Trusted Home Energy Audit for San Marcos Homeowners
A San Marcos Home Energy Audit typically costs $350-$850 depending on home size and test scope, and most audits are scheduled within 48 hours with same-day reporting on findings. We use a blower door, thermal camera, and duct blaster to measure exactly where your conditioned air is escaping and what it is costing you on your electric bill.
We’ve sealed and insulated over 9,000 homes since 2016, every one starting with a written price and ending with a documented record. In Kyle and San Marcos, we regularly see homes in the Blanco River watershed struggle with humidity-driven energy loss - attics that test tight visually but leak through top plates and can light housings, or duct systems in crawl spaces pulling in warm, moist air from outside. Our audits are built to find those specific leaks, not to sell you insulation you don’t need. Call (737) 337-8049 to schedule. A live person answers 24/7.
What Our Home Energy Audit Service Includes
Blower Door Test
A blower door test is a pressurization reading that shows, in one number, how much air your building envelope is losing. We mount a calibrated fan in an exterior door, depressurize the house to 50 Pascals, and measure airflow in CFM50 - cubic feet per minute at that standard pressure. In San Marcos, we regularly see pre-audit readings of 3,500-5,500 CFM50 in 1980s-2000s construction; after proper air sealing, we expect 35-50% reduction. You receive the before-and-after number in writing, with a photo of the manometer display, so you can verify the result yourself.

Thermal Imaging Inspection
We use a FLIR thermal camera during the blower door test to visualize temperature differences that indicate missing insulation, air leaks, or moisture intrusion. In San Marcos homes near the river corridor, we often find thermal bypasses at rim joists and kneewalls that are invisible to the eye but show clearly as blue streaks on the camera. The images are included in your Documented Photo Record, timestamped and annotated with the room location and the R-value we measured at that spot.

Insulation Inspection
We measure existing insulation depth and density, identify compression or displacement from wiring or plumbing, and check for signs of rodent activity or water staining that compromise thermal performance. In San Marcos, we frequently find fiberglass batts installed upside-down with the paper vapor barrier facing down into the attic - a common error in 1990s builds that traps moisture against the drywall. We document each bay with photos and note whether the existing material can be supplemented or needs full removal and replacement.

Duct Leakage Test
A duct blaster test pressurizes your duct system to measure leakage to outside the conditioned envelope, reported as CFM25 or as a percentage of system airflow. San Marcos homes with ducts in vented attics often test at 25-40% leakage, meaning a quarter to nearly half the air you paid to cool is dumping into the attic before it reaches the rooms. We seal accessible leaks with mastic and metal tape, then retest to confirm the reduction. The final leakage rate is recorded in your written report alongside the before number.

What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Brands We Service for Home Energy Audit

We work with insulation and building envelope materials from Johns Manville, Knauf, and Rockwool on a routine basis. Our crews are trained to identify these products in existing installations and understand their specific performance characteristics - for example, Johns Manville batts have a distinct color-coding system for R-value that we check against your local code requirements, and Rockwool’s higher density makes it easier to spot gaps where air is moving through the cavity. We’ve audited homes with every combination of original and retrofitted materials, so we know what to look for when the thermal camera suggests a problem.
Whether your home was built with CertainTeed, Owens Corning, or a mix of brands from multiple renovation phases, we can assess what is there now and what should stay or go. Our material recommendations are based on blower-door and duct-blaster data, not brand preference. We source from eight major manufacturers including Icynene and GreenFiber, so we are never locked into pushing a proprietary product.
Before
AfterSigns You Need Home Energy Audit Right Now
- Your upstairs rooms run 8-12 degrees warmer than downstairs in summer. This is not normal in a properly sealed and insulated home. In San Marcos, we trace this pattern most often to duct leakage in the attic and unsealed top plates that let hot attic air press down into the wall cavities. The audit will measure both and show you which is the bigger factor.
- Your electric bill in August exceeds $300 for a home under 2,500 square feet. At CPS Energy’s current residential rates, that level of consumption points to either envelope leakage or duct losses that are forcing your HVAC to run continuously. We compare your usage against square footage and construction year to flag outliers.
- You feel drafts near outlets, baseboards, or can lights even when windows are closed. These are telltale signs of air bypasses at the thermal boundary. Our blower door test quantifies the total leakage, and the thermal camera shows us exactly which penetrations are the worst offenders so we can prioritize the fixes.
- Your insulation was installed more than 15 years ago or you have had rodent activity in the attic. Compressed, displaced, or contaminated insulation performs at a fraction of its rated R-value. We measure what is actually there and photograph any areas where removal is the only proper option.
- You are considering solar panels or a new HVAC system. Both investments perform poorly if the building envelope leaks. We have audited San Marcos homes where a $15,000 solar array was undersized because the roof leaked air, and others where a new 16-SEER unit could not reach its efficiency rating due to 35% duct leakage. Fix the envelope first. The numbers will show you why.
Our Home Energy Audit Process - Step by Step

