(770) 925-2188

Physical address:
4230 Lawrenceville Hwy
Lilburn, ​Georgia.

Spray foam vs. fiberglass insulation cost comparison!

Spray foam and fiberglass are two popular insulation choices for barndominiums. Spray foam usually costs twice/thrice of the fiberglass insulation cost. We will break down the cost parameters and make an in-depth comparison between both choices.

How much does spray foam and fiberglass insulation cost for a barndominium?

In a nutshell, spray foam insulation usually costs around USD 0.65 to USD 2.00 per square foot with an inch of thickness. Whereas the fiberglass insulation costs around USD 0.45 to USD 1.00.

*The closed-cell spray foam costs high as it offers better R-value compared to the open-cell spray foam.

**The batt insulation (a fixed form of fiberglass) costs low compared to the blown-in fiberglass.

Closed-cell foam insulation is denser than open-cell foam insulation, leading to its higher R-value – typically ranging from R-6 to 7 per inch of thickness. This superior insulation capability is why closed-cell foam costs between $1.00 and $2.00 per square foot compared to the $0.65 to $0.75 range for open-cell foam, which typically has an R-value from R-3.5 to 3.6 per inch.

The exceptional energy efficiency of closed-cell foam may result in lower energy costs over time, potentially offsetting the higher initial cost.

In addition, closed-cell foam provides added structural integrity and improved moisture resistance capabilities, vital in areas prone to dampness or requiring extra strength. These added benefits justify its higher cost.

Blown-in insulation, with an R-value of around R-2.2 to 2.7 per inch, is more efficient at filling gaps compared to batt insulation, which has an R-value of about R-2.9 to 3.8 per inch.

Blown-in insulation’s method of installation results in its price of up to $1.00 per square foot compared to the $0.45 to $0.65 range for batt fiberglass insulation. Typically batt insulation comes at a standard size which limits the capacity to cover tiny areas.

Alternatively, the comprehensive coverage of blown-in insulation reduces air leakage more effectively, offering higher energy efficiency and contributing to significant long-term savings on energy costs.

Spray foam insulation advantage

Let’s estimate the insulation cost

Let’s consider a hypothetical barndominium with a total wall area of 2000 square feet and a standard wall depth of 3 inches (roughly 0.25 feet).

At $1 to $2 per square foot, the total cost for closed-cell spray foam insulation would range from 2000 * $1 = $2000 to 2000 * $2 = $4000. Whereas the open-cell spray foam would cost around $1500 using the same calculation method.

With a cost range of $0.45 to $0.65 per square foot, using batt insulation would cost between 2000 * $0.45 = $900 and 2000 * $0.65 = $1300. And, using the blown-in fiberglass, the same barndo would cost around $2000 or slightly higher than that.

The cost of insulating your barndominium can significantly vary depending on which areas of the building you’re insulating. Each section has unique requirements and challenges that can influence the overall cost.

The basement can be one of the more challenging areas to insulate due to moisture issues and irregular structures. Therefore, the cost is a bit higher, ranging approximately from $1.70 to $2.90 per square foot, a slight increase of about 10-15% from the given figures.

The attic is vital to insulate since heat rises and can escape through here, leading to significant energy losses. Insulating an attic can cost roughly between $1,725 to $6,900, depending on which insulation are you using.

Insulating the roof is critical in areas with heavy snowfall to prevent heat loss and ice dam formation. Therefore, the cost can range between $1,725 to $5,175.

Again, these are estimates, and actual costs may vary due to factors such as labor, installation equipment, and regional price differences.

Pro tip: You can use closed-cell spray foam for the side walls and open-cell for the indoors. It will significantly reduce the overall cost of insulating.

Tips to optimize the insulation cost

First, you need to properly assess your needs. You need to be aware that different insulation types have varying R-values and respective benefits.

In summary, the insulation cost optimization tips are:

  • Getting multiple offers
  • Trying to get additional service at free of cost
  • Conducting an energy audit before starting
  • Trying DIY approach

If your barndominium is in a region with extreme temperatures, it might be more cost-effective long-term to opt for insulation with a higher R-value and greater thermal efficiency (such as closed-cell spray foam).

Besides, you optimize the cost by mixing the insulation (depending on the climate and local regulations). For instance, one of our readers used closed-cell spray foal in outdoor walls and applied the open-cell insulation indoors.

