Cost to Wall Insulation (Blown-In) in St. Louis, MO (2026)
If you’re budgeting a wall insulation (blown-in) in St. Louis, most projects run $1,010-$5,049, 1% above the $2,500 national average. What moves that number most is usually one thing: Wall Area (Square Feet). On its own it can swing the cost by $500 - $4,000, so that’s the decision to slow down on before you sweat the smaller stuff.
Easiest place to save: The IRA 30% Energy Efficient Home Improvement Credit covers blown-in wall insulation costs up to $1,200 per year. Combine this with utility rebates to cut your net cost by 40-60%.
In the Midwest (where St. Louis sits): Cold winters create excellent ROI for wall insulation - heating savings of $150-$350/year are common in previously uninsulated homes. Labor costs are near the low end of the national range. Many Midwest utilities offer rebates for wall insulation through their energy efficiency programs.
$1,010-$5,049 in St. Louis
1% above the national average · 1.01x cost multiplier
In St. Louis, a wall insulation (blown-in) runs $1,010 to $5,049 on average - about 1% above what homeowners pay nationwide. The Midwest market's labor costs account for most of the gap, with material pricing and local permitting fees adding to the spread. Use the cost table below to compare budget, mid-range, and premium options side by side.
Cost Breakdown in St. Louis
| Line Item | Low | Mid | High |
|---|---|---|---|
| Cost per sq ft | $1 | $2 | $4 |
| Materials | $376 | $846 | $1,880 |
| Labor | $840 | $1,890 | $3,674 |
| Permits | $0 | $0 | $188 |
| Total | $1,216+1% vs. national avg | $2,736+1% vs. national avg | $5,742+1% vs. national avg |
Budget
Blown-in cellulose, 1,000 sq ft of exterior wall, drill-and-fill method, patch holes
Mid-Range
Dense-pack cellulose or fiberglass, 2,000 sq ft, existing home retrofit with patching
Premium
Spray foam or high-performance dense-pack, full exterior envelope, older home
Material Options
Material prices below are national averages; availability in St. Louis may shift costs slightly.
| Material | Cost/Unit | Best For |
|---|---|---|
| Blown-In Cellulose (Standard) | $1.00 - $2.00 per sq ft installed | Most retrofits - the default choice for drill-and-fill wall insulationRecycled content, excellent air-sealing properties, R-3.5/inch, fire-treated, widely available |
| Blown-In Fiberglass (Standard) | $1.00 - $2.00 per sq ft installed | Humid climates where moisture management is a concernDoes not settle, moisture-resistant, R-2.2-2.7/inch, lighter than cellulose |
| Dense-Pack Cellulose | $1.50 - $2.50 per sq ft installed | Exterior walls where settling would reduce performance, high-performance retrofitsHigher density (3.5 lbs/cubic ft) virtually eliminates settling, better air sealing than standard blown-in |
| Open-Cell Spray Foam (R-3.7/inch) | $2.00 - $3.50 per sq ft installed | New construction or gut renovations where walls are already openExcellent air sealing, fills irregular cavities completely, soft and flexible |
| Closed-Cell Spray Foam (R-6.5/inch) | $3.00 - $5.00 per sq ft installed | New construction, below-grade walls, extremely cold climates needing maximum R-valueHighest R-value per inch, acts as vapor barrier, rigid structural improvement |
Other Projects in St. Louis
St. Louis Estimate
Typical Range
$1,010-$5,049
vs. National Average
1% above national
Cost Multiplier
1.01x
Cost Per sq ft
$1-$4
This 1.01x estimate prices St. Louis labor from BLS Occupational Employment and Wage Statistics (May 2025) and applies a lighter regional adjustment to materials and permits, which vary less by metro than labor does. Actual bids vary by contractor, project scope, and timing.
See national average costs →