Blown-In Attic Insulation in San Francisco, CA

Blown-In Attic Insulation in San Francisco, CA

Blown-in attic insulation in San Francisco typically costs $2,800 to $6,500 for a standard 1,200 to 1,800 square foot attic, depending on the current R-value and the material you choose. It is the fastest way to bring an under-insulated attic up to code and cut heating costs in a city where fog, wind, and damp air push into older homes year-round. Alden Insulation San Francisco installs blown-in fiberglass and cellulose using equipment that fills every cavity evenly, and every job starts with a written price before a single tool comes off the truck. If you are comparing this to batt insulation or spray foam, our Attic Insulation page breaks down the differences in plain terms.

This work is not a side project for a general contractor. Blown-in insulation has to be installed at the right density, at the right depth, and with the right ventilation to work correctly in San Francisco’s marine climate. We have been doing this since 2002 as part of the Garrison Partners family, and every crew member who walks into your home is background-checked and in uniform. Call (559) 245-9792 to schedule a free estimate.

Key Takeaways

• Blown-in attic insulation in San Francisco runs $2,800 to $6,500 for most homes, depending on square footage, current R-value, and material choice.
• Fiberglass and cellulose are the two main blown-in options; each has different moisture behavior and cost profiles, which matters in San Francisco’s fog-heavy neighborhoods.
• Every Alden job includes a written price before work starts and a 365-Day Done Right Promise in writing.
• Blown-in insulation is faster than batts and reaches corners and odd cavities that batts miss entirely.
• We answer calls with a live person 24/7, not a voicemail or an online form.

When You Need Blown-In Attic Insulation

Some attics are undersized for the job they need to do. In San Francisco, the signs show up as uneven room temperatures, a furnace that runs constantly in July fog or January cold, and energy bills that keep climbing without explanation. If you notice any of the following, your attic likely needs attention:

• Your attic insulation is below R-30. The California Energy Code requires R-30 minimum for most attic spaces in this climate zone. Many homes built before 1980 in the Sunset, Richmond, and Ingleside have R-11 or less, which means heat escapes straight through the ceiling.
• Rooms at the top of the house are always 8 to 12 degrees warmer or colder. That differential is almost always an attic insulation problem, not a thermostat problem. We see it constantly in Glen Park and Noe Valley homes where the top floor sits directly under an under-insulated attic.
• You can see the floor joists in your attic. If the joists are visible, you have less than 6 inches of insulation in most spots. That is functionally uninsulated by modern standards.
• Your home was insulated decades ago and the material has settled. Old fiberglass and cellulose settle over time. What was R-30 in 1985 is often R-12 or R-15 now. Blown-in installation restores the full depth in a day.
• Your heating bill is climbing, but your habits have not changed. In San Francisco, where PG&E rates are among the highest in the state, a poorly insulated attic can add $400 to $800 a year to a typical home’s energy cost.
• Drafts and cold spots persist even after sealing windows and doors. Heat rises. If the attic is not holding it, the rest of the house loses it. Air sealing plus blown-in insulation fixes the ceiling plane, which is the biggest single leak in most homes.

If any of these sound familiar, a free estimate will tell you exactly where you stand. You can reach us at (559) 245-9792.

Our Blown-In Attic Insulation Process

The process is straightforward, but the details matter. Here is what happens on every Alden blown-in insulation job in San Francisco:

1. Inspection and measurement. We inspect the attic, measure the square footage, check the current insulation depth and condition, and note any ventilation or air-sealing issues. We also check for moisture problems, which are common in San Francisco’s fog belt.
2. Written price and scope. You get a written estimate that lists the material, the target R-value, the depth required, and the total cost. That number does not change at the door. We do not do verbal estimates that turn into surprises.
3. Prep and air sealing. We seal the attic floor penetrations – wiring holes, plumbing chases, recessed light housings, and top plates – before blowing insulation. Without air sealing, insulation alone loses a significant portion of its effectiveness. If your attic needs vent baffles, we install those too.
4. Blown-in installation. We blow the insulation to the exact depth required to hit the R-value on your estimate. The machine runs a hose from the truck to the attic, and our technician works from the attic floor, filling every bay and corner evenly. Most installations take 3 to 5 hours.
5. Final inspection and cleanup. We check depth across the entire attic, confirm the target R-value, and clean the work area thoroughly. The written guarantee goes in your hand before we leave.

