How Much Does Insulation Cost in San Francisco?
Attic insulation in San Francisco typically costs between $1,800 and $4,200 for a standard 1,200 to 1,800 square foot home, with most homeowners paying around $2,900 for blown-in fiberglass or cellulose. The final number depends on your attic’s current R-value, square footage, access difficulty, and whether air sealing is included. For smaller jobs like topping off existing insulation, expect to pay $1,200 to $2,000.
San Francisco’s fog belt weather pattern means your attic does real work year-round. Unlike Sacramento, where summer heat drives insulation decisions, San Francisco homeowners deal with moisture, marine air, and temperature swings between neighborhoods like the Sunset, where July highs can sit in the low 60s, and the Mission, where the same day hits the mid-70s. The right insulation, installed correctly, keeps that differential from turning into a heating bill problem.
Bryce Holloway leads Alden Insulation San Francisco, part of the Garrison Partners family since 2002. We give you a written price before any work starts, and every job carries the 365-Day Done Right Promise in writing. If the work fails within a year, we return at no charge. No exceptions, no fine print.
Insulation Cost Breakdown (2026)
Here are the numbers for the San Francisco market as of 2026. These ranges reflect what we see in homes across the Richmond, Sunset, Noe Valley, Bernal Heights, and Excelsior neighborhoods. Prices assume standard attic access and no major structural surprises.
| Insulation Service | Typical Cost Range (San Francisco) | What’s Included |
|---|---|---|
| Blown-in fiberglass (attic, R-38) | $1,800 – $3,200 | Full attic coverage, 1,200 – 1,800 sq ft, standard batt removal not required |
| Blown-in cellulose (attic, R-38) | $2,000 – $3,600 | Includes dense-pack coverage; slightly higher cost due to material handling |
| Spray foam (open-cell, attic ceiling) | $4,500 – $9,500 | Air-sealing properties included; higher material cost per board foot |
| Spray foam (closed-cell, rim joists) | $2,800 – $5,000 | Rim joist band only, typical for older SF homes |
| Attic insulation removal | $1,500 – $3,000 | Old insulation extraction, disposal, and prep for new install |
| Air sealing (attic floor) | $600 – $1,400 | Caulking, foam sealing around penetrations, top plates, duct chases |
| Insulation top-off (add R-19 to existing) | $1,200 – $2,000 | Blown-in over existing insulation, no removal needed |
San Francisco’s housing stock skews older. The median home in this city was built in 1947, which means many attics still have original mineral wool, vermiculite, or a thin layer of fiberglass batts that’s long since compressed below usefulness. In neighborhoods like Ingleside, Outer Sunset, and Portola, we regularly open attics with R-11 or worse, when the Department of Energy recommends R-30 to R-38 for this climate zone.
Every Alden Insulation San Francisco quote includes a written breakdown of materials, labor, and the specific R-value we’ll deliver. The number you approve is the number on the invoice. We install products from Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and GreenFiber, so you can look up the materials yourself before you say yes.
What Affects Insulation Pricing in San Francisco
- Current R-value in the attic. If your attic has R-11 and you want R-38, that’s a full install. If you already have R-19 and need a top-off, you’re paying for less material and less labor. The condition of what’s up there matters as much as what’s missing.
- Square footage of the attic floor. A 900 square foot attic in a Glen Park bungalow costs less than a 1,900 square foot attic in a St. Francis Wood home. Material volume and labor-hours scale directly with floor area.
- Access difficulty. Many San Francisco homes have narrow scuttle holes, steep pull-down stairs, or attics split into awkward knee-wall sections. If a technician has to maneuver material through a 22-inch opening, the labor time goes up. Homes in the Marina and Russian Hill, with their tight stairwells and flat-roof configurations, frequently present access challenges that a suburban ranch never would.
- Old insulation removal. If your attic contains vermiculite, rodent-damaged insulation, or material that’s been wet from a roof leak, removal costs $1,500 to $3,000 before new insulation goes in. This is a separate line item on our written quote, never a surprise add-on.
