How Much Does Insulation Cost in San Francisco?
Attic insulation in San Francisco typically costs between $1,800 and $6,500 for a full installation, with most homes landing in the $2,400 to $4,200 range. Spray foam insulation runs higher, usually $4,500 to $12,000 depending on square footage and whether you’re insulating an attic, crawl space, or rim joists. You’ll get a written price before any work starts at Thistledown Insulation San Francisco, so the number you sign off on is the number you pay.
Insulation Cost Breakdown (2026)
Here’s what insulation work actually costs in San Francisco right now. These figures reflect the local market for homes built before 1980, which covers most of the Richmond, Sunset, Noe Valley, and Bernal Heights housing stock we work in every week.
| Insulation Type / Project | Typical Cost Range (San Francisco, 2026) | Best For |
|---|---|---|
| Attic blow-in fiberglass (1,200 sq ft attic) | $1,800 – $3,200 | Most SF homes; fast install, solid R-value per dollar |
| Attic blow-in cellulose (1,200 sq ft attic) | $2,100 – $3,800 | Older attics with gaps and irregular joist spacing |
| Batt insulation (fiberglass or Rockwool, 800 sq ft) | $1,500 – $2,900 | Attics with open, accessible joist bays |
| Open-cell spray foam (attic roof deck, 1,000 sq ft) | $4,500 – $8,200 | Unvented attics, rooms over garages, sound dampening |
| Closed-cell spray foam (rim joists + crawl space, 300-500 sq ft) | $3,800 – $6,800 | Moisture-prone areas, seismic shear value, air sealing |
| Crawl space insulation (fiberglass or foam board, 600 sq ft) | $2,400 – $5,100 | Homes in the Outer Sunset and Ingleside with raised foundations |
| Air sealing + attic insulation combo (most common package) | $2,800 – $5,400 | Older SF homes where drafts are the real problem |
| Insulation removal (old, damp, or rodent-soiled material) | $900 – $2,200 | Attics with 30+ year-old fiberglass or pest contamination |
These are installed prices, including labor, materials, and clean-up. If you’re getting quotes far below these numbers, ask what’s being skipped: removal of old material, air sealing, or the clean-up itself. We line-item every part of the job so nothing is a surprise on the invoice.
What Drives the Price Up or Down
Three things move insulation pricing in San Francisco more than anything else: attic accessibility, the age of what’s already up there, and whether the home has knob-and-tube wiring. Tight attic hatches in 1920s Mission District flats take longer to work through, which adds labor time. Older insulation that’s compressed, damp, or full of rodent droppings has to come out before anything goes in. And knob-and-tube wiring, still present in a surprising number of Portola and Excelsior homes, requires the insulation to be kept well clear of the conductors, which slows the install and changes material choices. Neil Barron walks each homeowner through these variables before quoting, so the price reflects your attic, not a generic square-footage formula.
What Affects Insulation Pricing in San Francisco
- Attic size and layout. A 900 square foot attic in a Sunset District row house costs less than a 1,600 square foot attic in a Marina or Pacific Heights single-family home. Low-slope roofs with tight clearances add labor hours.
- Access point size. Many San Francisco homes have attic hatches that are 22 inches wide or smaller. If the hatch needs to be enlarged or if materials have to be cut to fit through, that’s extra time and cost.
- Existing insulation condition. Attics in the Richmond and Sunset get hit with salt air and fog moisture every summer. Wet or compressed insulation must be removed before new material goes down, which adds $900 to $2,200 to the project.
- Air sealing needs. In San Francisco, the gaps around recessed lights, plumbing penetrations, and chimney chases are often the bigger energy problem than thin insulation. Air sealing adds $600 to $1,400 but is usually the highest-value work on the invoice.
- Rodent or pest remediation. The Outer Sunset, Excelsior, and Glen Park have their share of roof rats. If droppings or nesting material are present, we recommend removal and sanitization before new insulation, which adds cost but protects the air your family breathes.
- Material choice. GreenFiber cellulose and Johns Manville fiberglass are the workhorses and cost less per square foot than Rockwool batts or Icynene spray foam. We match the material to the attic, not to a margin target, across eight brand lines: Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and GreenFiber.
