Calculating Blown In Insulation Cost

With ever more focus on energy efficiency in the home, insulation is one area where the average home can make a significant difference. Whether your reasons are financial, environmental or purely for comfort, blown in insulation will go a very long way to achieve those goals. On this site we will guide you through the planning process and advise you on how much insulating material will be required to get your project completed.

For most people the main question will be about the blown in insulation cost and this site will provide you with a guide to estimating those costs. Also keep in mind that you can claim a Federal Energy Efficiency Tax Credit up to $500, which can go a long way towards paying for the job.

The most commonly used material for the blow-in method is fiberglass, so the first table will focus on this material. Ultimately, the cost will come down to the amount of insulation you want to have blown in. The more insulated you want your home to be, the more material will be needed, and the more labor time will be required to get the job done.

Blown-In Attic Insulation Costs:

​The following chart will serve as a blown in insulating calculator that will also help you plan the job by giving you a good indication of the depth and time involved.

R-Value Bags* Per 1,000 Sq. Ft. Material Cost** Installed Thickness Inches Hours of Labor***
R 30 15 $495 10.25 4
R-38 20 $660 13 5
R-44 23 $759 14.75 6
R-49 26 $858 16.5 7
R-60 32 $1,056 20 8

* based on average bag weight of 28.5 lbs.

** Based on Home Depot price of $33 per bag

*** this is dependent on the machinery used

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R-30 is the minimum recommended amount for attics, in order to achieve more thermal efficiency. At a current price at Home Depot of about $33 per bag, the material costs will be a minimum of $495, plus 4 hours of labor. Blowing material into an attic is a relatively straightforward DIY attic insulation job. All you will have to do is rent the machine and get one other person to help you out by keeping the machine filled.

So for a DIY job on a 1,000 sq. ft. attic you can expect to pay:

  • Materials: $500 to $1,100
  • Machine rental: $100
  • Total: $600 to $1,200

While this is a rough blown in insulation calculator it will prove pretty accurate, and the great thing is that you can add more material at a later stage if your budget is limited.

Check out our recommended local Insulation Specialists:
Spray Foam Insulation Dallas


Blown-In Walls/Floors Insulator Costs:

DIY Attic Insulator

DIY Attic Insulation

Wall and floor insulation is considerably more complex than an attic project, and requires the drilling of holes in precise locations of the walls or floors. Therefore it may be advisable to hire a professional for the job, if you are not comfortable with doing the job yourself.

You will notice in the below table that the maximum achievable r-value is a lot lower than in the attic table above. The reason for this is that the cavity space in walls is quite limited, whereas an unused attic space has room for a lot of material to be piled up.

R-Value Bags* Per 1,000 Sq. Ft. Material Cost** Installed Thickness Inches Hours of Labor***
R 13 13 $429 3.5 20
R-15 15 $495 3.5 23
R-21 21 $693 5.5 27
R-24 29 $957 5.5 30

* based on average bag weight of 28.5 lbs.

** Based on Home Depot price of $33 per bag

*** this is dependent on the machinery used

So for a DIY job on a 1,000 sq. ft. wall you can expect to pay:

  • Materials: $430 to $960
  • Machine rental: $100
  • Total: $530 to $1,060

As you can see, the amount of time it will take to prepare the walls and floors, and then pump in the material is quite high, and for a one person DIY job will take several days. Also be aware of the fact that it is quite tricky to make sure that each stud bay is properly filled from top to bottom. This may be a job best left to professionals, as it could end up costing you in the long run.

Costs for labor vary extremely from one end of the country to the other, but you can expect to pay anywhere from $40 to $70 per hour. This does make wall projects considerably more expensive than the attic equivalent. Taking an r-13 job for 1,000 sp. ft. you would be looking at:

  • Materials: $430
  • Labor: $800 to $1,400
  • Total: $1,230 to $1,830

Blown in wall insulation cost is considerably higher than the attic equivalent, but this should not put you off doing it.

Blown In Material Types

When it comes to blown-in materials there are three common materials:

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Fiberglass is by far the most commonly used material and is generally speaking the least expensive to use for insulation. The great advantage with it is that once it has been pumped into a cavity or the attic, it does not settle by the effects of gravity. This means that it does not lose any of its insulating properties over time.

blown in insulation calculator

Cellulose is a more natural material usually made from recycled paper and/or cardboard. The material is also treated to make it fire resistant and resistant to moisture and mold. Many people prefer using natural and recycled materials for ecological reasons, but keep in mind that it will generally cost more than the equivalent project using fiberglass.

Finally, spray in foam is one of the most effective materials of these blown in insulating types, due to the fact that once sprayed it expands and completely fills a targeted area. However, it is very expensive material to use, and would generally be prohibitive to use for attic or wall insulation. Where it does come in handy is for all areas around openings to the outside, e.g. around vents and door/window fittings.​

3 Major Benefits of Insulating

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Insulating your home has three main benefits that should give everyone reason to get the job done and justify the blown insulation cost:

  • Positive environmental impact of using less energy
  • Positive financial impact of using less energy
  • Increased levels of comfort in the home

For some people the main reason for insulating a home is down to having a positive impact by reducing CO2 emissions. This is definitely something these projects will do, as the average home, when properly insulated can save up to 30% on energy consumption.

blow in insulation

​This saving on energy use also has a huge impact on energy bills, and probably makes this one of the biggest benefits. With oil prices rising and utility companies increasing their charges on a regular basis, the financial benefit of properly insulating a home will only increase in the years to come.

And finally, whether you predominantly heat or cool your home, it will be a lot more comfortable when there is less temperature change between indoors and outdoors. This results is a much more even and stable temperature, that is not only easier to achieve, but also easier to maintain.

Insulating R Value

R-value of insulation is a measure of thermal resistance used by the construction industry. The higher this value the more insulation there is. Generally speaking the same r-value can be achieved with different materials, but dependent on the efficiency of the material more inches of it will be required. In tight spaces, like cavity walls and under floors it makes sense to use more efficient and expensive materials, while in most attics cheaper material can be used with greater thickness to save money. Ultimately the r-value you choose will dictate the blown in insulation cost. You should always work out how much material you need in order to achieve a certain insulating r value, as this will give you a good indication of costs.

Don’t forget to claim your Federal Energy Efficiency Tax Credit once you have started your project.

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