How Much Does It Cost to Insulate a Single Room?
Insulation helps fill up cracks and cavities in your walls and ceilings, which helps stop thermal transfer. This makes your home more energy efficient and the rooms within it more comfortable and easier to heat and cool. While insulation is easiest to add to new construction, it is possible to add it to an existing room as well.
Insulating a room costs on average $650 to $1,000, with the average homeowner spending around $825 on adding blown-in insulation to existing walls and ceiling in a 10’x10’ room.
| Insulating a room costs | |
|---|---|
| National average cost | $825 |
| Average range | $650 - $1,000 |
| Minimum cost | $200 |
| Maximum cost | $3,000 |
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Room Insulation Cost by Project Range
Reasons to Insulate a Room
If your home was built prior to the 1940s, it likely doesn’t contain any insulation inside the walls, and if it was built after that, but prior to the last 10 years, what insulation you do have may not be adequate. Insulation can also settle or deteriorate over time, and can be disturbed by pests or workmen, which can make it less effective.
Insulating a room means that less energy will be transferred through the walls and ceiling. This means that when you heat or cool this room, it will take less energy, because some of that heated or cooled air won’t be escaping through your walls. It also makes the room more comfortable to be in. So, if you have a room that tends to be very cold in the winter or very hot in the summer, or that seems difficult to heat and cool efficiently, then adding insulation can help.
Insulation can help reduce sounds coming into or leaving the room as well. If the room echoes or seems loud, adding insulation can help reduce these issues, making it more quiet as well as more comfortable.
Cost Factors
There are a lot of factors that play a role in the final cost of insulating a room. The size of the room is one of the biggest determining factors, as most insulation is sold and installed by the square foot, so larger rooms will cost more to insulate.
The type of insulation will also play a role. Some insulations will cost more than others. Some insulation will also require you to open up the walls to install them, while others can be added through small holes cut into the wall. Cutting and patching a hole ($20 - $30 per hole) will cost considerably less than removing and replacing the drywall ($1,500 - $2,000). If you’re in the middle of a renovation, you may be able to insulate at the same time using a less expensive method, while adding insulation to existing walls will always cost more, even if you don’t replace the drywall.
In addition, when walls are opened, you may discover that there is mold, old insulation that may contain asbestos 1, or you may discover that other repairs are required. Any of these instances will impact the total cost of the job.
R-value
When insulating, you need to pay attention to the R-value of the material you’re installing. R-value refers to how well the material resists the transfer of energy. Higher R-values mean better insulating properties, while lower R-values mean fewer insulating properties. Typically, R-value can be increased by increasing the thickness or the amount of insulation, but different insulations can also have different R-values.
The R-value you want to have in your home will be determined largely by where you live. The country is divided into zones, with the hottest, southern-most states in zone 1 and the northern states in zone 7. Each has a suggested R-value range for walls, and types of insulation to consider.
| Zone | Suggested R value | Insulation to consider |
|---|---|---|
| 1 | R13 - R21 Walls R13 Floors and Ceiling R30 - R39 Attic | Fiberglass batts Fiberglass blown in |
| 2 | R13 - R21 Walls R13 Floors and Ceiling R30 - R39 Attic | Fiberglass batts Fiberglass blown in |
| 3 | R13 - R21 Walls R25 Floors and Ceiling R30 - R60 Attic | Fiberglass blown in Cellulose blown in Fiberglass batts |
| 4 | R13 - R21 Walls R25 - R30 Floors and Ceiling R38 - R60 Attic | Expanding foam Fiberglass blown in Cellulose blown in |
| 5 | R13 - R21 Walls R25 - R30 Floors and Ceiling R38 - R60 Attic | Expanding foam Foam board Cellulose blown in |
| 6 | R13 - R21 Walls R25 - R30 Floors and Ceiling R49 - R60 Attic | Expanding foam Foam board Cellulose blown in |
| 7 | R13 - R21 Walls R25 - R30 Floors and Ceiling R49 - R60 Attic | Expanding foam Foam board Cellulose blown in |
Keep in mind that it is possible to layer insulation to get the best results. For example, if you already have batts, it’s possible to add blown-in insulation to them; you do not need to remove them to get better R-value.
Types of Insulation
There are several different types of insulation. Many of them can overlap, meaning that they can each be used in several areas, but some may be best for one area over another. They also have varying R-values, costs, and difficulties in installation.
| Type | Pros | Cons |
|---|---|---|
Radiant barrier ($0.10-$0.30/sq.ft.)
| Can help keep heat in the room you want it Inexpensive Easy to install | Used primarily in attics either below decking or on attic floor |
Fiberglass batts ($0.40-$1/sq.ft.)
| Inexpensive Can be used in walls or ceilings No known health effects | Compresses over time Cannot be easily used around pipes and obstacles Best installed in new construction or open walls |
Rockwool ($0.60-$1/sq.ft.)
| Good rigid insulator that doesn’t compress over time Fairly inexpensive | Difficult to find Best done in new construction or open walls Cannot be used everywhere |
Denim ($0.60-$1.20/sq.ft.)
| Eco-friendly Inexpensive Can be used in walls or ceilings No known health effects | Compresses over time Cannot be easily used around pipes and obstacles Best installed in new construction or open walls |
Cellulose ($1.20-$2/sq.ft.)
