Attic Insulation Cost in Texas (2026)

Attic Insulation Cost in Texas

Blown-in attic insulation runs $1.00 to $2.20 per square foot installed in Texas, which puts a typical 1,500-square-foot attic between $1,500 and $3,300. Spray foam costs considerably more — $1.50 to $3.00 per square foot for open cell and $3.00 to $5.00-plus for closed cell.

It is one of the highest-return improvements available on a Texas house. But the order you do things in matters more than the R-value you land on, and most homeowners get that order backwards. Blowing insulation over an attic full of unsealed penetrations and leaking ductwork buries the actual problem under fourteen inches of fiberglass.

The Short Version

• Blown-in fiberglass: $1.00–$1.80 per sq ft installed. Cellulose: $1.20–$2.20
• Fiberglass batts: $0.80–$2.00. Open-cell foam: $1.50–$3.00. Closed-cell: $3.00–$5.00+
• Removing old insulation: $1.00–$2.00 per sq ft
• Air sealing: $200–$600 added to the project — and the best money in this guide
• Radiant barrier: $0.50–$1.00 per sq ft
• Texas code target is R-49 in the attic; most existing Texas homes have R-19 to R-30
• A Texas attic runs 140–160°F in summer, with the roof deck hitting 180°F

Estimate Your Attic Insulation Cost

Use the calculator for a number based on your attic size and material, then read the sequencing section below — it is what determines whether you get the savings you are paying for.

Cost by Insulation Type

Type	Installed cost per sq ft	Where it fits
Blown-in fiberglass	$1.00–$1.80	The value default. Fast, cheap, does not settle much
Blown-in cellulose	$1.20–$2.20	Denser, better at slowing air movement, made from recycled paper
Fiberglass batts	$0.80–$2.00	Only good where the attic floor is open and joists are regular
Open-cell spray foam	$1.50–$3.00	Used to create a sealed, unvented attic. A different strategy, not an upgrade
Closed-cell spray foam	$3.00–$5.00+	Highest R per inch and a vapor barrier. Expensive, and rarely necessary on a Texas attic floor

For most Texas homes adding to an existing attic, blown-in fiberglass or cellulose is the right answer. Spray foam belongs in a different conversation — see the unvented attic section below.

Total Cost by Attic Size

Attic size	Blown-in fiberglass	Cellulose	Open-cell foam
1,000 sq ft	$1,000–$1,800	$1,200–$2,200	$1,500–$3,000
1,500 sq ft	$1,500–$2,700	$1,800–$3,300	$2,250–$4,500
2,000 sq ft	$2,000–$3,600	$2,400–$4,400	$3,000–$6,000
2,500 sq ft	$2,500–$4,500	$3,000–$5,500	$3,750–$7,500

Those are new-install numbers with no removal. If the old insulation has to come out first, add $1.00 to $2.00 per square foot — a remove-and-replace on a 1,500-square-foot attic typically lands between $3,000 and $7,500.

How Much Insulation Do You Actually Need?

Texas adopted the 2021 IECC at the state level, and it calls for R-49 in the ceiling in both of the climate zones that cover the populated parts of the state. Practical targets:

Region	Climate zone	Minimum	Recommended
Houston, San Antonio, Corpus Christi and the Gulf Coast	Zone 2	R-38	R-49
Dallas, Fort Worth, Austin, El Paso	Zone 3	R-38	R-49
The Panhandle	Zone 4	R-49	R-60

In blown fiberglass, R-49 is roughly 16 to 18 inches deep. Most existing Texas homes carry R-19 to R-30 — call it 6 to 10 inches — because that is what code required when they were built.

A quick self-check: go up with a tape measure and a flashlight. If the insulation is level with or below the top of the ceiling joists, you are somewhere around R-19 and there is a lot of room to improve. If you can see the joists as ridges across the whole attic, same conclusion.

Going past R-60 is diminishing returns. The difference between R-19 and R-38 is large; the difference between R-49 and R-60 is small. Do not let anyone sell you R-70.

