Insulation and air sealing for Maryland Heights homes: attics, crawl spaces, rim joists and walls, starting with a free assessment of the R-value you actually have. Maryland Heights enforces the 2015 IECC, which sets R-49 for a new attic.
Maryland Heights runs to about 23 square miles and roughly 28,284 people. It sits about 15 miles northwest of downtown St. Louis. There are around 13,108 housing units here. The community dates back to 1985. We cover ZIP codes 63043 and 63146.
We have not logged a completed job in Maryland Heights yet. We would rather say so than put a number on this page that is not real.
The typical home in Maryland Heights dates to around the mid-1970s. Postwar building here often meant three or four inches of fiberglass and no attempt at air sealing. If nobody has touched it since, that is what is still up there.
Much of the housing predates the city's comparatively late 1985 incorporation, when the area was still unincorporated St. Louis County land.
That includes Riverport. Housing age and construction shift across Maryland Heights, sometimes by decades within a few streets, which is why we look in the attic before quoting rather than after.
Maryland Heights is anchored by the Riverport entertainment/commercial district (Hollywood Casino, the Maryland Heights amphitheater) near I-270 and the Missouri River bottoms.
The Census Bureau estimates 13,108 homes in Maryland Heights. 178 of them (1%) went up before 1940 — 33rd of 44 places on this site for pre-1940 housing. The 1960s were the busiest decade, adding 3,743 of today's homes (29%); 61% predate 1980 and 12% were built in 2000 or later. For St. Louis County as a whole the pre-1940 share is 10%, so Maryland Heights sits below it.
Of 12,592 occupied homes, 60% heat with utility gas and 38% with electricity. Electric heat here is more common than across the county (23%), and ranks 13th of 44 on this site. That is why the assessment asks how the house is heated: the fuel and the name on the utility bill decide which program, if any, can pay toward the work.
57% of occupied homes are owner-occupied and 50% of all homes are single-family detached houses, with 96 mobile homes in the count. 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 | 178 | 1% | |
| 1940s | 250 | 2% | |
| 1950s | 842 | 6% | |
| 1960s | 3,743 | 29% | |
| 1970s | 3,041 | 23% | |
| 1980s | 2,623 | 20% | |
| 1990s | 882 | 7% | |
| 2000s | 778 | 6% | |
| 2010s | 577 | 4% | |
| 2020 or later | 194 | 1% |
13,108 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 12,592 occupied.
7,626 of Maryland Heights' 13,108 homes (58%) date from 1950 through 1979. The leaks in houses of that era repeat: nothing over the top plates, wire and pipe holes left open, an unsealed hatch, a bath fan venting into the attic, and in ranches and split-levels, heat lost at the garage ceiling and over cantilevered floors. Sealing the plates, holes and fans comes before any more fiber, and it is usually a day's work, not a renovation.
Maryland Heights enforces the 2015 IECC. The city's Building Division page states that Maryland Heights adopted the 2021 International Code Council family of codes with the exception of the International Energy Code, which will remain 2015 as amended. The adopting ordinance is posted on the city site as 2024-4872, Adopting 2021 ICC Codes. The city's amendments to the 2015 energy code were not read.
Under that edition the required attic value for new work here is R-49, and walls R-20, or R-13 cavity plus R-5 continuous. For comparison, the Department of Energy recommends R60 for an uninsulated attic in climate zone 4A, where Maryland Heights sits, and R49 where there are already a few inches up there.
2015 IECC Table R402.1.2, climate zone 4 (except marine), as reproduced in the U.S. Department of Energy / PNNL Building America Solution Center comparison of 2009-2021 IECC and IRC minimum insulation requirements. The city keeps the 2015 energy code 'as amended' and those amendments were not read.
Maryland Heights publishes no answer either way. Insulation and air sealing appear on neither the permit-required list nor the exempt list. Insulation, air sealing and weatherization are not named, and the city publishes no exemption list. We confirm it with the department before we start and pull whatever is needed. We would rather write that here than guess on your behalf.
The Building Division page does not describe a city contractor registration or licensing program. It advises homeowners to confirm a contractor has the licenses and insurance needed to work in the region and points to state licensing agencies and the Better Business Bureau, which is not the same as a city requirement.
The published number is 314-291-6550. The department page is here.
Permitting is on us, not on you.
Maryland Heights 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
Maryland Heights borders Creve Coeur and Bridgeton. 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, 2021 IECC 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. |
|---|---|---|---|---|
| Maryland Heights | 2015 IECC | R-49 | Not published | 314-291-6550 |
| Creve Coeur | 2015 IECC | R-49 | Not published | 314-872-2500 |
| 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 |
| Clayton | 2021 IECC | R-60 | Not published | 314-290-8463 |
All 21 St. Louis County jurisdictions side by side →
Maryland Heights enforces the 2015 IECC, which sets R-49 for an attic in new work. Whether it reaches a retrofit of an existing house is not published.
Maryland Heights publishes no rule either way, so we ask its building department at 314-291-6550 before the job is scheduled.
Ameren Missouri's Pay As You Save: $0.20 per square foot for an attic starting at R-20 or below and $0.06 per square foot for air sealing in 2026, with the balance on the electric bill. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Maryland Heights dates to around the mid-1970s; the Census Bureau's 2020-2024 median year built is 1975. Of its 13,108 homes, 1% went up before 1940 and 12% in 2000 or later. It is a median for the place, not a survey of individual houses.
Code and permit facts checked September 10, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: marylandheights.com (2, 3) · basc.pnnl.gov · library.municode.com · en.wikipedia.org · bestplaces.net · ameren.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 314-291-6550 or your electric utility first.
Free assessment, measured at the hatch, with the photographs and the number in writing.
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