What to Know About Insulation When Buying a House
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What to Know About Insulation When Buying a House

Real Estate | existing home insulation

What to Know About Insulation When Buying a House Blog Feature
Amanda Emery

By: Amanda Emery on December 17th, 2025

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Pressure mounts when you’re in the home-buying process.

There’s the stress of submitting your bid, researching the neighborhood, consuming as much knowledge as possible about a home’s intricacies, and a lot more.

One detail you won’t want to overlook when perusing a house you hope to transform into your dream home is its insulation.

One of the first things you should do when buying a home is ask the agent what type of insulation is in the home. Furthermore, ask for the home's gas and electric bill history. This will give you a good idea of how well the home’s insulation is functioning.

Anyone serious about selling their home should have this information readily available. If the current homeowner doesn’t have the information, a home inspector can provide it.

Let’s examine some of the other things you need to know about the insulation in your dream home.

Key Points:

• Always ask about insulation upfront. Find out what type of insulation the home has and request past gas and electric bills to gauge energy efficiency.
• Fiberglass insulation is outdated. It settles over time, can lose up to 40 to 50 percent of its effectiveness in cold temperatures, and must be installed perfectly to perform well.
• Cellulose requires maintenance. While acceptable in attics, it needs sufficient depth, settles over time, and can create messes throughout the home.
• More insulation isn't always better. Excess insulation can lead to moisture issues, added weight, and potential structural problems if not installed correctly.
• Your roof tells a story. Curling shingles, excessive wear, or ice dams can signal insulation or ventilation problems inside the home.
• Energy audits are invaluable. A home inspector who offers a home energy audit can pinpoint where energy is being lost and whether insulation upgrades are needed.
• Understanding insulation protects your budget. Knowing the home's insulation condition helps you avoid surprise costs and improves long-term comfort and efficiency.

Does the Home Have Fiberglass Insulation?

Fiberglass insulation is an old technology that is less effective than other options.

There are a few signs that indicate insulation needs to be replaced or improved. Here's what you should look for.

Fiberglass in the Walls or Attic

Fiberglass in the walls or attic definitely needs to be updated, as it has been shown to break down and settle over time.

Because of this, its ability to insulate the home diminishes as its R-Value decreases by 40 percent – potentially costing you money that you could have otherwise saved.

Cold Temperature Reaction

When the temperature outside is below 20 degrees, fiberglass loses up to 40 percent of its effectiveness.

That percentage increases to 50 percent when the temperature drops below zero.

Install Must Be Perfect

Finally, with its lower R-Values, fiberglass must be installed perfectly to be effective at normal temperatures.

The material also allows for some airflow even when installed correctly.

Does the Home Have Cellulose Insulation?

Cellulose insulation is not the best choice for an attic. It’s acceptable, but you will have to maintain it.

Maintaining Cellulose

Cellulose insulation is only effective in an attic when at least 12 inches have been installed.

The material’s R-Value is generally around 3.7 per inch. However, it loses effectiveness over time due to settling and shifting.

Cellulose Can Leave a Mess

Additionally, as loose-fill insulation, cellulose tends to find itself throughout a home’s ductwork, walls, and fixtures.

More Isn’t Necessarily Better

A lot of folks think that when it comes to insulation, more is always better. But that’s not quite the case!

Just because you take a peek in the attic and see a ton of insulation doesn’t mean you’re all set and good to go.

Overdoing it can lead to headaches, such as moisture problems, added weight, and even structural damage from the material shifting.

So, while more isn’t always better, properly installed insulation definitely is.

The Roof Can Signal Insulation Problems

The roof can be a telltale sign of insulation issues. If you notice that your roof looks a little worse for wear—like it's dried out, curling, or even scorched from the sun—that’s a big red flag.

These signs often mean your home might not have enough insulation or proper ventilation. Without adequate insulation, heat can sneak in during the summer, making your roof work overtime. In the winter, the heat escaping from your home can cause ice dams, leading to all sorts of damage.

So, if your roof's looking a bit rough around the edges, it’s worth taking a closer look at your insulation and ventilation situation. It might just be time for an upgrade.

Find a Home Inspector Who Offers a Home Energy Audit

When it’s time for a home inspection, it helps to find an inspector who does a home energy audit.

A home energy audit provides insight into where and how a home loses energy through diagnostic testing, according to the U.S. Department of Energy. This will display the current insulation's effectiveness and whether it needs upgrading or additional insulation in some spaces.

Buying Your Dream Home

Buying a home is about knowing what you’re getting into.

You most likely have a budget and need to consider all potential future costs, not just the price of the home.

Knowing the insulation situation saves you money upfront and in the long term, as you avoid future problems.

If the insulation in your new home needs an upgrade, call us at 866-900-3626 to request an estimate or fill out the form on our website.

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Should I Replace Old Insulation in My Existing Home?

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About Amanda Emery

Amanda previously has worked as a breaking news and crime reporter, TV news producer, and editor in Flint and Detroit. Throughout her career as a journalist, she has won several awards from The Society of Professional Journalists - Detroit Chapter and the Michigan Press Association. As part of the RetroFoam of Michigan family, Amanda uses her experience as a journalist to write content that will help educate homeowners on the benefits of foam insulation. When Amanda isn’t writing, she’s spending time with her husband and rescued huskies. She also loves knitting, making art, cooking, and hosting dinner and a movie night for friends and family.