The Texas Attic Is a 150-Degree Oven — With Your Ductwork In It

This is the part that makes attic work different here than anywhere in the north. A Texas attic in July sits at 140 to 160 degrees, and the underside of the roof deck can reach 180. And in the overwhelming majority of Texas homes, the air conditioner’s supply ducts run through that space.

Think about what that means. Your system chills air to about 55 degrees and then pushes it through flexible ducts sitting in a 150-degree oven, through connections that were taped twenty years ago. Leaky, poorly insulated attic ductwork can throw away a large share of what the air conditioner produces before it ever reaches a room — and it does it at exactly the hour you need it most.

Which is why “add more insulation” is often the second-best answer. If your ducts are leaking, insulation on the attic floor does nothing about it. Have the duct system inspected and sealed as part of the same visit. It frequently costs less than the insulation and saves more.

If rooms at the far end of the house never cool down, that is a duct symptom, not an insulation symptom, and possibly an equipment sizing one. Our AC replacement cost guide covers what that conversation looks like.

Do These in Order: Air Seal, Duct Seal, Insulate, Radiant Barrier

The sequence matters, and skipping straight to step three is the most common and most expensive mistake in this trade.

1. Air seal — $200 to $600. Insulation slows heat; it does not stop air. Every recessed light can, plumbing stack, bath fan, wiring penetration, top plate and attic hatch is a hole between your house and that 150-degree attic. Sealing them with foam and caulk before the insulation goes in is the highest-return few hundred dollars on this page, and once the blown insulation is down, nobody is going back to do it.

2. Seal and insulate the ducts. Mastic on the connections, not cloth duct tape, which fails in attic heat. Insulated flex at R-8 where it is being replaced.

3. Insulate to R-49. Blown fiberglass or cellulose, blown evenly, with baffles at the eaves so the soffit vents do not get buried.

4. Radiant barrier, if the budget allows. Details below.

Radiant Barrier: The Upgrade That Only Makes Sense in Hot Climates

A radiant barrier is a reflective foil applied to the underside of the roof deck or the rafters. It does not have an R-value in the usual sense — it works by reflecting radiant heat rather than slowing conduction, which is why it is close to useless in Minnesota and genuinely valuable here.

At $0.50 to $1.00 per square foot, a properly installed radiant barrier reduces attic temperatures by 20 to 30 degrees and cuts summer cooling costs by roughly 5 to 15 percent. The savings land at the high end of that range in exactly the situation most Texas homes are in: ductwork running through the attic. Cooler attic, less heat gained by the ducts, more of the cold air arriving where you wanted it.

Two cautions. It has to be installed with an air gap facing the attic space — foil laid flat on top of insulation collects dust, loses reflectivity and does very little. And it is not a substitute for insulation; it is an addition to it. Anyone selling radiant barrier as a replacement for R-value is selling you a story.

Ventilation: The Part Everyone Skips

Insulation and ventilation work together. A sealed-off attic with plenty of insulation and no airflow still bakes, and the trapped moisture shortens the life of the roof deck from underneath.

The residential code baseline is 1 square foot of net free vent area per 150 square feet of attic floor, which can be relaxed to 1:300 when intake and exhaust are balanced between the soffits and the ridge. For a 2,000-square-foot attic, the 1:150 figure works out to roughly 13 square feet of net free area.

The most common failure is not too few vents — it is blocked soffit vents, buried by blown insulation that was pushed too far out into the eaves. Insist on baffles at every rafter bay. It is a small line item, it is often left out, and without it the ventilation you paid for at the ridge has nowhere to draw air from.

Remove the Old Insulation, or Add on Top?

Adding on top is normal and usually correct. Old fiberglass that is dry and intact still has its R-value, and blowing over it is cheaper and faster than a tear-out.

Remove first if any of these apply:

• Rodent contamination — droppings, nesting, or a persistent smell
• Water damage from a roof leak, or any visible mold on the insulation or decking
• Insulation that is matted, compacted, or has been repeatedly walked on
• Vermiculite, which may contain asbestos and requires testing and specialist handling — do not disturb it yourself
• Smoke or fire damage

Removal runs $1.00 to $2.00 per square foot, so it can nearly double a project. If a contractor recommends full removal, ask them to show you why, with photographs from the attic. If there is water damage up there, deal with the source first — see our roof and water damage and mold guides.

