect me?
It exists, it is real, and it does not do this job — and the reason is on the face of its own text. Article I, Section 35 of the Missouri Constitution, adopted in 2014, guarantees "the right of farmers and ranchers to engage in farming and ranching practices" — and then, in the same sentence, makes that right "subject to duly authorized powers, if any, conferred by article VI of the Constitution of Missouri." Article VI is the local government article. It is the article that contains the county charter powers and the county classification system that produce building-code and zoning authority in the first place. So the right to farm is expressly subordinate to county and municipal power, not superior to it. Missouri's courts have already applied that: the Revisor's own annotation on that section cites Vimont v. Christian County Health Dept., 502 S.W.3d 718 (Mo. App. S.D. 2016), holding that the right to farm provision does not invalidate a county ordinance duly authorised under Article VI powers. And in any case the provision protects farming and ranching practices. Building a house is not a farming practice.
If my county has no code, who actually inspects my building?
On the building itself — nobody. That is worth saying plainly, because it is the single most important thing a rural Missouri landowner can know before committing money. The build is not ungated; the gates are simply elsewhere. The wastewater construction permit is the primary one and it is genuinely statewide: RSMo 701.046 requires an application and a construction permit before an on-site sewage system is built, and where a county runs no programme of its own the Department of Health and Senior Services is itself the permitting authority — there is no gap. That permit carries a real pre-closure inspection under RSMo 701.050, with notice due before nine in the morning on the day preceding completion for a registered contractor and the system held open until three on the day of completion. But it inspects the septic system. A floodplain development permit applies only inside a Special Flood Hazard Area in a community that participates in the flood insurance programme. A driveway permit inspects the entrance. And the electric utility inspects the meter base and nothing behind it: Cuivre River Electric Cooperative's rural residential installation guide says the meter base is inspected "if required by the city or county" and lists unincorporated Lincoln County as "Not required," while Platte-Clay Electric Cooperative states in its engineering rules that it "does not inspect the members' wiring for compliance with requirements of electrical codes or regulations established by public bodies." Missouri's Office of Statewide Electrical Contractors is equally direct in its own FAQ: "The state will not be issuing permits nor will the state be inspecting the work performed." So in much of rural Missouri the septic permit, the floodplain permit and the driveway permit are real and enforced, and none of them looks at your framing, your foundation, your roof or your wiring. If you want this building checked, that has to be arranged deliberately — and it is worth arranging.
Do I need a licensed contractor in Missouri?
There is no statewide general contractor or residential builder licence in Missouri to hold. The Missouri Division of Professional Registration's boards include architects, engineers, land surveyors and landscape architects, electrical contractors, real estate appraisers and dozens of others — and no general contractor, residential builder, home improvement, plumbing or mechanical board. RSMo Chapter 324's only construction-trade heading is electrical contractors. But "Missouri doesn't require a licence" is the answer most competitors give and it is false in several of the places people actually build. Kansas City requires a Residential Building Contractor licence to contract to construct, structurally alter or enlarge any one- or two-family detached dwelling or townhouse — and also for a detached accessory building over 400 square feet — with a qualified supervisor holding a city certificate of qualification and a liability policy with a minimum aggregate limit of one million dollars per occurrence. Independence licenses in four classes and requires either a 75 percent passing score on a nationally recognised examination or a bachelor's degree in engineering, architecture or construction science, plus five hundred thousand dollars of general liability including completed operations. The City of St. Louis requires a Construction Industry Contractor Graduated Business License from the License Collector, with no dollar or scope threshold at all. Meanwhile St. Charles County licenses electricians, plumbers, mechanical contractors, pool installers, drainlayers, third-party inspectors and blasters but not general contractors; unincorporated Greene County states that its only licensing requirement is that wastewater installers be county- and state-certified; and in unincorporated Jackson County electrical, mechanical and plumbing work has required a Class A or B licence since 28 January 2014. On the electrical side specifically, Missouri's statewide electrical contractor licence is optional rather than mandatory: RSMo 324.920(4) says a contractor working in a political subdivision that requires no local licence is not required to hold the statewide one. Two things worth having in mind separately from any of that. Missouri requires a construction-industry employer with one or more employees to carry workers' compensation, where most other Missouri employers are not required to until they have five. And any Missouri city or county that issues a business licence to a construction contractor must collect a workers' compensation certificate or a signed exemption affidavit before issuing it.
Can my county force me to install fire sprinklers?
No — and this is one of the very few things Missouri genuinely says about every new house in the state, which makes it unusually safe to rely on. RSMo 67.281 requires a builder of one- or two-family dwellings or townhouses to offer the purchaser the option, at the purchaser's cost, to install fire sprinklers, on or before the time the purchase contract is entered into. Then it goes further: notwithstanding any other provision of law, no purchaser of such a dwelling "shall be denied the right to choose or decline to install a fire sprinkler system" by any code, ordinance, rule, regulation, order or resolution of any county or other political subdivision. So the choice is yours, statewide, and no Missouri city or county may make residential sprinklers mandatory in a new one- or two-family dwelling. It is worth pairing that with the other place people expect a state mandate and do not get one. Missouri does have a statutory seismic requirement, RSMo 319.200 to 319.207, aimed at jurisdictions likely to experience severe shaking from a New Madrid event — but RSMo 319.203 exempts any private structure under ten thousand square feet and exempts "any single-family or duplex residence" outright, and expressly does not require the political subdivision to establish an inspection programme. Missouri's state-level rules about houses are few, and they mostly run in the direction of leaving the decision with you.
What should I have in writing before I buy the land or pay anyone a deposit?
Seven items on the parcel, and one on the contract. On the parcel: the county's current classification and whether it has adopted a building code, with the date of the answer, because class moves and the state's own published dataset of county building codes was last updated in 2021. Whether county zoning exists and, if it does, the district your parcel is in and the text of that district. The wastewater authority for your county from the Department of Health and Senior Services' own county selector — its onsite programme, a local authority under contract, or a local authority under its own ordinance — and whether the lot is three acres or more, because RSMo 701.031 can exclude a single-family lot of that size from the state programme entirely. Your flood zone, and separately whether the county participates in the National Flood Insurance Program at all, because in a Missouri county without planning and zoning the voters had to authorise floodplain regulations under RSMo 49.600 and can rescind them by petition. Who issues the driveway or entrance permit — MoDOT for a state route, the county road authority for a county road, the owners for a private one. Whether a 911 address is required and who assigns it. And, if the jurisdiction has a code, its Table R301.2(1) design criteria sheet in writing: that one page settles wind, snow, frost depth, seismic category and termite in a single document, and it is the only legitimate source for those figures — there is no Missouri number. On the contract side, know this before you pay anybody anything: RSMo 429.012 requires every original contractor, before receiving payment of any kind, to give the owner a written NOTICE TO OWNER in ten-point bold type explaining that unpaid suppliers and subcontractors can file a mechanic's lien on your property and that you may ask for lien waivers. Giving that notice is a condition precedent to the contractor's own lien rights. If a Missouri builder takes your deposit without it, that tells you something.

Keep reading

The pages that answer the next question this one raises.

Is It Legal in Missouri?

Most counties have no building code at all, whether yours may adopt one, and where the agricultural exemption stops.

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How Long Does It Take?

The 30-business-day statutory review clock, and how the private-provider route shortens it.

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Where We Build

Which authority actually reviews your parcel, city by city.

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