Wall Insulation

Wall Insulation

Whether your walls are drafty, your rooms are uneven in temperature, or you just want a quieter, healthier, more energy-efficient home, Evergreen is here to help.

If you’ve got rooms that are always colder – or hotter – than the rest of the house, chances are your walls are under-insulated. It’s a common issue we see in many older Maine homes and a primary cause of discomfort for homeowners who have switched to heat pumps for heating and cooling.

From historic capes to coastal farmhouses, Evergreen provides wall insulation services in PortlandRockland and the surrounding Southern and Coastal Maine areas, helping you improve comfort and energy efficiency – without compromising your home’s character or structure.

  • Eligible for up to $8,000 in Efficiency Maine rebates
  • Over 4,500 Maine homes improved since 2006
  • BPI-certified experts using building science-backed solutions
Beautiful white house in Maine
Evergreen team member taking equipment and blown insulation hose out of truck at job site

How We Insulate Existing Walls – Carefully and Effectively

We know that preserving your home’s character is important. Many of our customers live in historic Maine homes with original plaster, woodwork, or shingle siding that they want to protect.

Wall insulation can make a big impact on your comfort and energy efficiency—but it’s also one of the more complex upgrades we do. Think of it like minor surgery for your home’s envelope. It requires the right tools, techniques, and safety protocols, including lead-safe work practices.

That’s exactly why you want a team that knows how to do this work carefully, respectfully, and completely—without cutting corners.

What’s the Best Type of Attic Insulation?

We offer a range of attic insulation materials to match your home’s needs, but in most Maine homes, we recommend:

Step 1: Precision Drilling

We make small, precise 2.5-3” access holes—either inside (often behind baseboards or in closets) or on the exterior (behind siding or shingles). These openings are just large enough to install insulation but small enough to repair neatly.

Step 2: Dense-Pack Cellulose Installation

Before we install insulation, we seal leaks with spray foam to prevent air infiltration. This critical step protects against drafts that can weaken your insulation’s effectiveness and ensures your insulation performs as designed.

Step 3: Careful Restoration

Once the insulation is installed, we patch and restore each access point, including replacing siding on exterior walls. For both exterior and interior jobs, we leave the areas caulked, primed, and paint-ready. Meanwhile, your home will be more comfortable and energy-efficient!

Wall insulation is well worth doing for comfort and efficiency and to maximize the impact of heat pumps. However much of the cost comes from restoring finished surfaces, which makes this project best coupled with other renovations if possible.

Some Victorian-era Maine homes have balloon framing, which can allow us to insulate some or all of your walls from the attic much more easily. Every home is different, and we’ll help you understand your options during your free consult.

Insulation blower hose going out a window down to an insulation truck

The Benefits of Blown-In Wall Insulation

  • More consistent comfort from room to room (especially in homes that have switched to heat pumps)
  • Warmer in winter, cooler in summer
  • Quieter rooms and reduced outside noise
  • Fewer indoor drafts and temperature swings
  • Lower heating and cooling bills
Evergreen Home Performance Team Installing Attic Insulation

Affordable Home Upgrades with Efficiency Maine Insulation Rebates

Insulating your walls is a smart investment—and it’s made easier by Efficiency Maine rebates and other incentives. When you upgrade your home’s exterior wall insulation, you can qualify for:

  • Up to $8,000 in Efficiency Maine rebates
  • Loan payments as low as $50/month through Efficiency Maine & NEIF financing

Why Choose Evergreen Home Performance?

  • More than 4,500 Maine homes improved since 2006
  • Experts in historic and hard-to-insulate homes
  • BPI-certified professionals using the latest building science
  • 15,000+ home energy audits completed
  • More Mainers received Efficiency Maine insulation rebates with us than any other company in 2024
Evergreen Team Photo
Evergreen team smiling at each other

Book a Free Consult Today to Get Started

Whether your walls are drafty, your rooms are uneven in temperature, or you just want a quieter, healthier, more energy-efficient home, Evergreen is here to help.

