Attic Air Sealing Cost - Same-Day Service, Done Right the First Time

How Much Does Attic Air Sealing Cost in Boerne?

Attic Air Sealing services in Boerne, TX typically run between $850 and $2,400 for a standard single-story home, with most jobs in the 1,600-2,400 square foot range landing around $1,200-$1,600. That range covers sealing top plates, can light penetrations, plumbing and electrical chases, and attic hatch perimeters – the specific leak points that account for the majority of conditioned air loss in Hill Country homes. A blower-door test – a pressurization reading that shows, in one number, how much air your building envelope is losing – is included on applicable jobs so you can see exactly what changed.

Attic Air Sealing Cost Breakdown (2026)

The table below reflects real Boerne market pricing as of 2026. These are flat ranges, not bait-and-switch minimums. Under Haven Standard Clause 1, a written price is delivered before any work starts – no surprises when the crew finishes.

What Pushes the Number Up or Down

The single biggest driver is how many penetrations exist in the attic floor. A 1980s-era home in the older sections of Boerne near the Guadalupe River corridor can have 60-80 can light fixtures punched through the ceiling drywall with no air barrier at all. Each one is a direct hole from conditioned living space into an unconditioned attic. Sealing all of them with a fire-rated foam or rigid cover takes time, and time is what you are paying for. A newer construction home in a development like Esperanza or Balcones Creek built after 2015 may have ICAT-rated (insulation contact and air tight) fixtures already installed, dropping the penetration count significantly and pulling the job cost toward the lower end of the range.

Existing insulation also matters. If blown-in fiberglass or cellulose already sits in the attic and has to be pulled back to access the top plate, that adds labor. Some contractors skip this step and seal what they can reach from the top – which leaves the most critical leakage points untouched. At Envelope Insulation Co., air sealing of top plates, can lights, and penetrations is completed before any insulation is added or replaced. We don’t insulate over an unsealed attic floor.

What Affects Attic Air Sealing Pricing in Boerne

• Home age and construction era: Homes built before 1995 in Boerne’s historic district or the older neighborhoods along Main Plaza generally have minimal air sealing built in from original construction. These jobs run toward the top of the range because every penetration has to be addressed from scratch. Post-2015 construction typically starts at a better baseline.
• Attic access and working conditions: A steep 8/12 or 9/12 roof pitch – common on Spanish-style and Hill Country vernacular homes throughout Boerne – creates a taller attic but sometimes a trickier working environment near the eaves. Tight eave clearances add time. Boerne’s limestone terrain also means pier-and-beam foundations are uncommon, but when crawl space work is involved in the same project, the combined scope affects total pricing.
• Summer heat load on the attic floor: Boerne summers push attic temperatures past 140 degrees Fahrenheit on a south-facing roof deck. Foam sealants behave differently in sustained extreme heat, and the materials used for long-term performance in this climate – specifically two-component closed-cell spray foam for larger gaps and fire-rated caulk for smaller ones – cost more per linear foot than basic contractor foam but don’t break down over a Texas summer. Cutting corners on materials in this climate shows up in a repeat blower-door reading within two or three years.
• Number of HVAC and plumbing penetrations: Every pipe, wire bundle, flue, and duct boot that passes through the attic floor is a potential bypass. Homes with multiple HVAC systems – which is standard for anything above 2,800 square feet in the Boerne-Fair Oaks Ranch corridor – have proportionally more penetrations. Counting and sealing each one is what separates a real air sealing job from a partial one.
• Whether existing insulation must be moved: If the attic already has R-22 to R-30 of blown fiberglass and the top plates are buried, labor to carefully excavate and reset insulation adds roughly $200-$500 to the total depending on depth and coverage area. This is non-optional if you want the sealing done correctly.
• Bundling with other envelope work: Scheduling air sealing as a standalone job versus bundling it with insulation removal, radiant barrier installation, or a full home energy audit changes the per-item cost. When two or more services share the same site visit and setup time, the combined price is typically 10-15% lower than booking each separately.

Why the Boerne Climate Makes Air Sealing a First Step, Not an Optional Add-On

Boerne sits at roughly 1,400 feet elevation in Kendall County, which gives it a climate that most of Texas doesn’t deal with: genuinely cold winters and genuinely brutal summers. The Guadalupe River keeps afternoon humidity higher than you might expect for Hill Country, and that moisture interaction with an un-air-sealed attic floor creates a compounding problem that insulation alone cannot fix.

In the summer cooling season, hot attic air at 140-145 degrees doesn’t just radiate down through insulation – it actively infiltrates the living space through every gap around can lights, top plates, and chase walls. A blower-door test on a typical mid-2000s Boerne home before air sealing commonly reads between 3,800 and 5,500 CFM50 (cubic feet per minute at 50 pascals of pressure – the standard measure of whole-house air leakage). After a thorough attic air seal, it’s realistic to see that number drop to 2,000-3,000 CFM50 on the same home. That’s not a small change. It’s the difference between an HVAC system that runs in 20-minute cycles and one that runs in 12-minute cycles on a July afternoon.

