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
  • An additional 30% federal tax credit (up to $1,200 for insulation and air sealing)

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

We couldn't be more pleased with the easy, professional, high-value service from Evergreen. Having purchased an older home that had been in our family for generations, we needed multiple upgrades, including insulation throughout. Evergreen insulated our attic with blown-in cellulose, built a new, super-insulated attic hatch, sealed off the old one (which was just a piece of plywood in a closet ceiling), and also talked us through our best options to upgrade our heating system given the plans we have to add onto the house.

Tom G.

South Thomaston

We initially contacted Evergreen through Efficiency Maine for an energy audit, which was conducted promptly and professionally by Justin McEdward, one of their Energy Advisors who is BPI-certified. After a thorough inspection of our newly purchased home, Justin explained in great detail what we needed and did not need. It was agreed that Evergreen would remove all of the existing attic insulation, which was not adequate, and replace it with blown in cellulose, to a rating of R-60.

Thomas W.

Scarborough

Evergreen listened and produced a thoughtful evaluation, proposal and comprehensive plan for our attic and basement. They exhibited excellent workmanship, teamwork, and came back as planned after the completion of the job to test the outcomes. Their overall performance as insulation and home improvement contractors is truly outstanding and we highly recommend them.

Susan S.

Saco

In the final stages of selling our home, and with a closing date set, an inspection came across an unanticipated issue in our attic. We quickly called in contractors, but nobody was able to identify the source of the problem. Then we thought of Evergreen. Brian Robinson was on site the next morning and immediately identified the source (a faulty roofing job completed three years earlier which had effectively sealed up portions of the ridge vent and restricted air flow - not easily visible with a quick inspection).

Robin McIntosh

Camden

We just finished a large project air sealing and reinsulating our 1890s basement and attic. It had been completely renovated 8 years ago, but still felt cold, and lacked proper energy assessment and corrections. We met with Justin in December and were very impressed with his knowledge, professionalism and communication skills and knew Evergreen was who we wanted to work with. Dave was our on hands project manager and was excellent. The office staff has been quick to respond and helpful as well when needed.

E Gallant

Kennebunk

"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.

Update 12/2018: Evergreen has completed Phase II of my house (insulating and installing air/moisture barrier on exterior walls, replacing old windows) and now that heating season is upon us, the difference is astonishing. The house is tight as a drum and so easy to keep warm. Worth every penny. Thank you all! Working with Evergreen was a positive experience from start (no charge energy audit) to finish (a MUCH more comfortable home). Brian Robinson spent a lot of time with me on the audit, explaining clearly what he was finding in my ca.

Rebekah W.

Rockport

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

I have always been impressed by the high level of service, quality of work, and excellent follow-through provided by Evergreen Home Performance in the three projects that they completed at the Wells Reserve at Laudholm over the past several years.

Paul D.

Wells

I never leave reviews, but had a great experience with Evergreen and wanted to spread the word! In short, we worked with them to insulate our roof this winter and have noticed surprising immediate results. The constant ice dams I have wrestled with are completely gone, and the home is noticeably more comfortable. It's a little too early to tell if our oil bill is going to reduce, but I imagine we will see an impact there as well.

Joel W.

Portland

Thorough, smart, informative, integrated, and communicative -- that's how my experience was with Evergreen even with the covid interruption midstream. The team picked up where they left off, insulated basement and air sealed attic and knee wall in 100' temps under the eaves! This business group was a pleasure to work with.

Karen W.

Gray

Evergreen did an amazing job insulating our historic home. Their professional staff worked hard to ensure the tough areas in the attic were covered, and clearly communicated their progress. We are seeing the results with our discounted heating bills. Thank you, Evergreen!

Melissa Knoll

Portland

From start to finish, our experience was incredible. Justin was extremely helpful. The crew was fast, friendly, and efficient. And most importantly, our home is WAY warmer and our heating is less costly. I'd highly recommend evergreen to anyone looking to upgrade their home!

John S.

South Portland

I highly recommend Evergreen! 1st, I had a home efficiency inspection (that was free) & Bryan P. was great! He took the time needed, asked & listened to what I thought were priorities, explained clearly what he thought were priorities & why, then gave me numerous options. No pressure whatsoever. Then I had my attic sealed & insulated as the 1st step & Bryan came along on day 1 to introduce everyone & make sure we were all on the same page. Bruce's team (inc. Kelsey & Roland) did the work - they were exceptional!!

Melissa M.

Kennebunk

The Evergreen Team did a fabulous job, well exceeding our expectations, In just over a week they transformed our very drafty, noisy 213 year old house into a snug, draft-free, quiet haven with warm floors! The team was prompt, did everything they said they'd do and more. We are thrilled!

Trudy M.

Bridgton

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