Short answer
Published Bay Area market ranges put blown-in attic insulation at $1.20 to $4.50 per square foot installed, or roughly $1,200 to $6,750 for a 1,000–1,500 sq ft attic. Removing old insulation, air sealing and rodent work are priced on top. These are market ranges as of October 14, 2026, not Attic WISE prices.
Prices up front, fine print included.
Work priced by the square foot, on one scale. Each band runs from the lowest to the highest published Bay Area figure, as of October 14, 2026.
Installed price per sq ft
Fifteen kinds of attic and envelope work, in the same groups as our services. Each service name links to what the job involves.
Bay Area market range · collected October 14, 2026 · not an Attic WISE price list
Keep the heat where you paid for it.
| Service | Market range | Typical job | Sources |
|---|---|---|---|
| Blown-in insulation | $1.20–$4.50per sq ft of attic floor, installed | $1,200–$6,7501,000–1,500 sq ft attic | [1][2][3][4] |
| Batt insulation | $0.50–$2.00per sq ft covered, installed | $700–$3,200800–1,500 sq ft attic floor in fiberglass batts | [5][2] |
| Spray foam insulation | $1.50–$7.00per sq ft sprayed, installed | $1,500–$7,0001,000 sq ft of sprayed surface | [2][6][7] |
| Variant: Open-cell foam | $1.50–$3.50/sq ft | [2][7] | |
| Variant: Closed-cell foam | $3.00–$6.50/sq ft | [2][7] | |
| Radiant barrierThin data | $0.90–$3.00per sq ft of attic, installed | $900–$2,0001,000 sq ft attic, foil radiant barrier | [8] |
| Variant: Foil radiant barrier | $0.90–$2.00/sq ft | [8] | |
| Variant: Spray-on radiant barrier | $1.90–$3.00/sq ft | [8] | |
| Existing-wall insulationThin data | $1.50–$3.00per sq ft of exterior wall, installed (blown into closed walls) | $1,500–$4,500Exterior walls of a typical Bay Area house | [6] |
| Garage ceiling insulationMixed dataThin data | $0.50–$4.50per sq ft of garage ceiling, installed | $250–$2,6002-car garage ceiling, about 576 sq ft | [9][5][2][3] |
| Crawl space & underfloor insulationThin data | $1.50–$3.50per sq ft of crawl space, batts between floor joists + ground vapor barrier, installed | $1,500–$3,5001,000 sq ft crawl space | [7] |
| Variant: Floor-joist batts, no vapor barrier | $1.00–$2.00/sq ft | [7] | |
| Variant: Closed-cell spray foam | $3.00–$6.50/sq ft | [7] | |
| Variant: Ground vapor barrier only | $0.50–$1.50/sq ft | [7] | |
| SoundproofingThin data | $400–$2,050per job, acoustic insulation in interior walls or ceilings | Insulation only, in walls or ceilings that are open or can be filled; no drywall rebuild | [10][5] |
Get the old stuff, and whatever moved in, out.
| Service | Market range | Typical job | Sources |
|---|---|---|---|
| Attic cleaning & sanitizing | $1,500–$4,500per job, cleaning and sanitizing after rodents | One attic, cleaned and sanitized after rodents | [3][11] |
| Variant: Cleaning and sanitizing after rodents | $1,500–$4,500/job | [3][11] | |
| Variant: Basic attic cleaning, no contamination | $500–$1,500/job | [3] | |
| Insulation removal & replacement | $1.00–$3.00per sq ft of attic floor, removal and disposal | $1,000–$4,5001,000–1,500 sq ft attic, removal only | [2][5][4] |
| Variant: Cleaning and sanitizing after rodents | $1,500–$4,500/job | [3][11] | |
| Variant: Basic attic cleaning, no contamination | $500–$1,500/job | [3] | |
| Variant: Full restoration: remove, clean, sanitize, seal, re-insulate | $4,000–$12,000/job | [3] | |
| Rodent proofing | $250–$6,000per job, sealing entry points | $600–$2,000Attic-level entry points sealed after the inspection | [3][12][11] |
| Variant: A few holes (1–3 entry points) | $250–$800/job | [12][11] | |
| Variant: Attic entry points | $600–$2,000/job | [3][12] | |
| Variant: Whole-home exclusion (roof, vents, foundation) | $2,500–$6,000/job | [11] | |
| Ember-resistant ventsN. California data | $53–$421per vent, replaced and installed | $450–$3,5006–14 vents | [13] |
| Variant: Eave or soffit vent | $105–$106/vent | [13] | |
| Variant: Gable-end vent | $421/vent | [13] | |
| Variant: Circular vent in open-eave blocking | $53/vent | [13] |
Stop the leaks, then let the attic breathe.
