Insulation Cost

A brief analysis of what the average insulation cost might be for any size remodeling job, large or small.

Depending on the age and price range of the house you’re remodeling, you can either go with standard batt-type fiberglass, or a type that is becoming increasingly popular these days, spray-on foam. This type of insulation is especially popular among home remodelers and house flippers of older homes, particularly those built before 1940.

The reason foam is such a viable option, is the relative ease with which you can apply (spray) the foam to wherever you need to, without the cutting and stapling of conventional batt-type insulation. Excellent for working with older structures that were built with little or no framing standards as we know them today.

man spraying insulation in home

The framing techniques used back then, although generally solid, were still somewhat uneven and random. When you reach the point at where you’re ready to insulate, you’ll find it can be a real headache to constantly size and cut pieces to fit a multitude of irregular openings found throughout.

Since lathe (wood supports for plaster) and plaster covered any unevenly framed walls, there was no need to be exactly flush, in terms of the integrity of the wall itself. Unlike today’s modern housing, the finish craftsmen didn’t have to worry about adding insulation before finishing the wall with plaster.

Once your demolition is complete, and all the rough mechanical installation has been completed and inspected, you’re ready for the insulation to be installed.

Two of the More Common Types


If remodeling an older house, you’ll notice that the studs were seemingly placed somewhat haphazardly and at irregular intervals. This will create a headache when trying to install said fiberglass (batt) materials.

You might have a 13 inch wide gap followed by a 27 inch wide gap to fill. That calls for a lot of cutting and stapling. This is not to say that fiberglass is not a suitable insulator – it is. It just requires more work to hang (especially in an older remodel) if you do it yourself.

If you are a do-it-yourselfer, insulation cost will be about 25¢ per sq. ft. of open cavity to insulate, plus your total time. This can be easily accomplished with material purchased off the shelf at any of the major home improvement stores.

For much larger projects, consider hiring a professional contractor and save yourself a lot of work and frustration, not to mention the the fact that handling fiberglass material can be very uncomfortable. Insulation cost would be in the neighborhood of about 45¢ to 75¢ per sq. ft. of space to insulate when using an insulation contractor.

Spray-On Foam

spray-on foam insulation

When spray foam is applied correctly, it can cover and completely enclose any crevice or opening in any type of wall or ceiling framing to accomodate old houses, as well as newer ones. That’s why it is becoming so popular. It simply makes an older home seem “tighter”, and more solid.

Remember the old styrofoam coolers people used back in the day? Well, in a way, that’s how airtight the house might seem to be. It’s a great selling point to prospective home-owners because not only of the aforementioned air-tight quality, but the huge savings on the yearly energy bill. As far as insulation cost goes, it would take little time for the stuff to actually pay for itself.

The only drawback for this type of application, is the price. You would have to pay probably between two to three times the rate for normal installation of fiberglass (batt-type).

And one more thing. Always hire an experienced contractor to apply this type of product. It requires skill and stamina to put this stuff exactly where it needs to go (i.e.: not on the studs or joists), and to do it safely. It’s expensive, but as we said before, definitely worth it if you’re flipping an older home in a pricey neighborhood whereupon it becomes an attractive selling point.

And just in case you’re wanting to use fiberglass insulation, but you’re not sure about the correct thickness to use, the following info might help a little …

What Exactly Is R – Value?

Technically speaking, it is something like this:

R value = Temperature Difference x Area x Time/ Heat Loss

In simple terms, it is a measurement of the amount of resistance presented by any type of insulation against heat loss. The less thickness of insulation present, the faster the heat will be lost through the wall. This would represent a lower R value. So, obviously, the higher the R value, the better the resistance to any heat loss.

Minimum R – Value Guide

  • Ceiling/Attic – R45
  • Walls – R19
  • Floors – R25
  • Basement walls – R11
  • Slab – R4 -R5


fire-retardant spray foam

Fill those little skinny openings and crevices that conventional fiberglass or spray-on industrial equipment just won’t reach by using a can of spray foam orange-colored fire retardant) to fill the cracks.

You’ll find it in the bigger stores such as Lowe’s or Home Depot in the section where you’ll find insulation and lumber.It’s a minor insulation cost, but well worth it.