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 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

We had Evergreen come out to our tiny old (100+ year old) house to see what they would recommend for decreasing our carbon footprint, saving money, and increasing our comfort in the cold season. Richard and Bryan were great to work with, patiently answering our many questions and walking us through multiple options. We could only afford to tackle a few areas this year; we ended up replacing some windows and having them weatherize the entire house.

Alan M.

Falmouth

Evergreen was so helpful in securing us Efficiency Maine funding for a big attic insulation project early this winter. They did all of the paperwork, and totally guided us through a vermiculite removal process that included a payment from a trust for the procedure. I could instantly feel the second floor being so much warmer than before. The boiler does not kick on nearly as frequently since they completed the job. It was worth every penny! Brian Robinson was so thorough throughout the whole process including a full walk through after the job had been completed.

Todd W.

Camden

We needed basement encapsulation to stop moisture coming up into the house from our regularly flooding basement. We had mold growing on windowsills and furniture. All the staff were friendly, respectful of our home, and easy to work with. Humidity has gone from 70% down to 40% and mold has not grown back after two months. Very grateful.

Sarah C.

Belfast

The Evergreen team was amazing from initial assessment and planning to the crew that came to complete the work. Our basement encapsulation is the best money we've spent on our house by far. The work was thorough and high quality. And what a wonderful group of people to work with. I highly recommend Evergreen!

Martha Bracy

Evergreen Home Performance shows its expertise from start to finish. Evergreen did three house projects in winter/spring/summer 2020 for me, attic insulation, crawl space under a porch insulation, and basement foam/vapor barrier. From my initial discussion with Bryan, I understood the reasons for choosing different types of insulation, the associated costs, and time estimates. Evergreen scheduled in advance, came when they said they would, and the crews were highly professional in their work and demeanor.

Iris S.

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

My experience with Evergreen was excellent. From their thorough and thoughtful initial consultation to their detailed post-work visit, the team was professional, knowledgeable, and responsive. Their workmanship was top notch. Our home is now much warmer and more efficient. I highly recommend their services!

Douglas R.

Edgecomb

Last week, my oil company asked if we were using some other kind of fuel because our usage was so much less than they had expected We are very happy with the results; the house is much more comfortable

Steve T.

St. George

From beginning to end – that is from the moment Justin McEdward stepped into our home to assess our energy conservation needs until the crew left – the Evergreen Home Performance process went absolutely smoothly. Justin made a thorough inspection and took pictures with an infrared camera. His proposal described the scope of work in detail, and he explained what we could expect the proposed work to accomplish. Our proposal was forthcoming within a couple of days, and Justin was available to discuss it and answer questions.

Adrienne Harkavy

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

Jacob Watson

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

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

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

Evergreen came out 2 years ago to do an assessment and insulate our roof. This year we had them come back and do the basement as well. They are hands-down the best crew we've ever hired to work on our house. They are experts at what they do, and super meticulous in their work. After working in our house for a week with blown insulation, there was no trace they were ever here. We've seen a huge decrease in our energy bills while at the same time the house has become way more comfortable. Can't recommend them enough.

RC Lations II

Portland

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