- Air sealing scope. The difference between an insulated attic and an efficient attic is how well the attic floor is sealed. Plumbing vents, electrical boxes, recessed light housings, and chimney chases all leak conditioned air. We quote air sealing separately because it requires different labor and materials, but it’s almost always worth doing at the same time.
- Material type. Fiberglass batts, blown-in fiberglass, cellulose, open-cell spray foam, and closed-cell spray foam are all installed in San Francisco homes, but the material prices differ significantly. Closed-cell foam costs roughly triple what blown-in fiberglass does per square foot of coverage.
San Francisco Specific Factors: Climate, Codes, and Pest Pressure
San Francisco sits in California Climate Zone 3, which the California Energy Commission defines by its marine-influenced, low-heating-degree-day profile. The building energy code, Title 24, requires R-30 minimum in attics for new construction and major renovations. For existing homes without a permit-triggering remodel, there’s no mandate forcing you to upgrade, but the utility savings alone usually justify the work.
The city’s fog belt creates a condensation issue that drier inland climates don’t face. When warm interior air leaks into a cold attic in a fog-bound neighborhood like the Outer Richmond, it condenses on the underside of the roof sheathing. Over time, that moisture can cause mold, rot, and sheathing deterioration. Proper air sealing plus the correct R-value fixes the root cause. We see this pattern in roughly one out of every three homes we inspect west of Twin Peaks.
Rodent pressure is another San Francisco reality. Rats and mice are active in nearly every neighborhood, and attics provide nesting material from old insulation. Homes in the Mission, Bernal Heights, and the Excelsior report notably high rodent activity. When we do an insulation removal, we’re often removing material that’s been contaminated. That’s an argument for removal and replacement rather than simply topping off.
How to Save on Insulation in San Francisco
The biggest lever on cost is scope. If your attic has viable existing insulation that’s just thin, a top-off costs $1,200 to $2,000 instead of a full replacement at $3,000 to $4,200. But if the existing material is compressed, water-damaged, or rodent-soiled, topping off over it is throwing good money after bad. A technician who tells you otherwise isn’t doing you a favor.
Do the air sealing at the same time. Hiring a crew to air seal and then hiring a second crew to insulate costs more overall because you’re paying for two mobilizations. Combining them saves $400 to $800 on a typical San Francisco attic.
Ask about rebates. BayREN, the Bay Area Regional Energy Network, periodically offers insulation incentives for qualifying homeowners. PG&E has run weatherization rebate programs that cover a portion of attic insulation costs. These programs change frequently, and we’re happy to point you toward current options when you call.
The simplest way to understand your cost is to get a written estimate. Our estimates are free, and they come as a line-item number you can hold in your hand before any work starts. Call (559) 245-9792 and you’ll reach a live person, day or night.
Insulation Material Options for San Francisco Homes
Blown-in Fiberglass
Blown-in fiberglass is the workhorse of San Francisco attic insulation. It installs quickly, settles predictably, and delivers R-38 in a standard 12 to 14 inch application. We install Owens Corning and Johns Manville blown-in fiberglass systems. The cost for a typical 1,200 to 1,500 square foot attic runs $1,800 to $3,200.
Blown-in Cellulose
Cellulose, made from recycled paper treated with fire retardant, costs slightly more than fiberglass but offers better air-blocking performance per inch. In older San Francisco homes with irregular joist spacing and lots of nooks, cellulose settles into gaps more effectively. GreenFiber is the brand we install most often. Expect $2,000 to $3,600 for a standard attic.
Spray Foam: Open-Cell and Closed-Cell
Spray foam costs the most, but it’s the right answer when you need air sealing and insulation in one step. Open-cell foam, at roughly $1.50 to $2.50 per board foot installed, expands to fill cavities and stops air movement. Closed-cell foam, at $2.50 to $4.50 per board foot, adds structural rigidity and acts as a vapor barrier. For San Francisco’s marine climate, open-cell on the attic floor with fiberglass over it is often the best value. We install Icynene and Demilec foam products.
