Blown-In Insulation Cost - Same-Day Service, Done Right the First Time

How Much Does Blown-In Insulation Cost in San Antonio?

Blown-in insulation in San Antonio typically costs between $1,850 and $4,600 for a standard 1,500 – 2,000 square foot attic, with most homeowners paying around $2,800. Fiberglass runs $1.10 – $2.30 per square foot installed, while cellulose costs $1.40 – $2.80 per square foot. Those numbers vary with your attic’s current condition, access, and whether old insulation needs to come out first. At Thistledown Insulation San Antonio, you’ll get a written price before any work begins, so the number we quote is the number you pay.

If you want to skip ahead: we break down every line item below, explain what drives San Antonio pricing, and list the questions we hear most from homeowners across Alamo Heights, Stone Oak, Helotes, and the neighborhoods in between. You can also call (903) 437-9164 and talk to a live person, any hour, for a straightforward conversation about your attic.

Key Takeaways

• Most San Antonio attics cost $1,850 – $4,600 to insulate with blown-in material.
• Cellulose costs slightly more than fiberglass but holds its R-value better in our humidity swings.
• Attic prep, old insulation removal, and air sealing add to the total, typically $500 – $2,000 combined.
• Every Thistledown quote is written, itemized, and fixed before the first tool comes off the truck.
• Free estimates at (903) 437-9164, answered by a real person 24/7.

Blown-In Insulation Cost Breakdown (2026)

Here is what a typical blown-in insulation job looks like in San Antonio, line by line. These figures reflect what we see across the city in 2026 for a standard single-family home with an accessible attic and no major prep issues.

A few things push the total up or down. If your attic is tall, open, and easy to move around in, labor stays low. If it’s a low-slung 1970s ranch in Castle Hills with tight trusses and a furnace in the middle of the walkway, that takes more time. Recessed lights need careful attention around each fixture, which adds time per can. And if the existing insulation is wet from a roof leak or full of rodent droppings, it has to come out before anything new goes in.

We install all blown-in insulation in San Antonio using eight brand lines: Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and GreenFiber. That matters because one product fits certain attics better than another. A homeowner with pets and kids on the second floor may prefer a pet-safe option where one exists. A homeowner with a ductwork-heavy attic may benefit from the density of cellulose. We explain the trade-offs in plain language and put the recommendation in writing before we start.

What Affects Blown-In Insulation Pricing in San Antonio

San Antonio has its own set of factors that influence what a blown-in insulation job costs. Some are about the house. Some are about the climate and how we build here. Here are the ones that move the number most:

• Existing insulation condition. Homes built before 1990 often have compressed fiberglass batts or settled cellulose that has lost most of its R-value. In neighborhoods like Terrell Hills and Oak Park-Northwood, it’s common to find 2 – 4 inches of material where 13 – 15 inches should be. Replacement requires removal, which adds cost but is non-negotiable for the new insulation to perform.
• Attic access and layout. A pull-down stair in a hallway closet is quick work. A scuttle hole in a tight garage corner with a water heater underneath is slow work. San Antonio ranches from the 1950s and 1960s often have low roof pitches and cramped attics that add 30 – 60 minutes of labor.
• Air sealing scope. The number of penetrations in your attic floor directly affects both the price and the comfort result. Top plates, wire chases, and can lights all need sealing. A 1,800-square-foot home in Stone Oak might have 40+ penetrations. An older home in Government Hill could have fewer but larger gaps around old chimneys or dropped soffits.
• R-value target. San Antonio sits in climate zone 2A according to the Department of Energy, which recommends R-30 to R-49 for attics. Meeting the minimum is cheaper. Going to R-49 means more material and more labor. We’ll tell you the payback difference so you can decide with real numbers, not a salesman’s nudge.
• Material choice. Fiberglass is lighter and less expensive. Cellulose is denser, better at blocking air movement, and often a better choice for sound between floors. Rockwool can be blown in specific applications where fire resistance matters. We match the product to the attic, not the other way around.
• Season and scheduling. San Antonio attics hit 130°F+ from June through September. Working in that heat is slower and demands more hydration breaks and safety awareness. If you can schedule outside peak heat months, labor efficiency improves. If you need it done in August, we’ll do it carefully and safely, but it takes longer, and that’s reflected in the price honestly.

One more thing worth saying plainly: we never give a phone estimate and then show up with a different number. Our crew lead walks the attic, measures, checks for moisture, looks at the venting, and writes the price. That price is the price. Neil Barron and the Thistledown team built the company on that commitment in 2003, and it hasn’t changed.