In winter, the stack effect – warm air rising through the ceiling and escaping into the attic – pulls cold air in at the bottom of the house. Boerne sees enough nights below 28 degrees Fahrenheit that this matters for heating bills, not just comfort. Air sealing addresses the stack effect directly; adding more insulation depth without sealing first only slows the heat loss slightly and doesn’t stop the air movement at all.

This is why Envelope Insulation Co., operating under The Haven Standard since 2016, treats air sealing as a hard prerequisite rather than an upsell. We’ve done this work in neighborhoods throughout Boerne – Esperanza, Herff Ranch, The Dominion at Boerne, Balcones Creek, the Guadalupe Heights area – and the pattern is consistent: the homes with the highest energy bills and the most HVAC complaints are the ones where insulation was added over an un-air-sealed attic floor. Adding more R-value on top of a leaky ceiling is expensive and largely ineffective.

Boerne-Specific Considerations That Affect Your Quote

Kendall County doesn’t require a building permit for attic insulation upgrades or air sealing on an existing residence as of 2026, which keeps the administrative overhead off your bill. City of Boerne proper follows Kendall County permitting guidelines for work that doesn’t alter the structural envelope – air sealing and insulation fall in that category. If your project also involves replacing an attic HVAC system or adding a whole-house ventilation component, permit requirements change, but that’s a separate discussion from air sealing scope alone.

Utility rebates are worth asking about before you schedule. CPS Energy does not serve Boerne – the city’s electricity is primarily served by Bandera Electric Cooperative and Pedernales Electric Cooperative for outlying areas. Neither cooperative currently publishes a standing residential air sealing rebate program as of early 2026, but that can change. City of Boerne water and gas customers should check with their provider before the job is scheduled, not after, because rebates are almost always pre-approval programs.

Many Boerne homeowners asking about attic air sealing are also in the middle of evaluating their full building envelope – crawl space, wall insulation, and attic insulation together. The home page outlines the full scope of envelope services available so you can see how air sealing fits into a broader project if that’s what you’re working toward.

How to Save on Attic Air Sealing

Bundle the Work When It Makes Sense

The biggest legitimate way to reduce the per-service cost is to schedule air sealing at the same time as another attic project. If your existing insulation is below R-30 (Boerne’s climate zone – Climate Zone 3 under IECC 2021 – calls for R-38 to R-60 in attics), you’re likely scheduling insulation soon anyway. Doing air sealing first in the same visit, before insulation is added, saves the labor cost of moving insulation that’s already been installed. That sequence also produces a better result because the sealing is done on bare or near-bare decking, which gives the technician full access to every top plate and penetration.

Get the Blower-Door Baseline First

A pre-sealing blower-door test – a pressurization measurement that identifies, by location and magnitude, where air is escaping – tells the technician exactly where to spend time. Without it, you’re paying to seal everything uniformly, which wastes material and labor on penetrations that were already reasonably tight. Homes in Boerne’s newer planned communities like Herff Ranch often have tighter construction to begin with; a blower-door test confirms that before the crew spends two hours on penetrations that aren’t contributing meaningfully to the leakage rate.

Get a Written Price Before Any Work Starts

This is Haven Standard Clause 1, and it exists specifically to protect you from scope creep. If a contractor quotes a low number verbally and bills a higher number when the job is done, you have no recourse. A written scope with a flat price – delivered before anyone opens a can of foam – is the only way to make an apples-to-apples comparison between contractors. Envelope Insulation Co. provides this on every job, no exceptions.

Use the Free Second Opinion

If you’ve already received a written estimate from another contractor, bring it to us. Wes Okafor and the team will read it with you line by line – not to tear it apart, but to make sure the scope is complete and the price is reasonable for what’s being proposed. A second opinion on a $1,500 job that takes 20 minutes of conversation is worth doing. Call (830) 529-7780 to set that up.

Don’t Delay Until the HVAC Fails

The Boerne HVAC replacement market has a consistent pattern: homeowners replace an aging system, the new system struggles to maintain temperature because the attic is still leaking conditioned air at 4,500 CFM50, and then they call about insulation and air sealing as a second project six months later. Sealing the attic before an HVAC replacement – or as part of the same home improvement season – means the new system is sized and operating against an actual, sealed envelope. Air sealing first is cheaper than air sealing after you’ve already paid for equipment that’s now undersized for a leaky house.

What You Actually Receive When the Job Is Done

When Envelope Insulation Co. completes an attic air sealing project in Boerne, the technician doesn’t leave without providing a Documented Photo Record – photographs of conditions before work began, progress shots of each major penetration sealed, and final photos showing the completed work. On applicable jobs, a before-and-after blower-door reading is included so the CFM50 change is on paper, not just described verbally.