What R-Value Means for San Francisco Homes

R-value measures how well a material resists heat flow. Higher is better. The California Energy Code sets the minimum ceiling insulation at R-30 for San Francisco’s climate zone, but many of our customers choose R-38 or R-49 when their attic framing allows it. In foggy microclimates like the Outer Sunset, Outer Richmond, and the Excelsior, the extra depth pays for itself in the first two or three winters because the marine layer is a relentless heat thief.

Here is a straightforward cost-to-R-value reference for blown-in installation in a typical 1,500 square foot San Francisco attic:

• R-30 (about 10 to 11 inches of blown fiberglass): $3,200 to $4,000 installed
• R-38 (about 13 to 14 inches): $3,800 to $4,800 installed
• R-49 (about 16 to 17 inches): $4,500 to $6,500 installed

Cellulose runs slightly higher per R-value because the material is denser and requires more pounds per square foot to hit the same number. These figures include air sealing of the attic floor and standard prep. Your exact price depends on your attic’s accessible square footage and the condition of what is already up there.

Materials We Install: Fiberglass, Cellulose, and Moisture Reality

We install blown-in insulation from brands you can research on your own before you commit. On most San Francisco jobs, we work with CertainTeed fiberglass, GreenFiber cellulose, and Owens Corning products. For homes in the foggiest western neighborhoods, we often recommend GreenFiber cellulose because it handles moisture better than older fiberglass and settles into a dense, even blanket. For attics with existing attic batt insulation, blown-in CertainTeed fiberglass fills gaps and tops off low spots without removing what is already there.

Every material has tradeoffs. Cellulose is denser and holds R-value better when temperatures drop, but it is heavier and can settle if not installed at the right density. Fiberglass is lighter and does not settle as dramatically, but it can lose some effectiveness in very cold weather without a proper air seal. We walk you through the tradeoffs for your specific attic before you make a decision, not after.

Blown-In Attic Insulation Pricing in San Francisco

As a general rule, most blown-in attic insulation projects in San Francisco run $2,800 to $6,500, depending on square footage, current R-value, and material choice. Small attics under 1,000 square feet can come in under that range. Large attics over 2,000 square feet, especially when they need old insulation removal first, can push higher. No matter the number, you get a written price before any work begins. That is the only way we do business.

Here is what moves the price:

• Attic square footage. More area means more material and more labor. A 900 square foot attic in a Potrero Hill rowhouse costs less than a 2,200 square foot attic in a St. Francis Wood single-family home.
• Current insulation depth. If your attic already has R-19 but you want R-38, that is a top-off job and costs less than starting from a bare attic floor. If the existing insulation is wet or contaminated, it has to come out first.
• Material choice. Cellulose typically runs 15 to 25 percent more than fiberglass for the same R-value because it takes more pounds of material per square foot.
• Air sealing scope. Attics with lots of penetrations – dozens of recessed lights, HVAC runs, plumbing chases – take more prep time. The air sealing work is worth every dollar, but it does add labor.
• Access difficulty. A pull-down stair or wide scuttle makes the job simple. A cramped hatch in a closet ceiling slows things down and may require a different setup.

You can call (559) 245-9792 any time to get a free written estimate. A live person answers, not a voicemail. Estimates are free, the price is in writing before you approve anything, and the number on the invoice matches the number on the estimate.

Why San Francisco Homeowners Choose Alden Insulation

Plenty of companies can blow insulation into an attic. What separates Alden is the discipline behind the job. We are part of the Garrison Partners family, established 2002, and every location operates under The Garrison Standard. That means written prices, written guarantees, background-checked technicians, and a crew that shows up inside the window it promised. No vague half-day ranges. No price revised at the door. No mess left in your hallway.

The 365-Day Done Right Promise is the centerpiece. Every blown-in insulation job is covered by a written guarantee for a full year. If the work fails within that period, we come back at no charge. The guarantee includes a free second visit if a repair fails within the window. Not a prorated credit. Not a phone tree. A return visit by a uniformed technician who fixes the problem.