You may consult with a professional before making any decision. They can conduct an energy audit, even at free of cost (provided by the vendors sometimes), and make specific recommendations based on your building’s needs. This could result in substantial savings over time.

Consider Getting quotes from multiple installers. Prices can vary significantly between providers, so shopping around may help you find a better deal. If you cannot get a deal at a low cost, try to get something else from the same vendor such as arranging an energy audit after finishing the work or an extended warranty period.

If you’re handy and your building codes allow it, consider installing the insulation yourself. However, we do not recommend a DIY approach for the spray foam insulation as they contain chemicals and uncontrolled spray may cause damage to neighboring parts of your barndominium.

Spray foam vs. fiberglass insulation (The differences)

Here’s a side-by-side comparison:

Spray Foam Insulation Fiberglass Insulation
Material Polyurethane-based foam Glass fibers compressed into a batt
Installation Spray application, expands to fill spaces Cut and fit into place, doesn't expand
Types Open-cell (lower density) and closed-cell (higher density) Batt (pre-cut panels) and blown-in (loose-fill)
R-Value Open-cell: Approx. 3.5-3.6 per inch Closed-cell: Approx. 6-7 per inch Batt: Approx. 2.9-3.8 per inch Blown-in: Approx. 2.2-2.7 per inch
Cost Open-cell: $0.65-$0.75 per sq ft per inch Closed-cell: $1-$2 per sq ft per inch Batt: $0.45-$0.65 per sq ft per inch Blown-in: Up to $1 per sq ft per inch
Moisture Barrier Closed-cell foam resists water and moisture Fiberglass does not resist water; can absorb moisture
Air Barrier Both open and closed-cell foam can block air Fiberglass does not block air
Sound Dampening Good sound dampening, especially open-cell Fair sound dampening
Environmental Impact Lower R-value varieties use HFCs, which have high Global Warming Potential (GWP), but there are low-GWP alternatives Glass fibers are made from sand, an abundant resource, but manufacturing process requires a lot of energy
Health Risks Proper safety gear is needed during installation to avoid respiratory and skin irritation Can cause skin, eye, and respiratory irritation if not properly handled

Difference in longevity

Spray foam insulation, especially closed-cell foam, tends to have a longer lifespan and superior durability compared to fiberglass. Spray foam expands to fill gaps and does not settle or sag over time, maintaining its insulating ability for many years. Its high R-value ensures effective insulation for a long duration, leading to consistent energy savings. On the other hand, fiberglass insulation can settle over time, reducing its effectiveness, and may need to be topped up or replaced periodically.

Impact on future home value

Insulating your home properly can significantly increase its future value. While precise figures can vary based on location, housing market, and other factors, upgrading insulation can increase home value by up to 1% per each point increase in HERS Index Score (a measure of energy efficiency). Given its higher R-value and durability, spray foam insulation may result in a larger increase in home value compared to fiberglass.

Family friendliness is a concern

From a health standpoint, both types of insulation require proper installation and safety precautions to prevent skin, eye, or respiratory irritation. Once installed, they should not pose health risks.

However, spray foam has superior air sealing properties, which can reduce allergens and improve indoor air quality, potentially benefitting family members, especially those with allergies or respiratory conditions mainly because it offers greatest moisture barrier.

Weather resistance

Spray foam, particularly closed-cell foam, offers superior resistance to weather due to its water-repelling properties and high R-value, making it effective in both hot and cold climates. It’s especially useful in areas prone to moisture issues or extreme temperatures.

Fiberglass insulation, while providing fair thermal resistance, does not offer the same level of moisture resistance, which can lead to issues in damp climates or basements.


There’s no good or bad in choosing insulation from spray foam and fiberglass. Depending on your local guideline, level of protection required and the future energy impact you need to choose the right insulation for your barndominium.

Brian Cooper
Brian Cooper

I'm Brian, an architectural engineer from the University of Texas

Writing about barndominium is my passion. I try to bring informative and technical contents on barndominium so that the entire sourcing and construction process seems easy.

As an architectural engineer, I do have expertise of designing and building using prefabricated steel structures. Moreover, I am connected with 500+ prefabricated steel structure experts that helps me to gather and prepare the relevant information for your help.

I have experience of 250+ barndominium contrustion of which 75% are built with metal structure. Moreover, I am a trained energy audit professional, and with that specialization I can help you to bring your barndo's energy consumption at minimum level.

I hope you like my write-ups which is my greatest inspiration.

Articles: 44

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.