Attic Insulation cost: Denver vs Longmont (2026)
Denver runs 9% higher than Longmont for attic insulation — expect around $4,400 in Denver against $4,050 in Longmont, a difference of about $350.
Denver CO
Typically around $4,400
Longmont CO
Lower costTypically around $4,050
Denver vs Longmont: full breakdown
| Factor | Denver | Longmont |
|---|---|---|
| Typical 2026 cost | $4,400 | $4,050 |
| Estimated range | $1,750–$7,000 | $1,600–$6,500 |
| Labor index (vs US) | ×1.08 | ×1 |
| Climate zone | Cold | Cold |
| Climate factor | ×1.08 | ×1.08 |
| Local permit | None | None |
| Labor share | $2,400 | $2,250 |
| Materials/equipment | $2,000 | $1,800 |
Treat these as 2026 localized estimates for attic insulation, not quotes from a contractor.
How much should this gap actually matter?
A 9% gap is meaningful on a project this size — about $350. That's real money, but it's often within reach of off-season timing and a tighter apples-to-apples bid in Denver.
Attic insulation by type: Denver vs Longmont
Every attic insulation type gets its own localized price for each metro, using the same labor, climate and permit adjustments — a true apples-to-apples comparison.
| Type | Denver | Longmont |
|---|---|---|
| Fiberglass batts | $1,750–$4,650 | $1,600–$4,300 |
| Blown-in fiberglass | $1,750–$5,250 | $1,600–$4,850 |
| Blown cellulose | $2,000–$5,850 | $1,850–$5,400 |
| Spray foam | $4,100–$10,500 | $3,800–$9,700 |
Attic insulation numbers here are 2026 planning ranges, adjusted per city — useful for budgeting, not a substitute for an actual quote.
Attic insulation by area: Denver vs Longmont
Attic insulation is priced by the square foot of attic floor, typically $1–$7 per sq ft installed depending on material and how deep you build the R-value. Blown-in is cheapest; spray foam costs the most.
| Size | Denver | Longmont |
|---|---|---|
| 500 sq ft | $800–$2,550 | $750–$2,400 |
| 1,000 sq ft | $1,400–$4,100 | $1,300–$3,800 |
| 1,500 sq ft | $2,100–$5,850 | $1,950–$5,400 |
| 2,000+ sq ft | $2,800–$7,600 | $2,600–$7,000 |
All figures are 2026 localized planning estimates for attic insulation — get an actual quote before you commit.
What insulation pros earn in each metro
With labor making up about 55% of a attic insulation job, wage differences between metros do most of the work here. These figures are real BLS OEWS installer wages, not modeled estimates.
Denver-Aurora-Centennial metro · about 15% above the US average installer wage.
No BLS metro wage series for Longmont; we use Colorado regional price parity instead.
Source: U.S. Bureau of Labor Statistics, OEWS metro wages for HVAC installers (used as a trade-labor index).
Cheapest time for attic insulation in either city
Fall is when everyone rushes to insulate before winter hits, making it the busiest and priciest season. Spring and summer see far less demand — and utility rebate budgets are often still full that early in the year.
How much insulation is worth paying for?
Insulation is one of the few home upgrades where spending more can genuinely pay for itself. Our editors on the choices that decide both cost and payback.
The rebate case
Insulation has some of the best rebate math in home improvement — utility and state programs can cover a solid share (the federal 25C credits ended Dec 2025). Check DSIRE before you book and time it to a fresh rebate budget.
The R-value case
Aim for the R-value the DOE assigns your zone, not a round number that sounds close enough. Every point you fall short is comfort you don't feel and utility savings you never bank — savings that would have covered the extra material several times over.
The air-sealing case
Insulation without air-sealing underperforms. Sealing leaks first is cheap and often delivers more comfort per dollar than thicker insulation alone — make sure it's in the scope.
Don't half-do an insulation job to save money upfront: seal the air leaks first, insulate to the DOE target for your zone, and stack the rebates. The full scope pays back faster than the partial one.
Denver vs Longmont
Is attic insulation cheaper in Denver or Longmont?
Yes — Denver costs more. Expect around $4,400 for attic insulation there against $4,050 in Longmont, about $350 (9%) apart in 2026.
Why does attic insulation cost more in Denver than Longmont?
Labor rates explain most of it — 1.08 in Denver vs 1 in Longmont. A cold climate versus cold accounts for the rest.
How much is attic insulation in Denver, CO?
Expect to pay $1,750 to $7,000 for attic insulation in Denver in 2026, averaging around $4,400.
When is the cheapest time to buy attic insulation — and does it differ by city?
It doesn't vary by location — Spring and summer is the discount window in both Denver and Longmont (roughly 5–10% off), while the pre-winter fall rush tends to be the most expensive in either city.
Should I choose where to live based on attic insulation cost?
Rarely. The $350 difference is real but one-time, and you can often close most of it in Denver by buying in the off-season and getting tighter, apples-to-apples bids. Ongoing factors — energy prices, climate and home condition — matter more over the life of the system.
Compare attic insulation in other cities
Updated June 2026 · By Serhat Özçelik