Our crews work with products from CertainTeed, Icynene, Demilec, and GreenFiber – brands any homeowner can look up independently before saying yes. You do not have to take our word for what goes into your attic.

Frequently Asked Questions

How much does blown-in attic insulation cost in San Francisco?

Blown-in attic insulation in San Francisco typically costs between $2,800 and $6,500 for a standard attic, depending on square footage, current R-value, and whether you choose fiberglass or cellulose. Small attics can come in under $2,800, and large attics with old insulation removal can exceed $6,500. Call (559) 245-9792 for a free written estimate with an exact number for your attic.

How long does blown-in attic insulation installation take?

Most blown-in attic insulation installations in San Francisco take 3 to 5 hours of work on site, from prep through cleanup. Attics that need full air sealing or old insulation removal can take a full day. You will know the timeline before we start, because it is in the written scope you approve.

Can you install blown-in insulation over existing attic insulation?

Yes, blown-in insulation can be installed directly over existing attic insulation as long as the existing material is dry, uncontaminated, and not compressed beyond use. This is called a top-off and it is one of the most cost-effective ways to raise an under-insulated attic to R-38 or R-49 without a full removal.

Is blown-in insulation better than batt insulation?

Blown-in insulation fills corners, odd cavities, and around obstacles far more completely than batt insulation, which leaves gaps wherever it is cut or compressed. For most San Francisco attics with irregular framing, plumbing runs, and wiring, blown-in is the better choice for even coverage and consistent R-value. Batt insulation still has its place, and we will tell you honestly which fits your attic.

Do you remove old attic insulation before blowing in new?

We remove old insulation only when it is wet, moldy, rodent-contaminated, or so compressed it no longer functions. Most San Francisco attics do not need full removal; they need a top-off or a fresh layer over sound existing material. If removal is necessary, you will see it itemized in the written estimate before you approve anything.

Common San Francisco Attic Problems We See

San Francisco’s climate creates a specific set of attic conditions. We are in and out of attics across the city every week, and the patterns are consistent. In the Outer Richmond and Outer Sunset, fog intrusion keeps attic sheathing damp for months at a time, which means ventilation and baffle installation matter as much as the insulation itself. In Noe Valley and Bernal Heights, old lath-and-plaster homes from the 1920s and 1930s often have no air sealing at all, so heat escapes through dozens of small openings around light fixtures and wall top plates. In the Mission and Potrero Hill, flat-roof townhomes often have very shallow attic cavities where only blown-in insulation can reach the tight spaces between joists.

These differences are why every job starts with an inspection, not an assumption. The attic tells us what it needs. Our job is to listen and install accordingly.

The Garrison Standard: What It Means for Your Job

The Garrison Standard is a set of non-negotiable operating rules that every Garrison Partners location follows. For you, it means three concrete things. First, the written price you approve is the price on the invoice. No change orders slipped in at the end. No “unexpected complications” upcharges. Second, every technician who enters your home is background-checked and arrives in uniform, so you know exactly who is walking through your door. Third, every job is backed by the 365-Day Done Right Promise – a written guarantee that if the work fails within a year, we return and make it right at no charge.

This is not marketing language. It is the operating code we have followed since 2002, and it is the reason homeowners who have been burned by other contractors end up calling Alden.

About Alden Insulation San Francisco

Alden Insulation San Francisco is an independently owned and operated insulation contractor, part of the Garrison Partners family since 2002. We specialize in blown-in attic insulation, attic insulation installation, and insulation removal for residential homeowners across San Francisco, from the Richmond and Sunset districts to the Mission, Potrero Hill, Noe Valley, and every neighborhood in between. We install products from CertainTeed, Icynene, Demilec, and GreenFiber, and we stand behind every job with a written 365-day guarantee. Our home page has more about the company and the full scope of services we provide.

If you are researching attic insulation options in San Francisco, start with our Attic Insulation in San Francisco guide for a broader look at materials, pricing, and what to expect from a professional insulation contractor. When you are ready for a specific number for your attic, call us at (559) 245-9792 for a free written estimate. A live person answers, 24/7.

Written by Bryce Holloway, Owner at Alden Insulation San Francisco, serving San Francisco.