Do you need a permit to replace a roof in St. Louis? Usually not in the city, and that is not the whole story

In the City of St. Louis, a straight like-for-like roof replacement does not require a building permit. That surprises most homeowners, and it surprises a lot of out-of-town crews too. The city's own residential permit criteria put roof replacement, when done with like material and replacement of 25 percent or less of the roof sheathing, on the no-permit list. What matters is the fine print, because the exact conditions that flip the rule into permit-required are the same two conditions that blow up a roofing bid.

In the City of St. Louis, a like-for-like replacement needs no permit

The city's Building Division publishes two lists: work that requires a residential permit and work that does not. Roof replacement appears on both, and the difference between them is a single clause.

On the no-permit list: roof replacement when done with like material and replacement of 25 percent or less of the roof sheathing. Also on that list, and worth knowing separately, are ordinary repairs to residential buildings and structures up to four units, plus window and door replacement that does not modify the opening.

On the permit-required list: an entire new roof, when roof work is not replacement of like material, and/or when more than 25 percent of the roof sheathing is removed and replaced.

If you are having asphalt shingles torn off and asphalt shingles put back on, and the crew is replacing a few bad sheets of decking rather than most of the roof, you are in the exempt column. The Building Division Permit Section sits at 1200 Market, Room 425, and takes questions at 314-622-3313 or stlcitypermits@stlouis-mo.gov, Monday through Friday, 8:00 to 4:30.

The two variables the rule actually turns on

Read the two lists next to each other and the logic is clean. St. Louis cares about exactly two things: whether the material is changing, and how much of the deck is coming off.

Those are also the two line items most likely to move the price of your roof after the contract is signed. Decking replacement is the classic change order. A bid says the roof is $14,000, then the tear-off exposes rotten sheathing around a chimney and a valley, and sheets get added at whatever the contract says a sheet costs. If the contract does not say, you find out at invoice time.

So the permit rule doubles as a bid-reading tool. If your roofer's estimate does not name a per-sheet decking price and a written cap or an approval step before extra sheets go on, the rule has told you where the risk lives and the bid has not answered it.

Historic districts run on a separate approval

This is the part that catches people in Soulard, Lafayette Square, Shaw, Compton Heights, and the rest of the city's designated areas. The city's own permit guidance says that properties in historic districts need approval for exterior work, including painting, windows, doors, gutters, and fences, even though it is not required by the Building Code.

The reviewing body is the Cultural Resources Office, described by the city as the preservation agency responsible for review of exterior work within the city's local historic districts, City Landmarks, public parks, and public buildings. Its review reach also covers Preservation Review Districts and National Register historic districts. The office is at 1520 Market Street, Suite 2000, and the number is 314-657-3865.

The practical version: a roof that is visible from the street in a designated district is a design question before it is a construction question, and the answer can rule out the shingle your roofer quoted. Ask the Cultural Resources Office first, in writing, and get the answer before you sign anything with a material name in it.

The city rule stops at the city line

St. Louis City and St. Louis County are separate jurisdictions, and the exemption above is a city rule. Cross into the county and you are dealing with either your own municipality's building department or the county's residential building section, depending on where your address sits and whether your municipality contracts with the county for code enforcement.

There is no shortcut here, and any roofer or blog that gives you one flat answer for "St. Louis" is guessing. The county publishes its own residential re-roofing guidance separate from the city's, and the municipalities inside it set their own thresholds and fees. Look up the actual jurisdiction for your address, call the building department listed there, and ask two questions: does a like-material re-roof require a permit, and does the contractor have to be registered or licensed with you to pull it.

Kansas City draws the same line at 32 square feet

Missouri's other big metro solves the same problem with a different number, which is a useful illustration of how local this all is. Kansas City's Building and Rehabilitation Code, Chapter 18 of the Code of Ordinances, exempts reroofing, meaning replacement of roof coverings, of one- and two-family residences with light roof covering, or reroofing of other structures done in accordance with the code's material and installation requirements.

Then it draws the boundary in the same sentence: exempted reroofing work does not include replacement of roof sheathing or deck, or structural modifications or alterations to the building. A separate exemption in the same list covers replacement of soffits and wall or roof sheathing under 32 square feet for one- and two-family dwellings, which is where the commonly cited threshold comes from. Decking work at or above that size needs a permit, and permit work means the contractor holds a current Kansas City business license. Structural work on rafters adds a residential contractor license and a scope or plan review on top.

The Permits Division is on the fifth floor of City Hall at 414 E 12th Street, reachable at 816-513-1500 or cdpermits@kcmo.org, and the city runs a separate Code Questions Hotline at 816-513-1511. The hotline is the right call when your question is "does this specific job need a permit" rather than "how do I apply."

In Joplin and most of Missouri, the license comes before the permit

Missouri issues no statewide roofing license, so in most of the state the question that matters more than the permit is whether the contractor is licensed in your city at all.

Joplin shows what that looks like in practice. A roofer working in the city holds a contractor license in the Subcontractor category for specialty work, which runs $150 for a full license year, prorated down to $37.50 for a three-month license issued between mid-February and mid-April. Behind the license sits a $10,000 license and permit bond, a certificate of liability insurance of at least $300,000 combined single limits naming the City of Joplin as certificate holder, and workers compensation coverage for any contractor with more than one employee. The license year runs April to April with the fee due April 15, and the Finance Department at 602 S Main Street handles it at 417-624-0820 ext. 1242. Permit questions go to the Building and Code Division at 417-624-0820 ext. 1521.

Notice what the bond is for. A license and permit bond exists so the city has recourse when a licensed contractor does permitted work badly or abandons it. It is not a warranty on your roof and it does not pay you directly, but it does mean the contractor put money and an insurance company's underwriting behind the license. A crew working without one has nothing at stake in your city except the check you are about to write.

Three questions the permit rule tells you to ask your roofer

The regulations above are really a map of where roofing jobs go wrong. Every threshold in them marks a place where the scope changes, the price changes, or somebody needs a credential they might not have. Three questions cover all of it.

1. Who pulls the permit if this job needs one, and in whose name. The answer should be the contractor, in the contractor's name. If they ask you to pull it as the homeowner, the reason is almost always that they cannot.
2. What does decking cost per sheet, and who approves it before it goes on. This is the 25 percent threshold and the 32 square foot threshold showing up in your wallet. Get a unit price and an approval step in writing.
3. Is this address in a historic or preservation district, and have you filed there before. A local contractor answers this in a sentence. A storm crew asks you what a preservation district is.

None of this requires you to become an expert in Missouri building code. It requires you to know that the rules are local, that they turn on material and decking, and that the contractor who cannot answer three plain questions about the jurisdiction they are standing in probably does not work there very often.