Attic insulation, air sealing, crawl spaces and walls for homes in Columbia — starting with a free assessment that measures the R-value you actually have. The typical home here dates to the early-1990s, and 8% of its 4,735 homes went up before 1940.
Columbia runs to about 11 square miles and roughly 11,127 people. It sits about 20 miles south of downtown St. Louis. Around 4,735 housing units sit inside those boundaries. The community dates back to 1859. We cover ZIP code 62236.
No completed job in Columbia is logged in our records yet, and this page will say so until one is.
The typical home in Columbia 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.
A relatively young housing stock, with the largest single decade of construction (about 20%) in the 2000s.
First incorporated in 1859 as a small farming settlement on the Mississippi River bluffs, Columbia has grown steadily as suburban development pushes south from St. Louis; Columbia and Waterloo are expected to grow toward each other's borders.
The Census Bureau estimates 4,735 homes in Columbia. 368 of them (8%) went up before 1940 — 18th of 44 places on this site for pre-1940 housing. The 2000s were the busiest decade, adding 958 of today's homes (20%); 37% predate 1980 and 35% were built in 2000 or later. For Monroe County as a whole the pre-1940 share is 10%, so Columbia sits below it.
Of 4,448 occupied homes, 56% heat with utility gas and 41% with electricity; another 2% burn propane or other tank gas. Electric heat here is more common than across the county (30%), and ranks 9th 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.
82% of occupied homes are owner-occupied and 81% of all homes are single-family detached houses. Read together, those numbers point toward air sealing on newer houses that already have depth and an energy assessment before deciding what to fix first.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 368 | 8% | |
| 1940s | 154 | 3% | |
| 1950s | 318 | 7% | |
| 1960s | 566 | 12% | |
| 1970s | 342 | 7% | |
| 1980s | 568 | 12% | |
| 1990s | 766 | 16% | |
| 2000s | 958 | 20% | |
| 2010s | 624 | 13% | |
| 2020 or later | 71 | 1% |
4,735 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 4,448 occupied.
1,334 of Columbia's 4,735 homes (28%) 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.
Columbia enforces the Illinois Energy Conservation Code (2024 IECC with Illinois amendments), by state law. The Illinois Energy Conservation Code governs residential energy work by statute.
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 Columbia 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. Monroe County is in climate zone 4 per the NAIMA IECC compliance guide for Illinois homes.
Nothing Columbia publishes settles this. Its permit lists name the work types it cares about, and insulation is not among them in either direction. The city's published permit categories are residential and commercial building permits, sign permits and occupancy permits. Insulation is not named as a permit type. So we ask the department directly before the first day on site, and whatever comes back, pulling it is our job rather than yours.
The city issues an Electrician Registration license and publishes a Registered Electrical Contractor List, but publishes no registration requirement for general or insulation contractors.
The published number is 618-281-7144. The department page is here.
Permitting is on us, not on you.
Ameren Illinois serves most Columbia 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 Western Egyptian Economic Opportunity Council (serves Monroe, Perry and Randolph counties) (618-965-3458) for free weatherization instead. The Monroe County page and the rebate guide carry the full rules.
Every layer of an insulated attic, explained
Columbia borders Dupo, Millstadt and Waterloo. These are the ones we also cover, each with its own energy code and permit rule:
Also on this site, in neighboring St. Clair County:
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 neither publishes a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Columbia | Illinois state code | R-49 | Not published | 618-281-7144 |
| Waterloo | Illinois state code | R-49 | Not published | 618-939-8600 |
Both Monroe County jurisdictions side by side →
Columbia 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: Columbia names neither a permit nor an exemption for insulation, so one call to the department at 618-281-7144 settles it first.
Ameren Illinois' 2026 table: $1.10 per square foot for attic insulation and $0.70 per cubic foot per minute (CFM) of air leakage reduced for air sealing, taken off the invoice by a registered Program Ally following a home energy assessment. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Columbia dates to around the early-1990s; the Census Bureau's 2020-2024 median year built is 1991. Of its 4,735 homes, 8% went up before 1940 and 35% 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: columbiail.gov (2, 3) · 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 618-281-7144 or your electric utility first.
Free assessment, a measured R-value, and photos you keep either way.
Book my free assessment →