What About Spray Foam and the Unvented Attic?

Spray foam applied to the underside of the roof deck creates a sealed, unvented attic that is brought inside the building envelope. Done correctly it is genuinely effective in Texas: the attic stays within about ten degrees of the house, and the duct problem largely disappears because the ducts are no longer in a hostile space.

It is also a much bigger decision than adding insulation. It costs several times as much, it is essentially permanent, it changes how the roof deck dries, and it interacts with combustion appliances and ventilation in ways that need to be designed rather than assumed. It requires a contractor who does this specific work regularly, not one who added it to the truck last year.

For most Texas homeowners with a working vented attic, the sequence in this guide — air seal, duct seal, R-49, radiant barrier — delivers most of the benefit for a fraction of the price.

What the Quote Usually Leaves Out

• Air sealing — frequently not included unless you ask, and the single most valuable item
• Baffles at the eaves, without which the new insulation blocks the soffit vents
• An insulated, weatherstripped attic hatch — a large uninsulated hole in an otherwise good ceiling
• Recessed light covers, required where fixtures are not IC-rated
• Bath and dryer vents that terminate in the attic instead of outside — very common, and a mold problem
• Removal of the existing material, if needed
• Duct sealing, usually a separate HVAC trade
• Decking or a walkway if you use part of the attic for storage — and note that storage decking compresses insulation to nearly nothing beneath it

Questions to Ask an Insulation Contractor

• What R-value am I at now, and what will I be at when you are done?
• Is air sealing included, and what specifically will you seal?
• Are you installing baffles at the eaves?
• How many inches of material is that, and how do you verify depth across the whole attic?
• Will you insulate and weatherstrip the attic hatch?
• Are any bath fans or dryer vents currently discharging into the attic?
• Do you seal ducts, or should I have my HVAC company do that first?
• Do you carry general liability and workers’ compensation?

One more: ask whether your electric utility offers a rebate. Several Texas providers run residential efficiency programs that cover part of attic insulation and air sealing. Check our savings and rebates page before you book the work, not after — most programs require pre-approval.

Frequently Asked Questions

How much will attic insulation actually save me?

It depends entirely on where you are starting. Going from R-19 to R-49 with air sealing produces a noticeable change in comfort and a real reduction in summer cooling cost. Going from R-38 to R-49 does not. The homes that see the biggest savings are the ones with the least insulation and the leakiest ceilings — which is most Texas homes built before the mid-2000s.

Fiberglass or cellulose?

Both work. Cellulose is denser and slows air movement a little better; fiberglass will not absorb water if you get a roof leak and does not settle as much over time. Price is close. Either is a good choice, and the installer’s care matters more than the material.

Can I add attic insulation myself?

Blown insulation is a realistic DIY project — home centers rent the blower, often free with a material purchase — but a Texas attic in summer is dangerous, and the work is best done early on a cool morning. Air sealing is the DIY task most worth doing yourself, because it is cheap in materials and expensive in labor. Do not disturb anything that might be vermiculite.

Does attic insulation help in winter too?

Yes, and Texas homeowners underrate this. The same ceiling that lets heat in during August lets it out in January, and after the winter storms of recent years the case for a well-insulated, well-sealed attic is not only about the electric bill.

How long does the work take?

A straightforward blow-in over existing insulation is a half day to a day. Add a day if the old material is being removed. Air sealing adds two to four hours and is worth every minute.

The Bottom Line

Budget $1,500 to $3,300 for blown insulation on a typical 1,500-square-foot Texas attic, and target R-49. But spend the first $200 to $600 on air sealing, and ask about the ductwork before you ask about the R-value.

In a state where the attic hits 150 degrees and the air conditioning runs through it, the ceiling between you and that space is the most valuable surface in the house. Seal it, insulate it properly, keep the soffit vents clear, and add a radiant barrier if there is room in the budget. Together that is a few thousand dollars against a cooling bill you pay every summer for as long as you own the house.