| Service | Market range | Typical job | Sources |
|---|---|---|---|
| Air sealingThin data | $500–$1,500per job, attic floor air sealing | Done alongside attic insulation work | [4] |
| Ductwork sealing & replacementThin data | $500–$12,100per job | Depends on the work: see the rows below. | [14] |
| Variant: Partial repair or extension | $500–$1,400/job | [14] | |
| Variant: Seal existing ducts | $1,200–$2,500/job | [14] | |
| Variant: Replace the duct system (1,500–2,000 sq ft home) | $4,800–$12,100/job | [14] | |
| Attic ventilation & fansNational data onlyThin data | $150–$1,400per vent or fan, installed | $150–$1,400One added vent or attic fan | [15] |
| Variant: Add a roof or gable vent, or an attic fan | $150–$1,400each | [15] | |
| Variant: Soffit baffles, whole attic | $320–$880/job | [4] | |
| Variant: Whole-house fan | $600–$2,300each | [16] |
Thin data means one source, older figures or a scope borrowed from similar work. Treat those ranges as a rough guide.
The same arithmetic the estimator uses, run on three common situations. Every line comes from the ranges above.
A single-story house with about 1,200 sq ft of attic floor. The old insulation is clean but has slumped to a few inches. Seal the leaks, then blow new insulation over the top.
About 1,500 sq ft of attic floor under decades-old insulation, gray with dust and packed down where people have walked. It all comes out before anything new goes in.
About 1,000 sq ft of attic floor, with droppings in the insulation and a gap at the eaves. Soiled insulation comes out, the attic is cleaned and sanitized, the entry points are closed, then it's re-insulated.
| Line | How it's figured | Range |
|---|---|---|
| Remove old insulation | 1,000 sq ft × $1.00–$3.00/sq ft | $1,000–$3,000[2][5][4] |
| Clean and sanitize the attic | One job | $1,500–$4,500[3][11] |
| New attic insulation | 1,000 sq ft × $1.20–$4.50/sq ft | $1,200–$4,500[1][2][3][4] |
| Air sealing | One job | $500–$1,500[4] |
| Rodent proofing | One job | $600–$2,000[3][12] |
$4,800–$15,500
Adding every line's high end overstates the top: few jobs hit the high end of every line at once. The low end assumes easy access and a straightforward attic.
Two attics on the same street can land at opposite ends of a range. Here is what pushes a Bay Area attic job up or down, and what to look for before anyone climbs through your hatch.
Most insulation work is priced per square foot of attic floor, which roughly matches the footprint of the rooms below. A two-story house has a smaller attic than a one-story house with the same living space, because only the top floor has attic above it. Then there's access. A low roof pitch, a tight hatch in a closet ceiling, or an attic crowded with ducts and framing takes longer to work in, and that time shows up in the labor.
California's 2025 Energy Code treats adding or replacing attic insulation as an "altered ceiling". Depending on your climate zone and on what's up there now, that usually means R-49 at the ceiling, sometimes with air sealing, recessed-light covers and a ventilation check on the same job, and attics already at R-38 or more are exempt. The zone-by-zone rules are on our Title 24 attic insulation page.
R-49 is a lot of material, and going from a few slumped inches to that depth is most of what a blown-in quote pays for. So a good quote states both the R-value and the depth in inches, and you can check the depth with a ruler after install day.
If the old insulation is clean and dry, the new layer can usually go on top of it. If it's packed down, damp, moldy or soiled, it comes out first, and removal is priced per square foot on top of the new insulation. A bare attic floor is also the easiest time to air seal, because every gap is in plain sight.
Droppings change the job. California's public health department says never to sweep or vacuum them, because of hantavirus (are rodent droppings dangerous? has its guidance), and that care takes time and materials, so Bay Area price lists show cleaning and sanitizing as its own job, separate from removal. Closing the gaps the animals used is a third line, rodent proofing, and it's what keeps the new insulation clean.
Several smaller jobs are easiest while the attic is open: sealing top plates, wire holes and the hatch before new insulation buries them; covers over recessed lights; baffles at the eaves so air keeps moving (attic ventilation); and sealing leaky duct joints (ductwork). Each one is a separate line in the market ranges above, so a quote that bundles them should still list them.
Summer is the busy season for attic work, and some Bay Area contractors publish higher prices for July than for October. Some companies also set a minimum job charge, so a small attic doesn't always cost proportionally less than a big one.
