Window and siding replacement in Chesterfield
What the code and the permit desk actually require here — and what the houses in Chesterfield tend to be hiding behind the siding.
- People
- 49,574
- Homes
- 21,603
- Size
- 31.8 square miles
- From downtown
- About 25 miles west
- ZIP codes
- 63005, 63017
- Founded or incorporated
- 1988
Incorporated in 1988 out of several older communities, Chesterfield includes the Missouri River floodplain historically known as Gumbo Flats (now Chesterfield Valley). A violent F4 tornado cut a 21-mile path across St. Louis County on January 24, 1967, and the Gumbo Flats levee failed on July 30, 1993 -- the first levee failure there since 1935 -- flooding the valley; both are major, storm-relevant storm events in the city's history.
Chesterfield
The housing here is mostly built from the 1970s through the 1980s (about 32% in the 1970s, 23% in the 1980s).
What that vintage turns up
First-generation vinyl replacements went in across this whole period and they are now hitting both of the ages that matter at once: the frames are inside the twenty-to-forty-year band and the sealed glass units are well past the eight-to-twenty-year band. That combination produces the most common call we get on houses this age — fogged glass in a frame that is still perfectly sound. The honest first answer there is replacing the glass unit, not the window.
Hardboard and wood-composite lap siding from this era is the one with the paperwork. Masonite's hardboard covered product installed between 1980 and 1998 and reached roughly four million homeowners; Louisiana-Pacific's Inner-Seal siding had its own national settlement in the mid-1990s. Both claim programmes closed years ago, so the relevance now is diagnostic rather than financial: swelling, delamination and mushrooming along the bottom edges of the boards on a house of this age is a known product history, not necessarily the owner having neglected it.
The one to watch on a house of this age
Synthetic stucco applied before about 1997 is the high-risk cohort. Roughly ninety-five per cent of American applications were the face-sealed kind, which has no way to drain what gets past it, and the failures traced back overwhelmingly to flashing that was left out. Drainable systems are a different animal and are not the problem.
Lead paint. No, for anything built after 1978 — but confirm the build year before assuming it. 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.
Neighbourhoods
We work across Bellefontaine, Lake, Gumbo, Monarch and Bonhomme.
Next door
Chesterfield shares a boundary with Town and Country. Where we have a page for a neighbour it is linked; where we do not, the rules there are still different from the rules here.
The rules in Chesterfield
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
Chesterfield contracts with St. Louis County for building, residential and existing-building code enforcement, so the County’s exempt-work list and its U-0.34 window condition are what apply here. The city keeps property maintenance and land disturbance for itself. Chesterfield does not run a fully self-contained building department: City Code Section 500.020 provides that 'The City of Chesterfield, Missouri, is hereby authorized and directed to execute and enter into a contract on behalf of the City with St. Louis County, Missouri, for technical code enforcement services, which contract shall be on file in the City offices.' An editor's note confirms the current contract is on file rather than published, so the split between what the City handles and what County staff handle is not publicly documented. The city also runs a separate Architectural Review Process and a 'Planner of the Day' desk.
Who to call
- St. Louis County
- 314-615-5184 — Chesterfield has no building department of its own
- Official
- Director of Transportation and Public Works (Stephanie Leon Streeter, P.E.)
- Permits
- Department page
How Chesterfield 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 |
|---|---|---|---|
| Chesterfield | Depends | Depends | U-0.34 |
| Affton | Depends | Depends | U-0.34 |
| Ballwin | Yes | Yes | — |
| Brentwood | Yes | Not published | U-0.28 |
| 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 Chesterfield
Nothing completed in Chesterfield so far. Rather than pad this out, we have left it blank until there is a real job to describe.
Where these facts came from
Everything on this page about Chesterfield 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 · chesterfield.mo.us · chesterfield.mo.us · ecode360.com · ecode360.com · content.civicplus.com
Getting quotes in Chesterfield?
Ask every bidder what the permit and energy rules here are. Then ask us.
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