Window and siding replacement in Affton
What the code and the permit desk actually require here — and what the houses in Affton tend to be hiding behind the siding.
- People
- 19,052
- Homes
- 9,092
- Size
- 4.6 square miles
- From downtown
- About 8 miles south
- ZIP codes
- 63123, 63125
Affton is an unincorporated CDP named for postmaster Johann Aff; its median housing construction year is 1958, reflecting a classic postwar St. Louis County inner suburb.
Affton
The housing here is largely postwar, with the single largest decade of construction in the 1950s (about 31% of homes).
What that vintage turns up
The original units are single-pane — wood double-hungs on the frame houses, and steel casements on a good number of the brick ones. Steel casements rust along the bottom of the sash and frame first, the exterior putty fails, and the sash goes out of true until there is a visible gap along the closing edge. They are worth knowing about because they are a real decision rather than an obvious one: the National Park Service documented a job repairing sixty-five of them at roughly $360 a window, which was about what replacing them would have cost, and the replacements could not match the narrow original sightlines and cut the glass area by a fifth.
This is asbestos-cement shingle country. The grey or pastel shingles with the wavy bottom edge on so many houses of this age are a Category II non-friable asbestos material, and they are perfectly inert until somebody breaks, saws, sands or power-washes them, at which point the work practice itself is what makes them regulated. Missouri exempts a single house of four units or fewer from the inspection and notification requirements, which makes the paperwork disappear and does nothing at all to the material. Get it tested before anyone touches it.
The one to watch on a house of this age
Low-slope porch roofs tying into a wall are the classic leak on this vintage, and the tie-in is exactly where a kickout flashing belongs and usually is not. Whatever is going on behind that wall has been going on for a while.
Lead paint. Near certain. These houses predate 1978 by a wide margin. 69.2% of the homes in St. Louis County were built before 1980, and on anything pre-1978 the EPA renovation rule applies to both of these trades. Window replacement is never exempt from it, at any size — a single window triggers it. A whole-house re-side clears the twenty square foot exterior threshold on the first wall. What the rule actually requires of a contractor.
The rules in Affton
Siding replacement Conditional
St. Louis County lists re-siding among the “ordinary repairs or minor work for which a building permit will not be required.” The published item reads: “Siding: new or replaced exterior siding (vinyl, metal, wood, hardboard, etc.) including replacing with a different type of siding.” Adding exterior wall insulation under the new siding is exempt too — but insulating the inside face of the same wall is not. The exemption does not reach damage repair: a permit is required to repair a building damaged by termites, fire, wind, flood or earthquake, no matter how small the damage.
Window replacement, same opening Conditional Enlarging or cutting an opening Permit required
Replacing windows inside the existing rough openings is exempt from permit only if the new windows clear three published conditions: they are “the manufacturer’s largest standard size window that will fit within the existing opening” and match the old operating style or give an equal or greater opening area; they have “a maximum U-Factor of 0.34”; and they meet safety glazing where it applies. Glass-only replacement in an existing sash, and storm windows and storm doors, are exempt outright. A permit is required to enlarge or modify a rough opening — and also, unusually, to replace a window with a style that gives a smaller opening area than the one it replaces.
A replacement window here has to be U-0.34 or lower
St. Louis County adopted the 2015 I-codes by Ordinance 27,654, passed 18 December 2019 and effective 1 July 2020 (moved from 1 April 2020 because of Covid). It adopted no standalone energy code: one- and two-family dwellings are permitted to comply through Sections N1101 and N1102 of the International Residential Code instead. The number the County actually enforces on a replacement window is the one written into its own permit-exemption text — U-0.34.
0.34 is the County’s own published figure, taken from the condition it attaches to the window permit exemption rather than from an IECC table.
For comparison, ENERGY STAR asks for U-0.25 or lower with an SHGC of 0.40 or lower everywhere in this metro, which is stricter than every code edition in force here. And the code only bites when the sash and the glazing are replaced together — replace the glass alone in an existing sash, or add a storm window over the top, and it does not apply.
Contractor registration No
St. Louis County licenses mechanical, electrical and plumbing contractors and nothing else. There is no general contractor category and no siding or window category, so a siding or window company can pull a County permit with no County trade licence at all. Individual municipalities may still require their own business licence.
What the permit costs
Valuation-based. The fee comes off the residential table at SLCRO 1100.060, applied to the total estimated cost of work including labour and materials, plus a $47 permit processing fee.
Local quirks
Affton is unincorporated, so St. Louis County is its building department and there is no city hall to call. Affton is an unincorporated census-designated place, not a municipality. It has no city government, no building department and no municipal code; permits for single-family work are issued by the St. Louis County Department of Transportation and Public Works, Residential Building section. That establishes the county ordinance number and date but not the I-Code editions behind it, not the permit-exemption list, and not any energy code.
Who to call
- St. Louis County
- 314-615-5184 — Affton has no building department of its own
- Official
- Director of Transportation and Public Works (Stephanie Leon Streeter, P.E.)
- Permits
- Department page
How Affton compares with the rest of St. Louis County
Same county, same climate, same houses. Not the same rules.
| Place | Permit to re-side | Permit for a window | Window must meet |
|---|---|---|---|
| Affton | Depends | Depends | U-0.34 |
| Ballwin | Yes | Yes | — |
| Brentwood | Yes | Not published | U-0.28 |
| Chesterfield | Depends | Depends | U-0.34 |
| Clayton | Yes | Yes | U-0.30 |
| Creve Coeur | Not published | No | U-0.35 |
| Des Peres | Yes | Yes | U-0.32 |
| Ellisville | Not published | Not published | — |
| Eureka | Depends | Depends | — |
| Florissant | Depends | Yes | U-0.30 |
| Kirkwood | Not published | Not published | U-0.30 |
| Manchester | Depends | Depends | U-0.34 |
| Maryland Heights | Not published | Yes | U-0.35 |
| Mehlville | Depends | Depends | U-0.34 |
| Oakville | Depends | Depends | U-0.34 |
| Richmond Heights | Not published | Not published | U-0.28 |
| Town and Country | Depends | No | — |
| Unincorporated St. Louis County | Depends | Depends | U-0.34 |
| University City | Depends | Yes | U-0.32 |
| Webster Groves | Yes | Yes | U-0.35 |
| Wildwood | Depends | Depends | U-0.34 |
Work we have done in Affton
None logged in Affton yet. When there is one it goes here, with the address block and what was actually done to it. An empty section is better than a number you cannot check.
Where these facts came from
Everything on this page about Affton was read off a published source. Where a question has no published answer we have said so rather than filling the gap.
Sources: stlouiscountymo.gov · stlouiscountymo.gov · library.municode.com · ecode360.com · ecode360.com · ecode360.com
Windows or siding in Affton?
Tell us the address. We look up what the city requires before we work out a price.
Tell us about the house
We answer the phone. If we miss you, we call back.