Attic insulation, air sealing, crawl spaces and walls for homes in Glen Carbon — starting with a free assessment that measures the R-value you actually have. The typical home here dates to the early-1990s, and 5% of its 6,007 homes went up before 1940.
Glen Carbon runs to about 10 square miles and roughly 13,842 people. It sits about 14 miles northeast of downtown St. Louis. Around 6,007 housing units sit inside those boundaries. The community dates back to 1892. We cover ZIP code 62034.
No completed job in Glen Carbon is logged in our records yet, and this page will say so until one is.
The typical home in Glen Carbon dates to around the early-1990s. 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.
That includes Old Town. Housing age and construction shift across Glen Carbon, sometimes by decades within a few streets, which is why we look in the attic before quoting rather than after.
Glen Carbon's heritage museum grounds include the Yanda Log Cabin, built around 1853, one of the area's oldest structures; the village itself was founded in 1892.
The Census Bureau estimates 6,007 homes in Glen Carbon. 310 of them (5%) went up before 1940 — 22nd of 44 places on this site for pre-1940 housing. The 1990s were the busiest decade, adding 1,411 of today's homes (23%); 34% predate 1980 and 26% were built in 2000 or later. For Madison County as a whole the pre-1940 share is 15%, so Glen Carbon sits below it.
Of 5,836 occupied homes, 57% heat with utility gas and 42% with electricity. Electric heat here is more common than across the county (32%), and ranks 8th 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.
69% of occupied homes are owner-occupied and 70% of all homes are single-family detached houses. Read together, those numbers point toward an energy assessment before deciding what to fix first.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 310 | 5% | |
| 1940s | 125 | 2% | |
| 1950s | 137 | 2% | |
| 1960s | 397 | 7% | |
| 1970s | 1,088 | 18% | |
| 1980s | 952 | 16% | |
| 1990s | 1,411 | 23% | |
| 2000s | 950 | 16% | |
| 2010s | 551 | 9% | |
| 2020 or later | 86 | 1% |
6,007 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 5,836 occupied.
2,363 of Glen Carbon's 6,007 homes (39%) 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.
Glen Carbon enforces the Illinois Energy Conservation Code (2024 IECC with Illinois amendments). The Village's Current Village Building Codes page lists its adopted codes as the 2018 International Residential Code, 2018 International Building Code, 2018 International Mechanical Code, 2018 International Fuel Gas Code, 2018 International Property Maintenance Code, 2018 International Swimming Pool and Spa Code, 2018 Illinois Accessibility Code, the 2013 Village of Glen Carbon Rental Property Code and the 2017 National Electrical Code. For energy it does not name an IECC edition of its own; it lists the Illinois Energy Conservation Code, Commercial and Residential, as the applicable code, pointing to the state edition, currently the 2024 IECC as amended effective 11/30/2025.
Under that edition the required attic value for new work here is R-49, and walls R-20 + R-5 continuous, or R-13 + R-10 continuous. For comparison, the Department of Energy recommends R60 for an uninsulated attic in climate zone 4A, where Glen Carbon sits, and R49 where there are already a few inches up there.
Table R402.1.3 of the 2024 IECC as amended for Illinois, climate zone 4. Madison County is in climate zone 4 per the NAIMA IECC compliance guide for Illinois homes.
Nothing Glen Carbon publishes settles this. Its permit lists name the work types it cares about, and insulation is not among them in either direction. The Village routes permit applications through a Tyler EnerGov portal and does not publish a list of permit types on its website, so insulation is neither listed nor excluded. So we ask the department directly before the first day on site, and whatever comes back, pulling it is our job rather than yours.
No contractor registration or licensing requirement is published on the Village's building codes page or its applications and permits page.
The published number is 618-288-2615. The department page is here.
Permitting is on us, not on you.
Ameren Illinois serves most Glen Carbon addresses, and its 2026 discount table pays $1.10 per square foot for attic or wall insulation, $2.50 per linear foot for rim joist, $3.75 per linear foot for crawl space wall and $0.70 per cubic foot per minute (CFM) of air leakage reduced for air sealing, taken off the invoice. The discount comes off a registered Ameren Illinois Program Ally's price, once the program's home energy assessment confirms the house is eligible. Income-qualified households can apply to Madison County Community Development (618-692-8940) for free weatherization instead. The full program rules are on the Madison County page and in the rebate guide.
Every layer of an insulated attic, explained
Glen Carbon borders Edwardsville, Troy, Maryville and Pontoon Beach. These are the ones we also cover, each with its own energy code and permit rule:
Elsewhere in Madison County we also cover:
Illinois sets the residential energy code from Springfield, so the attic figure is R-49 wherever it is published here; what changes is the permit desk, and none of the 5 publishes a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Glen Carbon | Illinois state code | R-49 | Not published | 618-288-2615 |
| Edwardsville | Illinois state code | R-49 | Not published | 618-692-7535 |
| Alton | Illinois state code | R-49 | Not published | 618-463-3500 |
| Collinsville | Illinois state code | R-49 | Not published | 618-346-5200 |
| Granite City | Illinois state code | R-49 | Not published | 618-452-6218 |
All 5 Madison County jurisdictions side by side →
Glen Carbon enforces the Illinois state code, which sets R-49 for an attic in new work. That code also reaches work on existing houses, not only new ones.
Not on paper: Glen Carbon names neither a permit nor an exemption for insulation, so one call to the department at 618-288-2615 settles it first.
Ameren Illinois publishes $1.10 per square foot for attic insulation and $0.70 per cubic foot per minute (CFM) of air leakage reduced for air sealing for 2026; only a registered Program Ally can apply it, once an assessment shows the house qualifies. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Glen Carbon dates to around the early-1990s; the Census Bureau's 2020-2024 median year built is 1990. Of its 6,007 homes, 5% went up before 1940 and 26% 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: glencarbonil.gov (2, 3, 4) · codelibrary.amlegal.com · en.wikipedia.org · bestplaces.net · ameren.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 618-288-2615 or your electric utility first.
Free assessment, a measured R-value, and photos you keep either way.
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