Fiberglass Insulation Cost

Fiberglass Insulation Cost

Fiberglass is far and away the most popular choice for attic insulation material, and there’s a whole laundry list of reasons why. Aside from it being significantly more effective in energy savings when comparing it to foam insulation, the most convincing argument for choosing fiberglass is a simple one: it’s a fantastic product that you can buy for an irresistibly inexpensive price.

But just how inexpensive exactly? Like all insulation materials, fiberglass doesn’t come with a “one size fits all” price tag. There are several factors that go into the final cost of attic insulation installation with fiberglass. Read on for everything you need to know about how much money you can expect to spend on fiberglass insulation.

The Two Kinds of Fiberglass Insulation

Fiberglass insulation comes in two varieties:

  • Batts – These are the large blankets featuring long, puffy strands of fiberglass held together by an adhesive vapor barrier like reflective foil or paper. Because insulation batts are specially designed to be the same length as the standard distance between joists in your average attic, installation tends to be a breeze. You simply unroll them and tack them up where needed.

For attics that have HVAC units/piping/other awkward obstacles in the way, however, batt installation is a more complicated endeavor that requires the installer to cut them to an exact size and shape to fit the attic space properly.

  • Loose-fill – This type of fiberglass comes in chunks that can be purchased by the bagful. An installer will use a large blowing machine to spread this loose-fill material throughout your attic space as needed. For homeowners living in older homes with attics that have multiple obstructions on the floors and walls, loose-fill tends to be the fiberglass attic insulation choice.

Because fiberglass batts are considerably more popular among American homeowners than their loose-fill brethren, this article will focus on how the cost of batt insulation is determined.

Factor #1: The R-value of Fiberglass

The thermal quality of an insulator is referred to as its “R-value.” Simply put, the higher the R-value of a given insulator, the more effective it will be at resisting temperature transfer and, naturally, the higher the cost.

An insulation material’s R-value is primarily based on its thickness and density. Both of these qualities vary immensely with fiberglass, which means the price does too.

Factor #2: The R-value You Need in Your Attic

R-value is used to describe the thermal capability of not only insulation material but also a room as a whole.

Based on regional climate, each American state suggests—or in some cases, mandates—the minimum R-value that an attic must maintain. You can check out this helpful chart created by the US Department of Energy for an in-depth look at recommended attic R-values by region throughout the country, but the basic idea is as follows:

  • Homeowners living in perpetually balmy regions like southern California should shoot for an R-value of R30
  • Homeowners residing in frigid climates with brutal winters should maintain at least an R49, and perhaps even aim for as high as R60
  • Everyone else’s attic should have an R-value somewhere between R38 and R49

An attic’s R-value is calculated simply by multiplying the R-value of the insulation material you choose by the total amount in square feet of material installed. This means that, in the same way, a hefty winter jacket will cost more than a basic cotton t-shirt, attics that require higher R-values will result in you spending more money on insulation material.

Factor #3: Installation

If you’re intent on making the insulation of your attic a DIY insulation project, the factors that affect the cost of your fiberglass batts end there. But if you’d rather put the installation in the hands of a professional (which we highly recommend), that will add a few extra hundred dollars or so to the final invoice.

Though batts are the easiest insulator to install on your own, the DIY route leaves you prone to common amateur mistakes like:

  • Inadvertently tearing a corner of the batt
  • Cutting the batt to too short a size
  • Leaving a batt to be too long

Each of the above mistakes allows air to escape through any voids, which results in you throwing money out the window on your utility bill down the road. Shelling out the extra dough to a pro today will allow you to reap the benefits of fiberglass insulation and save hundreds, perhaps even thousands of dollars in heating and cooling costs in the long run. Energy efficiency is definitely not a benefit you want to miss out on by simply not installing your insulation correctly, which is why using professional will be your best bet.

Count on Attic Construction for Your Fiberglass Batt Installation

At Attic Construction, we pride ourselves on bringing you outstanding, expert service and the invaluable peace of mind that comes with knowing that your fiberglass insulation installation will get done correctly at the most competitive rates out there.

Contact us for a free quote today!


1) “Recommended Home Insulation R-Values” by the US Department of Energy

2) “How Much Does it Cost to Insulate a House?” by editorial staff at Home Advisor

3) “Everything You Need to Know About Insulation’s R-Value” by editorial staff at Today’s Homeowner with Danny Lipford

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