| Doesn’t compress over time Can be blown into walls or ceilings Can be blown into existing walls Can be blown in around pipes or obstacles | Loses R-value when wet May be more expensive than some others Minor respiratory irritation during installation |
Fiberglass blown-in ($1.20-$2/sq.ft.)
| Doesn’t compress over time Can be blown into walls or ceilings Can be blown in existing walls Can be blown around pipes or obstacles No known health effects | Not as effective as other materials |
($1.50-$2.00/sq.ft.)
| Fills cavities effectively Doesn’t compress or lose R-value over time Can be used inside walls or ceilings | Expensive to install Difficult to install Best done in new construction or open walls Gives off high levels of VOCs |
Foam board ($10-$30/panel)
| Creates tight building envelope Can help manage moisture in the home Acts as a sound barrier | Only for use on exterior of home Goes beneath siding, and requires the existing siding be removed Expensive Gives off high levels of VOCs |
Labor
The installation process and what the labor looks for your insulation will differ based on two factors: if your walls are open, such as in new construction, and what type of insulation you are using.
In new construction, labor costs will be lower for the insulation installation, because the walls are fully accessible. The areas being insulated can be easily seen and visualized, and you have more choices for what insulation you’re using. If the walls are closed and the insulation is being added to an existing home, then your choices are more limited. Batts and foam cannot be used without fully opening and exposing the walls. If you chose not to open the walls, you are limited to a type of blown in insulation.
For most homeowners looking to add insulation to an existing home, labor will consist of the installer cutting strategically placed holes in your walls to admit the insulation. It will be pumped or blown into your walls using a machine, usually in several places around the room to ensure good coverage. After the installation is complete, the cut section of the wall will be replaced, taped, and spackled 2 over. If this area is visible, you will want to repaint the wall to help the patch blend in. Professionals typically charge by the hour to install insulation, with costs ranging from $40-$70 per hour. For a 10’x10’ room, you can expect this to take between 2-3 hours at the most, depending on how easy the spaces are to access. This makes the labor portion of the project cost roughly $100-$150 of the $650 total.
Enhancement and Improvement Costs
Weatherstripping
If you are adding insulation to make your home more energy efficient, you may also want to add weatherstripping. Weatherstripping goes around windows and doors and helps stop air gaps, which can lower efficiency. This project costs around $168.
Soundproofing
Insulation can help reduce noise in the room, but some rooms may need additional soundproofing with the addition of acoustic paneling for walls and ceilings. Soundproofing a room costs around $1,000-$2,500 on average.
Installing Double Pane Windows
Another option to consider is to install double pane windows. Double pane windows help insulate this area, which can help lower energy costs. The cost of replacement windows is around $650-$1,500.
Drywall
If you choose to use spray foam or batt insulation, you will need new drywall 3 at the end of the project to cover the new insulation. The cost to add drywall to a room is around $1,500-$2,000.
Additional Considerations and Costs
- Some types of insulation can be installed DIY. This is most often recommended for open spaces like attics, and not interior wall cavities, which require you to open the wall.
- If you are unsure of whether or not you need insulation, you can get an energy audit done first. Energy audits will determine your biggest energy wasting areas, and can help recommend a plan of action, including insulation. An energy audit costs around $150 on average.
- Some energy efficient home improvements are eligible for rebates and tax credits. While the federal tax credit has expired, many states have their own incentive program for homeowners. Contact your local state government to find out if you are eligible for this savings.
- Be mindful of the fact that some contractors may provide estimates in inches only. This is because many insulations can be fluffed to appear fuller than they are. If this is the case, you are not getting the full R-value of that insulation. Make sure that they are insulating to the fullest extent to get your money’s worth.
- You can save some money by doing some prep work yourself, such as making sure the room is accessible for the machine, locating areas to be opened, or opening the wall yourself.
FAQ
- How much does it cost to insulate and drywall a room?
To fully insulate and drywall a room, your costs would be around $2,500.
- How much does it cost to insulate a 1,600 sq.ft. house?
The average cost to insulate a home of this size would be around $2,560.
- How much does it cost to insulate a 2,500 square foot house?
The average cost to insulate a home of this size would be between $3,500 and $4,500.
- How much does it cost to insulate a 1,000 sq.ft. attic?
The average cost to insulate an attic is $1,700-$2,000.
- How do you insulate a room?
If the walls are installed, a hole is cut and some type of fiber insulation is blown into the cavities.
- How much does it cost to insulate a room?
The average cost to insulate a room is around $650.
- Is it OK to insulate interior walls?
Yes, in fact insulating your interior walls will make the rooms of your home much more comfortable and energy efficient.
- How can I insulate my walls for cheap?
The least expensive way is to cut a small hole in the wall and blow in insulation. Otherwise, the drywall would have to be removed to install batts or foam, then reinstalled, which would add to the costs.
Remodeling Terms Cheat Sheet
Definitions in laymen's terms, cost considerations, pictures and things you need to know.See full cheat sheet.
2 Spackled: A paste, composed of gypsum plaster, glue, and water, used to repair holes and cracks in plaster before painting or wallpapering
3 Drywall: Type of plasterboard, commonly used to build walls and ceilings, composed of gypsum that is layered between sheets of heavy paper
How much does it cost to insulate a single room in my city?
Cost to insulate a single room varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.
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