Insulation and air sealing for Granite City homes: attics, crawl spaces, rim joists and walls, starting with a free assessment of the R-value you actually have. The typical home here dates to the late-1950s, and 23% of its 12,854 homes went up before 1940.
Granite City runs to about 21 square miles and roughly 27,549 people. It sits about 6 miles north of downtown St. Louis. That is roughly 12,854 housing units. The community dates back to 1896. We cover ZIP code 62040.
Our job history shows nothing in Granite City so far. Plenty of sites will show you a number here anyway.
The typical home in Granite City dates to around the late-1950s. 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.
Housing includes an early-1900s steel-industry-era layer in neighborhoods like Wilson Park ("turn-of-the-20th-century" homes) and Lincoln Place (first populated around 1906 by immigrant steelworkers, once called "Hungary Hollow"), plus later 20th-century construction.
We work across Granite City rather than one corner of it — Downtown, East Granite, West Granite, North Granite, Nameoki Strip, Bellemore, Wilson Park, Lincoln Place and Granite Park included. Construction and vintage change between them, sometimes by thirty years and a whole different framing method, which decides whether a wall can be dense-packed at all.
A "massive flood" in 1903 covered all of West Granite while the rest of the city stayed relatively dry; the city was protected from the 1993 Great Flood by its levee system.
The Census Bureau estimates 12,854 homes in Granite City. 2,978 of them (23%) went up before 1940 — 8th of 44 places on this site for pre-1940 housing. The 1950s were the busiest decade, adding 3,151 of today's homes (25%); 84% predate 1980 and 8% were built in 2000 or later. For Madison County as a whole the pre-1940 share is 15%, so Granite City sits above it.
Of 11,562 occupied homes, 70% heat with utility gas and 28% with electricity. Electric heat here is less common than across the county (32%), and ranks 30th of 44 on this site. Whoever comes out will ask about the furnace or heat pump first, since the heating fuel and the utility named on the bill settle which program money is on the table.
73% of occupied homes are owner-occupied and 81% of all homes are single-family detached houses, with 54 mobile homes in the count. On a housing mix like this, the likely starting points are an attic top-up over postwar fiberglass and an energy assessment before deciding what to fix first.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 2,978 | 23% | |
| 1940s | 1,099 | 9% | |
| 1950s | 3,151 | 25% | |
| 1960s | 2,426 | 19% | |
| 1970s | 1,175 | 9% | |
| 1980s | 494 | 4% | |
| 1990s | 477 | 4% | |
| 2000s | 751 | 6% | |
| 2010s | 278 | 2% | |
| 2020 or later | 25 | 0% |
12,854 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 11,562 occupied.
6,752 of Granite City's 12,854 homes (53%) 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.
Granite City enforces the Illinois Energy Conservation Code (2024 IECC with Illinois amendments), by state law. The city's building inspection page says Granite City adopted the International Building Code by ordinance in 2005. The Illinois Energy Conservation Code governs residential energy work by statute.
For new work, the attic number under that edition is R-49, with walls at R-20 + R-5 continuous, or R-13 + R-10 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 R402.1.3 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.
There is no published answer for Granite City. Neither the permit-required list nor the exemption list mentions insulation or air sealing at all. Insulation does not appear in the city's list of permits and applications. The city's page refers generally to permits for home improvement projects but does not name insulation as a permit type. That silence is not permission and it is not a prohibition. We settle it with a phone call before the crew is scheduled.
The published number is 618-452-6218. The department page is here.
Permitting is on us, not on you.
Ameren Illinois serves most Granite City 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 Madison County page and the rebate guide carry the full rules.
Every layer of an insulated attic, explained
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. |
|---|---|---|---|---|
| Granite City | Illinois state code | R-49 | Not published | 618-452-6218 |
| Alton | Illinois state code | R-49 | Not published | 618-463-3500 |
| Collinsville | Illinois state code | R-49 | Not published | 618-346-5200 |
| Edwardsville | Illinois state code | R-49 | Not published | 618-692-7535 |
| Glen Carbon | Illinois state code | R-49 | Not published | 618-288-2615 |
All 5 Madison County jurisdictions side by side →
Granite City 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.
Granite City has not published a rule for it; the building department at 618-452-6218 is called before the job starts.
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 Granite City dates to around the late-1950s; the Census Bureau's 2020-2024 median year built is 1957. Of its 12,854 homes, 23% went up before 1940 and 8% 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: granitecity.illinois.gov (2, 3) · library.municode.com · en.wikipedia.org (2) · ameren.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 618-452-6218 or your electric utility first.
Free assessment, measured at the hatch, with the photographs and the number in writing.
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