Spray foam insulation costs in New Hampshire vary based on the size of the project, type of foam, application thickness, accessibility, existing insulation, and preparation required. Open-cell foam generally costs less than closed-cell foam, while crawl spaces, attics, walls, and new construction can have very different installation requirements. A property assessment is the best way to determine your actual project cost.

What Determines the Cost of Spray Foam Insulation in New Hampshire?

There isn't one standard price for spray foam insulation because every building is different.

A contractor needs to consider the area being insulated, the type and thickness of foam required, how accessible the space is, and whether preparation or removal work is necessary.

The biggest factors include:

• Square footage: Larger projects generally require more material and labor.
• Type of foam: Open-cell and closed-cell foam have different material requirements and performance characteristics.
• Thickness: Applying more foam increases material requirements.
• Location: An open attic may be easier to access than a tight crawl space or existing wall cavity.
• Existing insulation: Old or damaged insulation may need to be addressed before new insulation is installed.
• Preparation: Moving items, protecting surfaces, or addressing building issues can affect project requirements.
• Building construction: Older homes, additions, renovations, and unusual framing can require different approaches.
• Project type: Residential, commercial, and new-construction projects each have different considerations.

For these reasons, a professional assessment is more useful than relying on a generic online price calculator.

Open-Cell vs. Closed-Cell Spray Foam Cost

One of the first decisions affecting a spray foam project is the type of foam being used.

Open-Cell Spray Foam

Open-cell foam is lighter and expands significantly after application. Weathertight Spray Foam describes it as an economical option for filling larger spaces and lists an R-value of approximately 3.9–4.2 per inch.

Open-cell foam may be appropriate for applications such as certain:

• Attics
• Walls
• Ceilings
• Sound-control applications

Because it uses less material to fill a given volume, open-cell foam can be a cost-effective choice when the application is appropriate.

Closed-Cell Spray Foam

Closed-cell foam is denser and provides a higher R-value per inch than open-cell foam. It also offers greater resistance to moisture and water vapor.

The U.S. Department of Energy's Building America guidance identifies closed-cell spray foam as having substantially higher R-value per inch than open-cell foam, although actual performance varies by product.

Closed-cell foam is commonly considered for applications such as:

• Crawl spaces
• Rim joists
• Foundations
• Under-slab insulation
• Areas where moisture resistance is important
• Spaces where higher R-value per inch is beneficial

Because closed-cell foam is denser and requires more material, it generally costs more than open-cell foam.

How Much Does Attic Spray Foam Cost?

Attic projects can vary significantly depending on whether foam is installed along the attic floor or roofline, the size of the attic, existing insulation, accessibility, and the amount of preparation required.

Attics are also one of the areas ENERGY STAR identifies as having significant opportunities for energy savings and comfort improvements. The agency recommends addressing attic air leaks before adding insulation.

For a New Hampshire homeowner, an attic assessment can help determine whether spray foam is appropriate and where it should be installed.

If you're considering this type of project, see our [Attic Spray Foam Insulation] service page for more information.

How Much Does Crawl Space Spray Foam Cost?

Crawl space projects can also vary considerably in price.

A crawl space may be difficult to access, have existing insulation that needs attention, or have moisture-related issues that should be addressed before insulation is installed.

Closed-cell spray foam is often considered for crawl spaces because of its density and moisture resistance. However, the appropriate solution depends on the specific conditions of the crawl space.

ENERGY STAR identifies basement and crawl-space air sealing and insulation as important areas to consider after addressing the attic.

Weathertight Spray Foam also provides [Crawl Space Spray Foam Insulation] for homes throughout New Hampshire and the Seacoast.

Does Spray Foam Cost More Than Fiberglass?

Spray foam typically has a higher upfront installation cost than traditional fiberglass insulation.

However, price isn't the only factor to consider.

Spray foam can combine insulation with air sealing in the areas where it is applied. ENERGY STAR explains that air sealing and insulation work together to improve comfort and energy efficiency.

The right comparison should therefore consider:

• Insulation performance
• Air sealing
• Moisture considerations
• Installation requirements
• Long-term durability
• Existing building conditions
• Overall project goals

The least expensive insulation material isn't necessarily the right solution for every part of a home.

Can Spray Foam Help Lower Energy Bills?

Improving insulation and air sealing can reduce unwanted heat transfer and air leakage.

ENERGY STAR estimates that homeowners can save an average of 15% on heating and cooling costs, or about 11% on total energy costs, through cost-effective air sealing and insulation improvements in typical existing homes. Actual savings vary based on climate, home construction, existing insulation, and other factors.

That doesn't mean spray foam will automatically reduce a particular home's energy bills by a specific percentage.

Instead, the potential benefit depends on what problems currently exist in the building envelope.

A home with significant air leakage and inadequate insulation may have more opportunity for improvement than a newer, well-insulated home.

Why New Hampshire Homes May Benefit From Air Sealing

New Hampshire homes experience significant seasonal temperature changes, including cold winters and warm, humid summers.

Air leaks can make a home feel drafty and allow conditioned air to escape.

According to ENERGY STAR, many of the most significant air leaks in homes are found in less obvious locations, including attics, basements, and rim joists.