How Much Does It Cost to Add Blown-In Insulation to an Existing Attic in San Antonio?

Adding blown-in insulation on top of existing material costs less than a full removal-and-replace. If the existing insulation is dry, pest-free, and reasonably even, we can blow new material directly over it. Expect $1,100 – $2,400 for a typical 1,200-square-foot attic at R-38 depth. The existing insulation stays in place, and the new layer fills gaps and brings the total R-value up to current recommendations.

That said, topping off only works when the existing material is in decent shape. If you see moisture stains on the ceiling below, smell anything musty, or have had rodent activity, a top-off traps the problem under a new layer. We’ll tell you if that’s the case during the estimate, and we’ll show you photos from inside the attic so you can see exactly what we’re seeing.

How Much Does Blown-In Cellulose Insulation Cost in San Antonio?

Cellulose runs $1.40 – $2.80 per square foot installed in San Antonio, putting a 1,500-square-foot attic at roughly $2,100 – $4,200. Cellulose is denser than fiberglass, which gives it a real advantage in our climate: it resists the convective air movement that pulls conditioned air through insulation in the summer. It also deadens sound, a detail parents in two-story homes notice immediately when the kids are running around upstairs.

We install GreenFiber and CertainTeed cellulose products. Both are treated with borates for fire and pest resistance. Both are safe for a home with kids and pets once installed. And both have an R-value per inch around 3.5, which means less depth needed compared to some fiberglass products to hit the same performance.

How Much Does Blown-In Fiberglass Insulation Cost in San Antonio?

Fiberglass runs $1.10 – $2.30 per square foot installed in San Antonio. For a 1,500-square-foot attic, that’s about $1,650 – $3,450. Fiberglass is lighter, so it works well in attics where ceiling structure or older drywall could be a concern. It also doesn’t settle quite as much as cellulose over decades, though modern installation techniques minimize settling with either product.

We carry Owens Corning, Johns Manville, and Knauf blown-in fiberglass. Each brand has slightly different material handling characteristics, and the crew lead picks the one that suits your attic’s ventilation and depth targets. You’ll see the brand name on your written estimate, not a generic “fiberglass insulation” line item.

What Does Blown-In Insulation Cost Per Square Foot in San Antonio?

Installed pricing in San Antonio runs $1.10 – $2.80 per square foot depending on material and scope. Here’s the simple math: fiberglass at $1.75 per square foot for a 1,400-square-foot attic is $2,450. Cellulose at $2.10 per square foot for the same attic is $2,940. Air sealing, baffles, and access work are additional line items we price separately so you can see exactly where every dollar goes.

Is Blown-In Insulation Worth the Cost in San Antonio?

For most San Antonio homes, yes. The attic is where 20 – 30% of a home’s conditioned air leaks out in the summer, and our cooling season runs from April through October. A house moving from R-11 to R-38 attic insulation delivers a measurable reduction in cooling load, which shows up on the CPS Energy bill within the first full summer. Homeowners regularly tell us their upstairs rooms hold temperature for the first time, which is a comfort gain that doesn’t show up on any spreadsheet.

At Thistledown, we back every job with the 365-Day Done Right Promise. If something’s not done right, we make it right. No debate, no fine print. That guarantee is why families in San Antonio trust us to be in their homes, including when the dog is home and the baby is napping.

How to Save on Blown-In Insulation in San Antonio

• Get the attic air sealed at the same time. Insulation without air sealing is like a jacket with the zipper open. Sealing first means the insulation performs as specified, and bundling the work costs less than doing them separately.
• Schedule outside the peak summer months. Attic work in San Antonio’s summer heat is slower and harder on the crew. October through April gives us better working conditions, which keeps labor costs down. If summer is your only option, we’ll still be there, just with more water breaks.
• Don’t pay for removal you don’t need. If your existing insulation is dry, pest-free, and not compressed, topping off is significantly less expensive than removal and replacement. We’ll show you photos and explain the recommendation honestly.
• Check for CPS Energy rebates and federal tax credits. San Antonio’s utility and federal programs sometimes offer incentives for insulation upgrades, especially when combined with other efficiency work. We’ll point you to the current programs, but we won’t inflate your price to “help” you qualify. That’s not how we operate.
• Call for a free estimate. Our estimates cost nothing and come with a written price. Call (903) 437-9164 and you’ll talk to a live person, get a time that works for your schedule, and have a crew lead walk the attic before quoting anything.