Two finds stop an attic job until a specialist has looked. Knob-and-tube wiring: the electrical code allows insulation over it only after an electrical contractor surveys the wiring and puts its condition in writing, and Berkeley asks for that report before inspection (knob-and-tube guide). Vermiculite: the EPA says to assume vermiculite attic insulation contains asbestos and not to disturb it (vermiculite guide). In either case Attic WISE refers you to the right specialist and doesn't do that part of the work. Their fees aren't in the ranges on this page.
Almost every range on this page comes from prices published for the Bay Area, collected on the date shown and cited row by row. The exceptions are marked in the table.
The worked examples use the same arithmetic as the estimator: attic size times the per-square-foot range for each line, plus the one-job ranges for the rest. Lows and highs are added separately, then rounded outward to the nearest fifty dollars.
Whoever you hire, a written quote should let you check the work afterward. Look for:
The Contractors State License Board's advice for any home-improvement job is short: don't let payments get ahead of the work. Then hold the total up against the ranges on this page. A quote far above the envelope deserves a question. One far below it deserves two.
California caps the deposit on a home-improvement contract. Attic WISE takes one only after you sign, and never more than the cap.
Deposit cap
10% of the contract price or $1,000, whichever is less
| Contract price | Largest deposit allowed |
|---|---|
| $2,500 | $250 |
| $6,000 | $600 |
| $10,000 | $1,000 |
| $18,000 | $1,000 |
The inspection itself is free. Rather skip the visit? Send photos or video for an estimate instead.
Status checked October 23, 2026
Plenty of insulation pages still advertise money that's gone. Here's where each program in our cities stands, status only; amounts and conditions are on the rebates page.
The federal 25C credit doesn't cover insulation or air sealing placed in service after December 31, 2025. What that means for your project
Status only. Amounts and conditions are on the rebates page.
Bottom line
For most Bay Area homeowners in 2026 there's no cash incentive for attic insulation on its own, so plan with the ranges above as they stand.
Amounts, conditions and official pages: Bay Area attic insulation rebates
Bay Area contractors and cost guides publish $1.20 to $4.50 per square foot for blown-in attic insulation, installed. For a 1,000–1,500 sq ft attic, that's roughly $1,200 to $6,750. Removing old insulation, air sealing and rodent work are priced on top. These are market ranges as of October 14, 2026, not Attic WISE prices.
Published Bay Area figures for removal and disposal run $1.00 to $3.00 per square foot of attic floor. When rodents have been in the attic, cleaning and sanitizing is usually its own job, at $1,500 to $4,500. A full restoration (remove, clean, sanitize, seal and re-insulate) is published at $4,000 to $12,000.
The ranges overlap: batts run $0.50 to $2.00 per square foot and blown-in $1.20 to $4.50 in published Bay Area figures. Batts take longer to cut and fit around wiring, ducts and framing, so cheaper material doesn't always mean a cheaper job. The inspection decides which suits your attic.
One Bay Area figure puts attic air sealing at $500 to $1,500 when it's done along with insulation. Under California's 2025 Energy Code, an attic in climate zone 2, 4 or 12 with less than R-19 must be air sealed when insulation is added, unless an exception applies, so it often isn't optional.
Northern California unit costs run from about $53 for a small circular eave vent to about $421 for a gable-end vent, installed. For a house with 6–14 vents, California installed prices come to roughly $450 to $3,500. Vent count and type set the total.
Each range is an envelope: the lowest low and the highest high that Bay Area sources publish for the same work. One source may be pricing a clean attic with easy access, another a rodent-damaged one behind a closet hatch. Your attic sits somewhere inside the range, and the inspection finds where.
The ranges are before any incentive; our rebates page tracks which Bay Area programs are open, and the insulation tax credit page explains the federal side.
On a home-improvement contract, no more than 10% of the contract price or $1,000, whichever is less. Attic WISE takes a deposit only after you sign, and never more than that cap.
California law gives three business days, or five if you're 65 or older. Attic WISE gives every customer five business days.
No. The in-home inspection is free, and photos or video can stand in for the visit.
Attic WISE hasn't published a price list yet. Until it does, this page shows what the Bay Area market publishes, with sources and dates, so you can judge any quote you get, ours included.
Numbers match the [n] marks in the tables. Each page was read in full on the date shown; figures copied from a national guide by a local page were set aside.
Published by: Attic WISEUpdated:
A few questions give you a Bay Area market range for your attic's size and condition. A free inspection, or photos and video if you'd rather skip the visit, turns that range into a written quote.
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Before any work starts