Attic insulation, air sealing, crawl spaces and walls for homes in Creve Coeur — starting with a free assessment that measures the R-value you actually have. Creve Coeur enforces the 2015 IECC, which sets R-49 for a new attic.
Creve Coeur runs to about 10 square miles and roughly 18,643 people. It sits about 13 miles west of downtown St. Louis. That is roughly 8,821 housing units. The community dates back to 1949. We cover ZIP code 63141.
Our job history shows nothing in Creve Coeur so far. Plenty of sites will show you a number here anyway.
The typical home in Creve Coeur dates to around the early-1980s. Houses of this vintage usually got batts or blown fiber at whatever the standard of the day was, which is well short of what is recommended now. Most are one top-up away from being right.
Predominantly 1960s-70s construction, with the single largest building wave in the 1970s (about 2,026 units).
Incorporated in 1949, Creve Coeur grew rapidly after Interstate 270 and U.S. Route 40 were built through it; a handful of cabins more than 200 years old still stand in Conway Park alongside the mid-century subdivisions that make up most of the city's housing stock.
The Census Bureau estimates 8,821 homes in Creve Coeur. 88 of them (1%) went up before 1940 — 34th of 44 places on this site for pre-1940 housing. The 1970s were the busiest decade, adding 2,026 of today's homes (23%); 51% predate 1980 and 22% were built in 2000 or later. For St. Louis County as a whole the pre-1940 share is 10%, so Creve Coeur sits below it.
Of 8,158 occupied homes, 55% heat with utility gas and 44% with electricity. Electric heat here is more common than across the county (23%), and ranks 7th of 44 on this site. Which utility program can contribute depends on the heating fuel and on who sends the bill, so that is the first thing an assessment pins down.
61% of occupied homes are owner-occupied and 51% of all homes are single-family detached houses. With houses like these, the conversations we expect most are about an attic top-up over postwar fiberglass and an energy assessment before deciding what to fix first.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 88 | 1% | |
| 1940s | 47 | 1% | |
| 1950s | 567 | 6% | |
| 1960s | 1,739 | 20% | |
| 1970s | 2,026 | 23% | |
| 1980s | 1,361 | 15% | |
| 1990s | 1,060 | 12% | |
| 2000s | 972 | 11% | |
| 2010s | 961 | 11% | |
| 2020 or later | 0 | 0% |
8,821 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 8,158 occupied.
2,421 of Creve Coeur's 8,821 homes (27%) were built in the 1980s and 1990s. The gaps in houses of that age are the parts nobody sealed: batts stuffed into the rim joist, bare spots over cathedral and tray ceilings, soffit vents buried with no baffles, can lights punched through the ceiling plane. A top-up plus a day of sealing usually covers it.
Creve Coeur enforces the 2015 IECC. City Code Section 500.1010, added by Ordinance No. 5692 dated 4-13-2020, adopts the document 'International Energy Conservation Code, 2015, Seventh Edition' as the Energy Conservation Code for residential and commercial buildings. The city's amendments in Sections 500.1020 through 500.1150 change only the administrative chapter (board of appeals) and the referenced-standards chapter, where St. Louis County mechanical and electrical codes are substituted.
For new work, the attic number under that edition is R-49, with walls at R-20, or R-13 plus R-5 continuous. Set that against the Department of Energy, which recommends R60 for an uninsulated attic in this climate zone and R49 for one that already has a few inches.
Table R402.1.2 of the 2015 IECC, climate zone 4 except marine, as published by the U.S. Department of Energy in 'Residential Provisions of the 2015 International Energy Conservation Code' (ceiling 49; wood frame wall 20 or 13+5).
There is no published answer for Creve Coeur. Neither the permit-required list nor the exemption list mentions insulation or air sealing at all. Insulation, air sealing and attic work appear on neither list. The handout states the lists are not all inclusive and directs questions to the Building Division at 314-872-2500. The building permit application's work-type checkboxes do not include insulation. That silence is not permission and it is not a prohibition. We settle it with a phone call before the crew is scheduled.
Nothing the city publishes on the Building Division page or the building permit application requires an insulation contractor to register or hold a city license. The application asks for the contractor's name and contact information but does not ask for a license number. The only licensing requirement stated on the application is that construction plans bear the seal of a registered Missouri design professional.
The published number is 314-872-2500. The department page is here.
Permitting is on us, not on you.
Creve Coeur is on the Missouri side, where most addresses buy their electricity from Ameren Missouri. Its Pay As You Save program publishes $0.20 per square foot on ceiling and attic insulation and $0.06 per square foot on air sealing for the 2026 program year; the incentive comes off the cost and the rest is repaid through a monthly charge on the bill. The conditions: an attic going from R-20 or below to at least R-38, air sealing that cuts measured leakage by 20 percent, and twelve months in the home. CommunitySavers can include attic insulation at no charge for income-eligible households. Income-qualified households can apply to Community Action Agency of St. Louis County (CAASTLC) (314-863-0015) for free weatherization instead. The St. Louis County page and the rebate guide carry the full rules.
Every layer of an insulated attic, explained
Creve Coeur borders Town and Country and Maryland Heights. These are the ones we also cover, each with its own energy code and permit rule:
Elsewhere in St. Louis County we also cover:
Missouri sets none of this at state level. Across the 7 places in this table there are 3 different adopted editions (2015 IECC, 2018 IRC ch. 11 and 2024 IECC), and 1 of the 7 publishes a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Creve Coeur | 2015 IECC | R-49 | Not published | 314-872-2500 |
| Town and Country | 2018 IRC ch. 11 | R-49 | Not published | 314-587-2820 |
| Maryland Heights | 2015 IECC | R-49 | Not published | 314-291-6550 |
| Affton | 2015 IECC | R-49 | Not for an attic top-up | 314-615-5184 |
| Ballwin | Not published | — | Not published | 636-227-2129 |
| Brentwood | 2024 IECC | R-49 | Not published | 314-963-8602 |
| Chesterfield | Not published | — | Not published | 636-537-4000 |
All 21 St. Louis County jurisdictions side by side →
Creve Coeur enforces the 2015 IECC, which sets R-49 for an attic in new work. That code also reaches work on existing houses, not only new ones.
Creve Coeur has not published a rule for it; the building department at 314-872-2500 is called before the job starts.
For most Ameren Missouri customers, Pay As You Save: $0.20 per square foot on an attic starting at R-20 or lower and $0.06 per square foot on air sealing in 2026, the rest repaid on the bill. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Creve Coeur dates to around the early-1980s; the Census Bureau's 2020-2024 median year built is 1980. Of its 8,821 homes, 1% went up before 1940 and 22% in 2000 or later. That is a median across the whole place, so your own house may be older or newer.
Code and permit facts checked September 10, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: ecode360.com (2, 3, 4) · crevecoeurmo.gov (2, 3, 4) · energycodes.gov · data.mo.gov · en.wikipedia.org · censusreporter.org · point2homes.com · ameren.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 314-872-2500 or your electric utility first.
Free assessment, a measured R-value, and photos you keep either way.
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