Fiberglass Batts
Batts make sense for kneewalls, cathedral ceilings, and spaces where blown-in material won’t stay put. CertainTeed and Knauf manufacture the batt products we use. For a small kneewall job in a Marina district flat, batts might be the entire scope at $500 to $1,100.
The 365-Day Done Right Promise in Plain Terms
Every Alden Insulation San Francisco job includes a written guarantee valid for 365 days. Here’s what that means in practical terms: if the insulation fails to perform as specified within a year of installation, we come back and fix it at no charge. No proration, no service call fee, no argument about whose fault it is. The Garrison Standard applies to every job at every location, and this location is held to it.
The written price before work begins is part of the same discipline. You’ll know the material cost, the labor cost, and the total, itemized on paper, before a single tool comes off the truck. If the scope changes because we find something unexpected, we stop and walk you through the change in writing before proceeding. That’s the process Bryce Holloway has run in this market, and it doesn’t bend.
Our technicians arrive in uniform, on schedule, and background-checked. You’ll know who is walking into your home. Calls are answered by a live person, 24/7, not a voicemail tree.
Frequently Asked Questions
How much does attic insulation cost per square foot in San Francisco?
Attic insulation in San Francisco runs between $1.50 and $3.50 per square foot installed, depending on material type and whether removal is needed. Blown-in fiberglass sits at the low end; spray foam sits at the high end. For an exact number on your attic, call (559) 245-9792 and we’ll schedule a free estimate.
Is insulation removal necessary before installing new insulation?
Only if the existing material is water-damaged, moldy, rodent-contaminated, or contains vermiculite. Removal costs $1,500 to $3,000 for a typical San Francisco attic. If your existing insulation is dry and contamination-free, a top-off for $1,200 to $2,000 is usually sufficient. We’ll tell you which path applies to your attic during the free inspection.
What R-value does San Francisco require?
Title 24 requires R-30 minimum for attics in new construction and permitted renovations in San Francisco. For existing homes, the Department of Energy recommends R-30 to R-38 in Climate Zone 3. Most older San Francisco homes we inspect have R-11 or less, which means they’re losing heat at three to four times the recommended rate.
How much does air sealing cost in San Francisco?
Attic floor air sealing costs $600 to $1,400 for a typical 1,200 to 1,800 square foot home. The range depends on how many penetrations exist – recessed lights, plumbing vents, electrical boxes, and duct chases all get sealed. Air sealing without insulation is rarely worthwhile; the two go together.
Can you do the work the same week I call?
Yes, in most cases. We schedule insulation and air sealing jobs within five to seven business days of the written quote being approved. Smaller top-off jobs can sometimes be scheduled sooner. Call (559) 245-9792 and we’ll give you a specific date when we schedule the free estimate.
Get a Free, Written Estimate for Your San Francisco Home
Price questions are best answered by looking at your attic, not by guessing over the phone. Call Alden Insulation San Francisco at (559) 245-9792 for a free estimate. You’ll get a written price before any work begins, from a crew held to The Garrison Standard. Part of the Garrison Partners family since 2002, we’ve built our reputation on showing up, doing the work by the book, and standing behind it in writing for 365 days. If you’re researching insulation, start with one call.
Pricing reflects the San Francisco market as of 2026. Alden Insulation San Francisco offers free estimates – call (559) 245-9792.
Written by Bryce Holloway, Owner at Alden Insulation San Francisco, serving San Francisco since 2002.
What Our Customers Say
"Tidy crew. Vacuumed the hall and covered the hatch."
- Bea J."Spray foam in the rim joist. Floors above are warmer."
- Iris L."Blown-in insulation in the attic by a veteran crew. They air sealed the top plates first, installed baffles, and marked the depth with rulers. Bills dropped right away."
- Roy H.