Common symptoms include:

• Drafty rooms
• Cold floors
• Uneven temperatures
• High heating or cooling bills
• Cold areas near exterior walls
• Ice-dam concerns
• Difficult-to-heat rooms

Spray foam may be part of the solution when air leakage and inadequate insulation are contributing to these problems.

Does the Location of Your New Hampshire Home Matter?

The type of property and its location can influence the insulation strategy.

New Hampshire Seacoast

Homes in Portsmouth, Hampton, Rye, Exeter, Dover, and surrounding Seacoast communities may have additional moisture and coastal-weather considerations.

Closed-cell spray foam may be appropriate for certain applications where moisture resistance is important.

See our location pages for:

• Portsmouth, NH
• Hampton, NH
• Rye, NH
• Exeter, NH
• Dover, NH

New Hampshire Lakes Region

Homes around Lake Winnipesaukee and the Lakes Region include year-round residences, vacation homes, older properties, and new construction.

The appropriate insulation strategy depends on the building's construction and how it is used.

Southern New Hampshire

Homes around Manchester, Concord, and surrounding communities can have very different insulation needs depending on their age and construction.

Older homes may have areas that were never properly air sealed, while new construction can provide an opportunity to design the building envelope from the beginning.

Is Spray Foam Worth the Higher Upfront Cost?

That depends on the property and the goals of the project.

Spray foam may make sense when you're trying to address several issues at once, such as:

• Air leakage
• Inadequate insulation
• Drafts
• Cold floors
• Difficult-to-insulate areas
• Certain moisture-control requirements
• Comfort problems

ENERGY STAR notes that properly sealing and insulating a home can improve comfort and energy efficiency, with potential savings varying significantly from one property to another.

The best way to determine whether spray foam makes financial sense is to compare the recommended work with your property's current condition and your long-term goals.

What Should Be Included in a Spray Foam Estimate?

Before choosing a contractor, make sure you understand what the estimate covers.

A quality estimate should clearly identify:

• Areas being insulated
• Type of spray foam
• Proposed thickness
• Approximate square footage
• Preparation requirements
• Removal of existing insulation, if applicable
• Any additional work required
• Total project cost
• Expected installation schedule

Don't compare estimates based solely on the final dollar amount.

Two contractors may recommend different products, thicknesses, or scopes of work, making the estimates difficult to compare without understanding what is included.

Why Choose Weathertight Spray Foam?

Weathertight Spray Foam is a locally owned and operated spray foam insulation company serving homeowners and businesses throughout New Hampshire, Southern Maine, and Northern Massachusetts.

The company has 15+ years of industry experience and provides open-cell, closed-cell, and hybrid spray foam solutions for residential, commercial, renovation, and new-construction projects.

Our process includes:

1. Consultation
2. Property assessment
3. Recommendation
4. Estimate
5. Preparation
6. Installation
7. Final walkthrough

This approach allows the insulation recommendation to be based on the property rather than simply applying the same solution to every project.

Frequently Asked Questions

What is the average cost of spray foam insulation in New Hampshire?

There is no single average price that accurately represents every New Hampshire project. Cost depends on foam type, thickness, square footage, accessibility, existing insulation, preparation, and the specific application.

Is open-cell spray foam cheaper than closed-cell?

Generally, yes. Open-cell foam uses less material to fill a given volume and typically has a lower material cost. Closed-cell foam provides higher R-value per inch and greater moisture resistance, which can make it appropriate for different applications.

Does spray foam increase home value?

Insulation and air sealing can improve comfort and energy efficiency, but the effect on a home's resale value varies. Spray foam should primarily be evaluated based on the building-performance improvements it provides.

Can spray foam be installed in an existing home?

Yes. Spray foam can be installed in many existing homes, including attics, crawl spaces, walls, rim joists, basements, and other areas. The installation approach depends on the home's construction.

Does spray foam help with drafts?

Yes. One of spray foam's important functions is air sealing. When properly applied, it can help reduce unwanted air movement through gaps and cracks in the building envelope.

Does Weathertight Spray Foam offer free estimates?

Yes. Weathertight Spray Foam offers free consultations and estimates for qualifying projects.

Key Takeaways

• Spray foam insulation costs vary significantly from one New Hampshire property to another.
• Open-cell and closed-cell foam have different characteristics and applications.
• Closed-cell foam generally costs more but provides higher R-value per inch and greater moisture resistance.
• Attics, crawl spaces, walls, rim joists, and foundations can all have different installation requirements.
• Air sealing and insulation work together to improve comfort and energy efficiency.
• ENERGY STAR estimates that cost-effective air sealing and insulation can save an average of 15% on heating and cooling costs in typical existing homes, although individual results vary.
• The best way to determine your project's cost is with a professional property assessment and detailed estimate.
• Weathertight Spray Foam serves New Hampshire, Southern Maine, and Northern Massachusetts.

Get a Spray Foam Insulation Estimate

If you're considering spray foam insulation for your New Hampshire home or business, start with a property assessment.

Weathertight Spray Foam can evaluate the area, discuss your options, and provide an estimate based on the specific requirements of your project.

Call Weathertight Spray Foam today at 603-343-3266.

About the Author

Weathertight Spray Foam is a locally owned and operated spray foam insulation company with 15+ years of industry experience. The company specializes in residential and commercial spray foam insulation throughout New Hampshire, Southern Maine, and Northern Massachusetts.