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Is It Worth Insulating an Old House? Here’s How To Decide

Is It Worth Insulating an Old House? Here’s How To Decide

Whether you’re wondering if you should insulate the old house you’ve owned for years or thinking of buying a fixer-upper, you’ll come across insulation problems. Is it necessary to pay the upfront cost of insulation, even if it’s for an older or historic home?

It’s worth insulating an old house because it’ll help you save on electricity bills down the road. A home without insulation drains the heating and cooling elements of power, making them work overtime. By adding insulation, you’ll prevent your home from leaking air and energy.

This article will cover everything you need to know about the importance of insulating an old home, whether your home likely has insulation, and how to start the insulation process. 

Why Insulating an Old House Is Worth It

The main benefit of insulating a home is the financial advantage. While there’s an upfront cost to insulation, the overall cost of maintaining an uninsulated house can be up to 30% higher (source).

Paying for energy can be one of the most expensive bills for a household. Half of an average electric bill is money towards heating and air conditioning a residence. However, without insulation, those costs are even higher.

Warm or hot air is always drawn toward colder areas. For example, if you drive your car with the heat on but leave a window open in the winter, warm air will naturally migrate out of the window and toward the cold. In a home, it does the same thing. If there are cracks, leaks, or uninsulated areas, when your heater is working, the warm air escapes from the home and gets into the cool outside (source).

When you add insulation, there’s no way for the warm air to leave your home. The insulation prevents air from leaking out, giving it no place to go besides inside to heat your home.

Note: The one critical factor you should consider when determining whether or not to insulate an older home is how long you intend to live it in. If you anticipate staying in the home less than 5 years, the cost of insulating may not be recouped by the savings in energy costs. This will depend largely on the amount of current insulation already in place and the severity of energy leaks throughout the home’s thermal envelope.

Do You Need To Insulate an Older Home?

You need to insulate an older home if you want to lower your electricity bill for years to come. Insulation is essential to protect your wallet and your home’s functionality in the future.

When it comes to insulating an older home, there are some misconceptions about the need, cost, and how best to complete the process. Let’s take a look at the most critical factors in insulating an old home.

What Does Insulation Do?

Insulation keeps heat, material, sound, or electricity from dispersing or moving between areas. The word insulation also refers to the material used to keep things in place or to prevent movement.

In a home, insulation is mainly used to keep hot and cold air from entering or exiting. During the warmer months, insulation keeps cool air inside the home and warm air outside, while in the winter, it protects the hot air made by the furnace from exiting the house.

Are Older Homes Built With Some Insulation?

Older homes were built with some insulation. But old homes were constructed early enough that the residents just changed their clothing to match the weather rather than heating or cooling the house. Modern homes today are more energy-efficient than older homes. 

When older or historic homes were made, builders used different materials and methods. Rather than planning on electrical power, those homes may have been designed with wood frames, thick walls, and a stove that provided minimal heat (source).

Because of that, you might think that the cost of insulating your older home will be too high. But realistically, it’ll be way more expensive in the long run to continue to live in your home with no insulation. The only homes designed for comfort without insulation are energy-efficient buildings, which didn’t become popular until more recently (source).

You Must Perform an Insulation Check

Before insulating your old home, professionals advise that you determine how much insulation the building already has. The best way to do that is to complete an insulation check or home energy audit with a qualified home energy assessor. Additionally, they can also check that the sealing in your home is protective enough to prevent any leaks.

After checking that your home is appropriately sealed and determining the amount of insulation you need, you’ll decide on the areas of insulation. The essential insulating areas include attics, ceilings, walls, foundations, basements, crawl spaces, and garages (source).

Insulation Comes in Different Forms

The most common types of insulation used nowadays come in four forms. Loose-fill insulation contains small pieces of material that are blown or placed into the space. Cellulose and fiberglass are the most common forms of loose-fill insulation, offering an inexpensive option that the homeowner can sometimes add (source).

Rigid board insulation is usually made of foam, polyisocyanurate, or polystyrene. Those materials are relatively expensive and can also be set up by a non-professional. On the other hand, foamed-in-place materials are sprayed onto the surface, where they harden and are then trimmed. They can be more expensive but go in crevices and effectively stop humidity in addition to air.

Batts or blankets like fiberglass batts are also easy to install and inexpensive, but some people avoid them because the installation process is arduous. You might see other insulation materials like wool or plastics in the past, but they are uncommon today.

Get a Professional Contractor To Insulate Your Home 

The last important consideration is whether you want to go with self-installation or the help of a professional. In most cases, especially with a historic home, it’s a better idea to go with a professional contractor.

Insulation can be a challenging process that should be done correctly, and if you decide to do it yourself, you might miss areas or places. Certain insulation materials can even be dangerous to handle, so it’s better to work with a professional to make sure you do it effectively.


Insulation is important, even in older homes. Though the upfront cost isn’t cheap, it’s much more budget-friendly to have good quality insulation in the long term.

Most older homes are made without insulation, but that allows air to leak through and makes your electric appliances work harder. You’ll see increased bills from your:

  • Furnace
  • Heating element
  • Air conditioner

By adding proper insulation to your older home, you can save significant money on electricity bills in the future.

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