The cost to insulate a basement varies based on materials, size, and other factors, as well as how much of the work you wish to perform yourself.
Blown-In Insulation Cost in Washington, D.C. [2025 Data]
Normal Range: $1,205 - $2,563
Insulation service costs depend on your project and location. Check with a local pro for your specific job.
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Highlights
Blown-in installation in Washington, D.C. generally costs $1.40 to $3.50 per square foot
Larger insulation areas raise the total cost because crews need more material and time to complete the job.
Permit fees may come into play if insulation work connects to electrical or ventilation adjustments.
Insulation plays an important role in managing indoor comfort in Washington, D.C., especially with the area’s mix of cold winters and humid summers. Blown-in insulation typically averages around $1,861, but most projects range from $1,205 to $2,563. Your total cost will depend on factors such as the level of coverage your home requires and the materials you choose. This guide breaks down these and other cost factors, allowing you to plan ahead for this project.
Blown-In Insulation Cost Factors
The cost of blown-in insulation in Washington, D.C. varies quite a bit based on factors like how much coverage your home needs and the R-value you choose. Understanding each cost factor can help you create a realistic plan for this project.
Size of the Area
The biggest cost factor is the size of the area that requires insulation. A larger area requires more insulation and labor, increasing the overall price. This metric is calculated by multiplying your square footage by the cost per square foot of your chosen insulation materials, which are detailed below. However, a general range for blown-in insulation per square foot is $1.40 to $3.50 depending on the type.
| Area in Square Feet | Blown-in Insulation Cost Range |
|---|---|
| 500 | $700–$1,750 |
| 1,000 | $1,400–$3,500 |
| 1,500 | $2,100–$5,250 |
R-Value
When measuring the efficacy of any insulation material, it all boils down to the R-value. Generally speaking, higher is better, though there are two metrics to consider. There’s the overall R-value and the per-inch R-value. For example, if you want a total R-value of 30, you’ll need ten inches of insulation at an R-value of 3.0 per inch. Materials with higher R-values cost more, like sheep’s wool, but you don’t need as much material to complete the installation.
Below is a breakdown of R-values and the corresponding prices:
| R-Value | Number of Bags per 1,000 sq. ft. | Description | Price Range |
|---|---|---|---|
| R-13–R-21 | 7–10 | Only works for interior walls or low-priority spaces; it won’t control heat loss well enough for D.C.’s long heating season. | $250–$370 |
| R-30–R-49 | 15–20 | A reasonable level for improving older homes that leak heat in winter, but it may still fall short if you want strong year-round efficiency. | $540–$1,550 |
| R-38–R-49 | 20–26 | A good fit for most D.C. homes because it helps maintain steadier indoor temperatures as the weather flips between cold snaps and mild days. | $1,150–$1,650 |
| R-49–R-60 | 26–32 | This level gives you the most consistent comfort during D.C.’s long heating months. | $1,550–$2,050 |
Type of Insulation
The cost to install blown-in insulation depends on the type of insulation you choose for the project. Anticipate spending anywhere between $0.60 and $2.30 per square foot for materials, not including installation. Below is a breakdown of each blown-in material type and how much it costs.
| Type of Blown-In Insulation | R-Value per Inch | Average Cost per Square Foot |
|---|---|---|
| Fiberglass | 2.5 to 3.5 | $0.60–$1.15 |
| Wet-spray cellulose | 3.2 to 3.7 | $0.75–$1.85 |
| Dense-pack cellulose | 3.2 to 3.7 | $2–$2.30 |
| Rockwool | 3.0 to 3.7 | $1.50–$2.25 |
| Natural wool | 3.5 to 3.8 | $1.70–$2.30 |
Blown-In Insulation Pro Costs
The cost of hiring a pro to install blown-in insulation in Washington, D.C. often includes factors beyond the labor itself. For instance, in some cases, you may need to pay for permits, as well as taxes on the materials.
Labor
Most insulation crews in D.C. charge between $100 and $180 per hour, depending on the number of installers on the job and the complexity of the space. Rates tend to increase when the project involves factors such as access difficulties, older construction that requires extra care, or areas that necessitate slower, more detailed installation.
Permits
You likely won’t need a permit in Washington, D.C. for blown-in insulation alone, but you may need one if the work affects ventilation paths or involves any electrical adjustments inside walls or ceilings. When a permit is needed, fees generally fall between $90 and $250, but the final amount depends on which part of the home is being opened and whether an inspector needs to verify access to wiring or mechanical systems.
Insurance and Licensing
Insulation contractors in Washington, D.C. are required to carry liability insurance and workers’ compensation. They also need a Home Improvement Contractor License issued by the District. These protections cover you if the work causes damage or if someone is hurt on the job, but the cost of maintaining them is part of what shapes a contractor’s pricing.
Taxes
Washington, D.C. applies a sales tax of about 6% to insulation materials, but labor for residential insulation work is generally not taxed. It’s worth checking your estimate to ensure the tax is only applied to the materials, thereby avoiding unnecessary fees.
Does New Blown-In Insulation Increase Home Value?
Blown-in insulation usually doesn’t move a home’s resale value on its own, but buyers often notice upgrades that help manage energy use and create more consistent comfort. So installing it can still give your home a competitive edge in the market by reducing heat loss and helping indoor temperatures stay steadier during long heating months.
How Angi Gets Its Cost Data
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.
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