Do you need a permit? It depends which side of the street you are on.

There is no single answer to “do I need a permit to replace my siding in St. Louis,” and anyone who gives you one has not looked. Missouri has no statewide building code. Adoption happens municipality by municipality, and the municipalities here do not agree with each other about very much.

We looked up all 45 of the cities and counties we work in, one at a time, reading each one's own published permit language rather than repeating what other sites say. We have a documented answer on siding for 37 of them. Where we do not, this page says “not published,” which is the honest answer and not the same as “no permit needed.”

The whole table

Click any place for the published wording, the fee basis, the phone number and the sources.

The five patterns underneath it

1. The exempt list

Most jurisdictions adopt the International Residential Code, whose Section R105.2 carries a closed list of work that needs no permit — accessory sheds, fences, retaining walls, sidewalks, painting and papering, and so on. Siding and window replacement are not on that list. So under the model code, both need a permit. What varies is what each city did to the list afterwards.

St. Louis County added to it, generously: “Siding: new or replaced exterior siding (vinyl, metal, wood, hardboard, etc.) including replacing with a different type of siding” sits among the ordinary repairs it exempts. Edwardsville went the other way and deleted the residential exemptions outright — “Section R105.2 Work exempt from permit. Delete Buildings — exemptions 1-10.” Nothing survives. Those two are twenty-five miles apart.

2. The money threshold

Several places skip the list entirely and use a dollar figure. Ballwin: a permit is required when the cost of the work “exceeds $100.00.” Granite City: “any building repair or series of repairs, costing over eight hundred dollars.” Collinsville exempts “minor repairs made at a cost of less than five hundred dollars.” Every real re-side clears all three. A single window might not.

3. The city that does not issue permits at all

Manchester says the function “is handled by other separate jurisdictions.” Wildwood does zoning review and sends applicants to County Public Works. Chesterfield contracts the County for technical code enforcement. If you are in one of those, the rule that governs your job is St. Louis County's, not your city's — and the County's rule is unusually permissive.

4. The condition attached to the exemption

This is the one that catches people. St. Louis County exempts window replacement in the existing rough opening only if the new windows are “the manufacturer's largest standard size window that will fit within the existing opening,” are of the same operating style or one giving an equal or greater opening area, carry “a maximum U-Factor of 0.34,” and meet safety glazing. Miss any of those and the exemption is gone. It also requires a permit to replace a window with a style that gives a smaller opening area — a rule aimed squarely at people swapping a casement for a double-hung and quietly losing their egress.

Florissant attached an aesthetic condition instead: removal and installation of exterior coverings is exempt, but only where the new covering matches the existing “in appearance and color, texture and profile so as not to promote visual blight.” Change the colour and you are back in permitting.

University City runs it backwards from what installers expect. Vinyl or pre-finished metal siding over existing walls with no change to openings is exempt; “the addition, removal, or change-out of any type of glazing in the thermal envelope” is not. Re-side freely, permit the windows.

5. Historic district review, which sits on top of all of it

In the City of St. Louis, a property in a City Historic District needs a permit for all exterior work except painting wood trim — including work the building code itself exempts. So the same window replacement that needs nothing three blocks away needs Cultural Resources Office approval in Soulard. The historic district guide covers which local rules bite and which are only advisory.

What about a licence?

Missouri licenses no siding contractors and no window installers. The Division of Professional Registration runs 42 licensing boards and the only construction trade among them is electrical contracting. There is no state licence, no state registration, no exam and no bond.

Illinois licenses roofing contractors under the Roofing Industry Licensing Act, and nothing else in the exterior trades. The Act defines roofing work as work on a roof; siding and windows appear nowhere in it. A contractor who re-sides or re-windows a house in Madison or St. Clair County needs nothing at all from the State of Illinois.

Which means the licence that matters here is municipal, and it changes at every city limit. Which leaves municipal registration doing all the work, and it is patchy: Webster Groves requires a Certificate of Registration before any contractor does permit-worthy work. Ballwin requires a city licence and an active St. Louis County licence “in their respective field of expertise” — a requirement with nothing for a siding contractor to satisfy, since the County licenses only mechanical, electrical and plumbing. Granite City does not license at all but will refuse a permit to any contractor without a million dollars of general liability cover. Most of the rest publish nothing.

Sources: pr.mo.gov · idfpr.illinois.gov · law.justia.com