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Schedule and confirm. Call (737) 337-8049 or text us. A live person answers 24/7. We confirm your address in San Marcos, home size and age, and any specific concerns. You receive a text with your technician’s name and photo when they are en route.
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Written price before any work starts. Under Haven Standard Clause 1, we deliver a flat price and written scope before the crew enters your home. The audit price covers all four diagnostic tests, the Documented Photo Record, and the written findings report. No surprises, no add-ons.
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Diagnostic testing. We perform the blower door test, thermal imaging scan, insulation inspection, and duct leakage test in sequence. The full process takes 2.5-4 hours depending on home size. You are welcome to follow the technician and see the thermal camera display in real time.
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Review findings on site. Before we leave, we walk you through the photos, the blower-door number, the duct leakage percentage, and our prioritized recommendations. You receive a printed summary and a digital copy within 24 hours.
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Written scope for any follow-up work. If air sealing, insulation, or duct repair is warranted, we deliver a separate written price for that work with no obligation. The audit report is yours regardless of whether you hire us for the repairs. Under our 365-Day Done Right Promise, any work we perform is backed by a written warranty.
How Much Does Home Energy Audit Cost in San Marcos?
A typical home energy audit for a 1,200-2,000 square foot home in San Marcos runs $350-$550; see how much Home Energy Audit costs for full pricing details. For homes between 2,000 and 3,500 square feet, or those with multiple HVAC systems, the audit typically ranges from $550-$850. The variance depends on three factors: square footage (more area = more thermal scan time), number of duct systems (each requires a separate duct blaster test), and accessibility of attics or crawl spaces.
What affects the price beyond base size? Homes with conditioned space over a vented crawl space add roughly 45-60 minutes to the inspection. Multiple attic accesses, detached garages with shared ductwork, or post-renovation additions with unknown construction details can extend the diagnostic time. We price these variables into the written scope upfront, not as add-ons after we arrive.
How to avoid overpaying: Some San Marcos homeowners have paid $200-$300 for a “free” audit that was actually a lead-generation appointment with a 20-minute walkthrough and a sales pitch for $8,000 in insulation. A legitimate blower door test alone requires 45 minutes of setup, testing, and teardown. If the auditor does not use a blower door, a duct blaster, and a thermal camera, you are not getting an audit. You are getting a sales call.
What is included in our estimate: The full diagnostic suite, the Documented Photo Record with timestamped thermal images, the written findings report with prioritized recommendations, and a separate written price for any repair work if you choose to proceed. Estimates are free and carry no obligation. Call (737) 337-8049 for a written price before any work starts.
Home Energy Audit Near San Marcos - Our Service Area

We perform home energy audits throughout Hays County and into Caldwell and Travis counties, with typical drive times of 15-35 minutes to Kyle, Redwood, Buda, Lockhart, and the Austin metro fringe including Shady Hollow and Lost Creek. For homes in Bastrop, Lago Vista, or Lakeway, we schedule audits to minimize travel overhead and keep your appointment window tight. Response time in San Marcos proper is typically next-day or within 48 hours; outlying areas are usually within 72 hours. Call (737) 337-8049 to confirm availability for your address.
Serving San Marcos, TX - Our Local Coverage Area
We’re based in the San Marcos area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions - Home Energy Audit in San Marcos

A home energy audit is a diagnostic inspection that measures how much conditioned air your home loses through leaks, insulation gaps, and duct defects, and identifies the specific locations and cost of those losses. Our audit combines four tests - blower door, thermal imaging, insulation inspection, and duct leakage testing - to build a complete picture of your envelope performance. You receive a written report with photos, numerical results, and prioritized repair recommendations. Call (737) 337-8049 to schedule; estimates are free.
Most audits take 2.5-4 hours from arrival to departure, depending on home size, number of HVAC systems, and attic or crawl space accessibility. A 1,500 square foot single-story home in San Marcos with one system and a single attic access typically tests in under three hours. We do not rush the blower door or duct blaster setup; calibration takes time, and accurate readings depend on it. You receive preliminary findings before we leave, with the full digital report within 24 hours.
Home energy audits in San Marcos and nearby Lockhart typically range from $350 for smaller homes to $850 for larger or more complex properties, with most falling in the $400-$650 range. The price is set before we arrive, in writing, with no add-ons for standard diagnostic time. If your home has multiple duct systems, a vented crawl space, or other complicating factors, we note these during scheduling and price them into the original scope. Call (737) 337-8049 for a written price specific to your home.
Yes. We regularly audit homes with Rockwool, Knauf, Johns Manville, and all major insulation brands, and we know the installation quirks and performance characteristics of each. Rockwool’s density makes it less prone to wind washing in vented attics but harder to inspect for gaps; Knauf’s EcoBatt uses a plant-based binder that performs well in our humidity but requires careful vapor barrier placement. We assess what is actually installed, not what the label claims. Call (737) 337-8049 to schedule an audit of any insulation type.
We do not treat energy audits as emergency services, but we do maintain next-day and 48-hour availability in San Marcos for homeowners facing urgent decisions - a failing HVAC system, a home sale contingency, or a solar installer pressuring for a quick contract. A live person answers our line 24/7, and we will tell you honestly whether we can meet your timeline. If your situation is truly urgent, call (737) 337-8049 and we will find the earliest slot that allows for proper diagnostic time.
The audit itself is a diagnostic service with documented deliverables - photos, readings, and a written report - so it carries our standard 365-Day Done Right Promise: if any test was performed incorrectly or the report contains an error we made, we return and retest at no charge. Any repair work you hire us to perform after the audit is also covered by the 365-Day Done Right Promise and a written warranty delivered before work begins. Haven Standard: Have it in writing.
Close all windows and exterior doors at least two hours before we arrive, and avoid running exhaust fans or the clothes dryer during that window. We need the house in its normal “closed up” state for the blower door test to measure real-world leakage. If you have recent electric bills, gather 12 months if possible; we use them to correlate consumption patterns with our findings. Pets should be secured, and attic or crawl space access points cleared. Call (737) 337-8049 when you schedule and we will send a preparation checklist by text.
Schedule Your Home Energy Audit Service in San Marcos Today
Call (737) 337-8049 to schedule your home energy audit in San Marcos. A live person answers 24/7, and we will deliver a written price before any work starts. Your audit includes the full diagnostic suite, a Documented Photo Record, and a written findings report with prioritized recommendations. No obligation, no upsell pressure, and every finding backed by a number you can verify yourself.
Written by Wes Okafor, Owner at Topside Attic Insulation San Marcos, serving San Marcos since 2016.