Attic insulation in St. Louis
St. Louis has some of the oldest housing in the country: the city's median home was built in 1938, and 58% of homes predate 1940.1 Old attics often mean thin insulation, air leaks and sometimes vermiculite, so the attic is the place to start.
Housing age
86% of St. Louis city homes were built before 1980, versus about half nationally.1
Electric rebate
Ameren Missouri's 2026 PAYS program lists $0.20 per sq ft for attic insulation to R-38.2
Heating
67% of city homes heat with utility gas and 31% with electricity.1
Start by looking (carefully) at what's there
Vermiculite from a mine near Libby, Montana, made up over 70% of the vermiculite sold in the U.S. from 1919 to 1990, and it was contaminated with asbestos.3 Most St. Louis homes were built within that window.1 That doesn't mean your attic has it, but it's worth a look before anyone starts work.
Rebates in St. Louis
Ameren Missouri: Pay As You Save (PAYS)
- Ceiling/attic insulation: $0.20 per sq ft, for blown-in cellulose to at least R-38 in an attic that starts at R-20 or below.2
- Air sealing: $0.06 per sq ft, if a 20% leakage reduction is achievable.2
- You must participate in tier 4 of PAYS and have lived in the home for the past 12 months. Valid January 1 to December 31, 2026.2
Spire (natural gas)
Spire's Missouri tariff, filed with the Missouri Public Service Commission and effective October 24, 2025, lists an insulation rebate of $0.40 per sq ft, up to $750, for reaching at least R-38.4 Spire's mail-in form adds the details: attic/ceiling or floor insulation, existing homes only (no new builds), with proof of purchase and installation.5 Funding and terms can change, so confirm with Spire before you count on it.
Worked numbers are on the St. Louis cost page.
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If the old insulation is ordinary fiberglass or cellulose that's damaged by water, pests or fire, removal costs $1 to $2 per square foot nationally, and replacement $2 to $6 including removal.6 If it's vermiculite, it's an asbestos job first, then an insulation job.3
Choosing an attic insulation contractor in St. Louis
- Ask whether they participate in Ameren's PAYS program if you want that rebate.2
- Ask what they'll do if they find vermiculite. The right answer is to stop and bring in an asbestos professional.3
- Get the starting and ending R-values in writing: the Ameren and Spire rebates both depend on reaching R-38.24
Areas we serve
We match homeowners across the St. Louis area, including these communities and ZIP codes:
- St. Louis (city)63101 · 63102 · 63103 · 63104 · 63106 · 63107 · 63108 · 63109 · 63110 · 63111 · 63112 · 63113 · 63115 · 63116 · 63118 · 63120 · 63139 · 63143 · 63147 · 63155
- University City63130
- Clayton63105
- Maplewood63143
- Webster Groves63119
- Kirkwood63122
- Brentwood63144
- Ladue63124
- Creve Coeur63141
- Maryland Heights63043 · 63146
- Chesterfield63005 · 63017
- Ballwin63011 · 63021
- Florissant63031 · 63033
- St. Charles63301 · 63303
- St. Peters63376
- O'Fallon, MO63366 · 63368
- Belleville, IL62220 · 62226
- Edwardsville, IL62025 · 62026
ZIP codes are 2020 Census ZIP Code Tabulation Areas, which closely approximate USPS ZIP codes. We list ZIPs that make up a substantial share of each community, so edge ZIPs that barely touch a town are left out, and some ZIPs span two towns.7 Not on the list? Send the form anyway, and we'll tell you if we can help.
Common questions
Does Ameren Missouri offer an attic insulation rebate in 2026?
Yes, through the Pay As You Save program: $0.20 per square foot for blown-in cellulose to at least R-38 from R-20 or below, for tier 4 PAYS participants who've lived in the home 12 months.
Does Spire offer an insulation rebate?
Spire's Missouri tariff, effective October 24, 2025, lists $0.40 per square foot, up to $750, for insulation to at least R-38 in an existing home. Confirm with Spire before you count on it.
Could my St. Louis attic have vermiculite?
It's possible in older homes. The EPA says to assume vermiculite insulation contains asbestos and leave it undisturbed.
Can I stack Ameren and Spire rebates?
They're separate utility programs with their own rules. Ask both utilities, or a contractor who participates in both, before you plan on combining them.
General information summarized from the public sources listed below. It isn't professional, engineering or legal advice. Codes and programs change; confirm current requirements with your local building department or utility before you start.
Sources
- U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, tables B25035 (median year built), B25034 (year built), B25003 (tenure), B25040 (house heating fuel)
- Ameren Missouri, "Pay As You Save Program" rebate sheet, valid Jan. 1–Dec. 31, 2026 (PDF)
- U.S. EPA, "Protect Your Family from Asbestos-Contaminated Vermiculite Insulation"
- Spire Missouri tariff P.S.C. MO. No. 9, sheet R-30, Residential High Efficiency Rebate Program (issued Sept. 24, 2025; effective Oct. 24, 2025; Missouri PSC EFIS, PDF)
- Spire, Missouri residential rebate mail-in form (newest version we found on Spire's site, dated Oct. 2025, PDF)
- HomeGuide, "Attic Insulation Cost" (national figures, Jan. 13, 2026)
- U.S. Census Bureau, 2020 ZIP Code Tabulation Area relationship files