Our Blown-In Insulation Process

Here’s what happens when you call Thistledown Insulation San Antonio. It’s the same process Neil Barron has run since 2003, and it’s designed so you’re never surprised by anything: not the price, not the crew, not the mess.

1. You call and a person answers. Not a voicemail tree. Not a “we’ll call you back within one business day.” A live person, 24/7. You’ll tell us about your home, and we’ll schedule an attic inspection at a time that works for your family.
2. A uniformed, background-checked technician arrives. Shoe covers go on at the door. Drop cloths go down from the front door to the attic hatch. We ask before moving or touching anything. This is the Cedarwell Care Promise in action: Clean up like it is our own home; Ask before we move or touch anything; Respect the family’s time and quiet hours; Explain the price before the work.
3. We inspect the attic and explain what we find. You’ll see photos from inside your own attic. Not stock images. We’ll show you the current depth, any moisture concerns, venting issues, and the number of air leaks we found. Then we explain what we recommend and why.
4. You get a written price before any work starts. Every line item, every product, the total number. If you sign, that’s the price. If you don’t, you keep the estimate and get no pressure. That’s it.
5. We install with quiet tools. If the baby is napping or the dog is anxious, we adapt. The crew works carefully, cleans up fully, and takes photos of the finished clean-up before we leave. The van doesn’t pull away until you’ve seen the work.

Thistledown is the soft fluff of the thistle, one of nature’s lightest insulators. The name is a promise about how carefully we work.

FAQs – Blown-In Insulation Cost in San Antonio

How much does blown-in insulation cost for a 1,500 sq ft attic in San Antonio?

For a 1,500-square-foot attic, blown-in insulation in San Antonio costs $1,650 – $4,200 installed, depending on material and whether old insulation needs removal. Fiberglass runs $1,650 – $3,450, while cellulose runs $2,100 – $4,200. Call (903) 437-9164 for a free estimate with written pricing based on your actual attic.

Is blown-in insulation cheaper than batts?

Blown-in insulation typically costs 10 – 20% less than professionally installed batts in San Antonio, and it covers better because it fills gaps, corners, and around framing. Loose-fill material also avoids the thermal bypasses common with poorly fitted batts. If you’re comparing quotes, ask for a written line item so you can see what each contractor includes in the price.

How much does it cost to remove old insulation before blowing in new?

Old insulation removal in San Antonio costs $700 – $1,800 for a standard attic, depending on the material, access, and whether a dump trailer is needed. Removal is only necessary when the existing material is wet, pest-contaminated, or too compressed to perform. If the existing insulation is in decent shape, topping off is the better financial choice. We’ll show you photos from inside your attic so you understand exactly what’s needed.

Can you install blown-in insulation the same day?

Yes, in most cases. A standard blown-in insulation job in San Antonio takes 3 – 6 hours, which means we can often inspect in the morning and complete the installation before the school pick-up. Larger jobs, or those requiring old insulation removal and air sealing, may stretch into a full day or two. When you call (903) 437-9164, tell us your timeline and we’ll tell you honestly what fits.

Does blown-in insulation settle over time?

Modern blown-in cellulose settles about 10 – 15% in the first year, which is factored into the installation depth. Fiberglass settles less, typically under 5%. In San Antonio’s humid climate, proper installation techniques matter more than the product itself: if the material is installed at the correct density and depth, settling won’t compromise the R-value over the life of the home. We install to manufacturer specifications and back it with our 365-Day Done Right Promise.

Does Thistledown offer free estimates?

Yes. Every estimate from Thistledown Insulation San Antonio is free, includes a written price, and comes with no obligation. You’ll talk to a live person when you call (903) 437-9164, and a uniformed, background-checked technician will inspect your attic before quoting anything. The number on the written estimate is the number you pay, every time.

Get Your Written Blown-In Insulation Quote Today

If you’re in San Antonio and thinking about blown-in insulation, the next step is simple: call (903) 437-9164. A live person answers, day or night. We’ll schedule a time for a technician to inspect your attic, explain what you need with photos and plain language, and hand you a written price before any work begins. Shoe covers on. Drop cloths down. Clean-up photographed. That’s the Cedarwell-family way, and it’s how Thistledown Insulation San Antonio has served this city since 2003.

Pricing reflects the San Antonio market as of 2026. Thistledown Insulation San Antonio offers free estimates – call (903) 437-9164.

Written by Neil Barron, Owner at Thistledown Insulation San Antonio, serving San Antonio since 2003.