You also receive a written scope with a written warranty – the same document provided before work started, now marked complete. The 365-Day Done Right Promise applies: if something isn’t right within a year, we make it right. That’s a written commitment, not a verbal reassurance.

For a detailed look at the full service – what gets sealed, which materials are used, and how the documentation process works – the Attic Air Sealing in Boerne page covers it thoroughly.

FAQs – Attic Air Sealing Cost in Boerne

How much does attic air sealing cost in Boerne, TX?

Attic air sealing in Boerne typically costs between $850 and $2,400 depending on home size, number of penetrations, and whether existing insulation must be moved. Most homes in the 1,600-2,400 square foot range – which covers the majority of Boerne’s housing stock in areas like Esperanza and Herff Ranch – land between $1,200 and $1,700 for a complete air seal of the attic floor. A written price is provided before any work starts. Call (830) 529-7780 to schedule a free estimate at your address.

Is attic air sealing worth it in Boerne’s climate?

For most Boerne homes, yes – the payback period on attic air sealing runs 3-6 years based on typical energy savings, and the performance change is measurable. A blower-door test on a mid-2000s Boerne home before air sealing commonly reads 3,800-5,500 CFM50. After sealing, the same home typically reads 2,000-3,000 CFM50. That reduction translates directly to shorter HVAC run cycles during Boerne’s extended cooling season. Homes that already had air sealing done during original construction see a smaller but still meaningful improvement from addressing areas that were inadequately sealed the first time.

How long does attic air sealing take?

A standard air sealing job on a 1,600-2,400 square foot Boerne home takes 4-7 hours for a two-person crew. Homes with 60 or more can light penetrations, or homes where existing deep insulation must be moved and reset, can run 8-10 hours. The job is completed in a single visit in the large majority of cases. You’ll receive a time estimate along with the written price before the crew arrives.

Can I just add insulation without air sealing first?

You can, but it won’t produce the results you’re expecting. Adding insulation over an unsealed attic floor slows radiant heat transfer but does nothing to stop the air movement through gaps around can lights, top plates, and penetrations. In Boerne’s climate – where attic temperatures exceed 140 degrees in summer – the air movement through those gaps is a larger driver of cooling costs than the R-value of the insulation above them. Envelope Insulation Co. doesn’t install blown-in insulation over an unsealed attic floor; air sealing is completed first on every applicable job. Call (830) 529-7780 if you want a blower-door baseline before deciding on scope.

Does Boerne require a permit for attic air sealing?

No – as of 2026, Kendall County and the City of Boerne do not require a building permit for attic air sealing or insulation upgrades on an existing residential structure, provided the work doesn’t alter the structural envelope or involve new mechanical systems. This keeps permit fees off your project cost. If your air sealing project is part of a broader renovation that includes structural or mechanical changes, permit requirements may apply to those portions of the work separately.

Is it cheaper to do air sealing and insulation together?

Typically 10-15% cheaper per service when bundled into a single visit, because setup, travel, and access time are shared. For a 1,600-2,400 square foot Boerne home, air sealing plus blown-in insulation together usually runs $2,200-$3,800 – versus roughly $1,400-$1,700 for air sealing alone and $1,200-$2,000 for insulation alone if booked separately. The sequence matters regardless of bundling: air sealing first, insulation second. That order is non-negotiable on every Envelope Insulation Co. job.

Key Takeaways

• Attic air sealing in Boerne costs $850-$2,400 for most homes, with $1,200-$1,700 being the most common range for 1,600-2,400 sq ft houses.
• Home age, number of can light penetrations, attic access, and whether existing insulation must be moved are the main cost drivers.
• Boerne’s climate – hot summers with attic temps above 140 degrees, cold winter nights – makes air sealing one of the highest-return envelope improvements available.
• A written price is provided before any work starts, a Documented Photo Record is included when the crew leaves, and before-and-after blower-door readings are provided on applicable jobs.
• Bundling air sealing with insulation in a single visit typically saves 10-15% versus booking separately.
• Kendall County and City of Boerne don’t require a permit for air sealing on existing residences as of 2026.
• The 365-Day Done Right Promise applies to all completed work – in writing, not just verbally.

Schedule a Free Estimate in Boerne

If you want a price specific to your home – not a range from a webpage – Wes Okafor and the team at Envelope Insulation Co. provide free, no-obligation estimates with a written price before any work starts. We serve Boerne and the surrounding Kendall County area, including Fair Oaks Ranch, Comfort, and the Guadalupe Heights corridor. A live person answers the phone 24/7 – no voicemail loops, no callback windows measured in business days.

Call (830) 529-7780 to schedule your free estimate. Bring a competing quote if you have one – we’ll read it with you.

Written by Wes Okafor, Owner at Envelope Insulation Co. (operating as Topside Attic Insulation Boerne), serving Boerne, TX since 2016.

Pricing reflects the Boerne market as of 2026. Topside Attic Insulation Boerne offers free estimates – call (830) 529-7780.