Insulation quotes can look wildly different for the same house. Usually that is not because one contractor is cheap and the other is greedy — it is because they are quoting different jobs. Once you know what goes into the number, it is easy to compare.
The five things that set the price
- Attic floor area. Insulation is priced by the square foot of attic floor. A 1,600 sq ft single-story Valley ranch has roughly 1,600 sq ft of attic to cover.
- Target R-value. Going to R-49 needs more material than R-30. Inland homes usually justify the extra depth; coastal homes often do not.
- Whether the old insulation stays. Clean, dry insulation can stay and be topped up. Rodent-soiled, wet or smoke-damaged material needs removal first, which is its own line item.
- Prep work. Air sealing, eave baffles, can-light covers and an insulated hatch add a little cost and a lot of performance.
- Access and material. A tall, open attic is fast. A low-slope Craftsman roof with 20 inches of clearance is slow, hand-placed work. Spray foam costs more per square foot than blown-in.
Typical ranges
These are the general ranges Los Angeles homeowners see across the market. Your written quote will be specific to your attic.
| Job | Typical range |
|---|---|
| Blown-in top-up to R-38/R-49 | $1.50–$3.25 / sq ft |
| Old insulation removal + clean-up | $1.25–$3.00 / sq ft |
| Attic air sealing | $500–$1,800 / home |
| Radiant barrier | $0.90–$1.80 / sq ft |
| Spray foam (open-cell, roof deck) | $2.50–$5.50 / sq ft |
How to compare two quotes
Put them side by side and check that each one lists the same things: square footage, target R-value, installed depth, material, whether old insulation is removed, and which prep items are included. A quote that just says "insulate attic — $2,400" leaves too much unsaid.
Also ask whether someone actually went into the attic. A quote built from your home's square footage on a listing site cannot know about rodent damage, old wiring or a missing section over the garage.
Rebates and incentives
Utility programs from LADWP, SCE, SoCalGas and the city utilities in Burbank, Glendale and Pasadena change often. We will tell you what we know is active and provide the paperwork, but always confirm eligibility directly with your utility before you count on a rebate.