Attic Insulation vs. Spray Foam: Which Costs More and Why
Spray foam costs more than blown-in insulation, full stop. In San Francisco, open-cell spray foam runs $4.50 to $8.20 per square foot installed, while blown-in fiberglass or cellulose runs $1.50 to $3.20 per square foot. The reason is simple: spray foam is a two-part chemical that requires specialized equipment, temperature control, and crew training. Blown-in insulation uses a machine to shred and distribute material, which is faster and uses less labor.
That said, spray foam earns its price in specific San Francisco situations. If you have an unvented attic, meaning the roof deck is the only barrier between living space and sky, spray foam is often the only insulation that performs correctly. The same goes for rooms over unconditioned garages in Noe Valley or Bernal Heights, where cold floors are the complaint. Closed-cell spray foam also adds structural rigidity, which matters in a city that takes seismic retrofitting seriously. Neil Barron and the team at Thistledown will tell you plainly if $1,800 worth of blown-in fiberglass will do the job as well as $7,000 worth of foam. We’ve talked more than one family out of spending more than they needed to.
How Much Does Insulation Save on Energy Bills in San Francisco?
A properly insulated and air-sealed attic in San Francisco typically cuts heating costs by 15% to 25% per year. For a two-bedroom home in the Sunset or Richmond with gas heat, that’s roughly $180 to $400 annually, depending on how drafty the house is now and how warm you keep the thermostat. The payback on a $2,800 air-sealing-plus-insulation job often lands between 7 and 12 years from energy savings alone.
But energy savings are only part of what you’re buying. The louder, more immediate benefit is comfort. San Francisco homes sit in a marine layer for months at a time, and a poorly insulated attic lets damp, cold air fall through the ceiling all day. In the Outer Richmond, where fog sits on the roof until noon in July, an insulated attic is the difference between a bedroom that holds at 58 degrees and one that holds at 66 without running the furnace. Families with young children feel this most acutely in the nursery, where a cold ceiling drops the room temperature faster than any other room in the house.
How to Save on Insulation
Insulation is not a place to go cheap, but there are real ways to keep the total reasonable without cutting into the parts that matter.
- Bundle air sealing with insulation. Doing both at once saves $400 to $800 compared to scheduling them separately, because the crew is already in the attic with the equipment set up.
- Rebate-check before you commit. BayREN and PG&E run insulation and air-sealing rebate programs that shift year to year. We’ll check current program status for your address as part of the free estimate.
- Choose the right material for the right spot. If your attic is vented and accessible, blown-in fiberglass from Johns Manville or Knauf does the R-value job for less than foam. Save spray foam budgets for crawl spaces and rim joists where it earns its keep.
- Get three written line-item quotes, not one big number. A quote that says “attic insulation: $4,500” without breaking down removal, air sealing, material, and labor is hiding something. Every Thistledown quote is line-itemed before you sign anything.
- Ask about the cleanup before you book. Some crews leave dust and fiberglass particles in the hallway. The cost of dealing with that, either in your own cleaning time or a follow-up cleaner, is real. We lay drop cloths from the front door to the attic hatch, wear shoe covers the entire time, and leave a photo of the clean-up before we pull the van away. That’s the Cedarwell Care Promise, and it’s included in every price we write.
Call (341) 247-0222 for a free estimate and you’ll get a written price before any work begins. No pressure, no “limited time” language, just the number for your attic.
FAQs – Insulation Cost
How much does attic insulation cost per square foot in San Francisco?
Attic insulation in San Francisco runs $1.50 to $3.20 per square foot installed for blown-in fiberglass or cellulose, and $4.50 to $8.20 per square foot for spray foam. A typical 1,200 square foot attic with blown-in insulation lands between $1,800 and $3,800 total. Your written quote from Thistledown will break out the per-square-foot rate so you can compare apples to apples. Call (341) 247-0222 and we’ll measure your attic and give you the exact number.
Is it cheaper to insulate yourself or hire a pro in San Francisco?