We start every project with a free consult, and then move to a professional home energy audit to pinpoint exactly where your home is losing energy—and how to fix it.

It’s time you made your home more comfortable and energy-efficient. Call 207-594-2244 or contact us online to book your free consult and start your journey.

Feel whole-home comfort with the right wall insulation—we’ll guide you every step of the way.

BOOK YOUR FREE CONSULT TODAY

Evergreen has a professional and reliable team of people who do excellent work. If you want the best of the best in the area, select Evergreen to accomplish your insulation needs.

Mary E.

St. George

Evergreen did a fantastic job insulating our 1930's home. The onsite team was professional, clean, and really just a joy to interact with throughout the process. A blower test at the end showed a significant decrease in air leakage. I highly recommend Evergreen.

Kristen H.

South Portland

I cant say enough about this company and the benefits that it created for our family. They are very professional and have effectively re-insulated our home. The heating bill proves the point.

Bob O.

Springvale

Working with Evergreen was a dream! Professional, knowledgeable, and super clean work. Communication was fast and service impeccable. The bedroom floors in our 1960's split ranch will be warm with the new insulation between them and the garage. Bring on the snow! (not really, but sort of)

Jess Dee Proctor

We had Evergreen energy do blow-in cellulose. I was very happy with the result. They tested with blower-door before and after. House is now MUCH warmer. Also, in the time since when I've had to open walls for various access, I've been impressed with how they got the insulation packed in everywhere. I'd use them again.

Noah

Peaks Island

Evergreen did a fantastic job replacing 28 windows in our house. They were friendly, courteous, and very detail oriented. Brian did a great job planning, estimating and executing the project. Our energy use has dropped significantly since the work was done.

Alex B.

Kittery

"Working with Evergreen from start to finish was a great experience." See what our customers have to say about their experience with Evergreen Home Performance. 

Jeff L.

Our house still the most efficient home we’ve ever lived in. And we have you folks to thank for that! A special howdy to Brian Robinson please!

Bruce O’Donal and Eva Butler

Evergreen completed the work at my home thoroughly and professionally. An inspector from Efficiency Maine came to inspect afterwards and described it as "state of the art" and "outstanding". The crew was very pleasant and considerate during the project. Their cleanup each day was perfect. Communications with the office were easy and reliable. I am very satisfied.

Catherine H.

South Portland

This team of individuals was professional at all times. They set up barriers that kept the dust at a minimum. They conducted an air flow audit and cut the draft circulation from the outside in half by sealing cracks. They hauled out the old insulation and replaced it with blown in insulation with an R - 60 Value. They also did the rebate paperwork so that I could get my $1500.00 rebate from the state of Maine. I highly recommend Evergreen Home Performance!

Daniel B.

Rockland

A thorough inspection of our (older) house and its energy needs. Competent and personable work crew.

Jacob Watson

Evergreen removed and replaced the insulation in my attic. They did a great job!, Crew was excellent, and the whole thing went smoothly, and the attic was NOT easy to get into or work in, so kudos to some hard work done well!

Joel A.

Portland

Very easy process, start to finish.  Friendly, professional, and really know their stuff.  They made some improvements to our condo and we were very happy with how it played out.  Would definitely recommend them.

Clayton Eames

Really great experience from start to finish with Evergreen. They helped us prioritize what needed to be completed first, and has made a significant difference in our hearing costs already. Plus they were really friendly and considerate to work with!

Amy W.

Kennebunk

I am very pleased with my experience with Evergreen Home Performance. I met several times with Richard Burbank and he was very detailed in his explanations to all of my questions. He provided me with several options for improving the insulation to our home. The team of installers were very professional and respectful of our home. They did a great job of cleaning up every day after the days work and they were also very responsive to all my questions as well as we collaborated to get our home better insulated. It was a pleasure to work with Richard and…

Brian C.

Falmouth

Portland Buy Local
Efficiency Maine
EPA Lead-Safe Certified
Building Performance Association
BPI Certified