DIY blown-in insulation can look cheaper on paper, with machine rental and materials running $800 to $1,400 for a small attic, but San Francisco attics are rarely straightforward. Tight hatches, knob-and-tube wiring, and damp existing material all demand experience. A pro job for a standard SF attic starts around $1,800 and includes air sealing, which DIY jobs typically skip. The gaps around recessed lights and plumbing vents are where the heat actually leaves, and a rented machine won’t fix that. Call (341) 247-0222 for a line-item quote and compare it against the rental receipt yourself.
How much does spray foam insulation cost in San Francisco?
Open-cell spray foam in San Francisco costs $4.50 to $8.20 per square foot installed, putting a 1,000 square foot attic roof deck between $4,500 and $8,200. Closed-cell foam runs higher, typically $6.00 to $10.00 per square foot, and is usually reserved for rim joists, crawl spaces, and seismic shear applications. We install Icynene and Demilec spray foam products and will tell you honestly if blown-in insulation would do the job for less. Call (341) 247-0222 and we’ll quote both options for your attic.
Does insulation increase home value in San Francisco?
Insulation rarely moves the appraisal needle the way a remodeled kitchen does, but it absolutely moves the buyer-comfort needle in San Francisco’s cold, foggy neighborhoods. A home inspection that finds a dry, properly insulated attic with documented air sealing gives buyers one less reason to negotiate $2,000 to $5,000 off the price. In the Outer Sunset and Richmond, where fog is a daily reality, a warm, dry attic is a quiet but real selling point.
Can you come today for an insulation estimate in San Francisco?
We answer every call with a live person, 24 hours a day, 7 days a week. Same-day or next-day estimates are common for San Francisco addresses, and every estimate includes a written price before any work begins. Call (341) 247-0222 and we’ll schedule a walkthrough of your attic that fits your calendar, not ours.
Why San Francisco Homeowners Choose Thistledown Insulation
Thistledown is the soft fluff of the thistle, one of nature’s lightest insulators. The name is a promise about how carefully we work. We’re an independently owned member of the Cedarwell family, founded in 2003, and we install attic and spray foam insulation to the Cedarwell Care Promise standards on every single visit.
What that looks like in your home: shoe covers go on at the front door and stay on until we’re back outside. Drop cloths run from the entry to the attic hatch. We ask before we move or touch anything. We use quiet tools when children are sleeping, and we choose pet-safe insulation products where a choice exists, so the dog can stay home during the job. Before the van pulls away, we photograph the clean-up and leave the space as we found it, or cleaner.
We install eight insulation brands: Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and GreenFiber. That range matters because no single material is right for every San Francisco attic. A fog-soaked Outer Sunset attic needs a different approach than a dry, sunny Potrero Hill attic. We match the product to the house and to the family living in it. And every job, from a $1,800 blow-in to a $12,000 full spray foam retrofit, is backed by our 365-Day Done Right Promise. If it’s not done right, we make it right. No debate, no fine print.
Neil Barron and the Thistledown team have been insulating San Francisco attics long enough to know that the question isn’t just “how much does it cost” but “what will my house feel like afterward.” The answer to the first question is in the table above. The answer to the second is something we show you in writing, before any work begins, every time.
Get Your Insulation Price in Writing
Call Thistledown Insulation San Francisco at (341) 247-0222 and we’ll schedule a free estimate at a time that works for your family. Neil or a member of the crew will walk the attic, measure the space, check for air leaks and old material, and hand you a written line-item price before we touch a rafter. You’ll know exactly what’s being installed, what it costs, and what the floors will look like when we leave.
Pricing reflects the San Francisco market as of 2026. Thistledown Insulation San Francisco offers free estimates – call (341) 247-0222.
What Our Customers Say
"Our bedrooms were always cold. They added insulation and air sealed the attic, and were meticulous about cleanup, you'd never know they'd been in the attic. So much cozier now."
- Donna Petrie"Attic insulation with a baby in the house. The crew was quiet, clean, and protected every floor they crossed. Took away all the debris and left it tidy. Already feeling the difference in comfort."
- Omar Leon"Spray foam in the garage and new attic insulation. Considerate, calm crew that protected the floors and kept the dust down with our little ones around. Explained it all patiently."
- Hassan Qureshi