Posted on 30th September 2021

The Role of Home Insulation in Energy Efficiency

Engineer installing insulation in an attic

By Evelyn Long, Editor-in-Chief of Renovated.


Without proper insulation, air can escape through your home’s windows and doors. This can waste large amounts of energy, which is why adding insulation is an important step in improving a home’s energy efficiency.


How Does Insulation Work?

Insulation works to slow down conductive heat flow. Conduction is the way heat moves through materials. It also reduces radiant heat gain. Radiant heat travels in a straight path and heats anything that absorbs its energy. Insulation prevents heat from escaping in the winter and then blocks it from entering in the summer.

To determine the effectiveness of an insulating material, it is given an R-value. This measures its resistance to conductive heat flow. The higher the value, the greater the efficiency.


The Major Types of Insulation

Insulation materials come in a variety of options. Here are some of the most common types.


1. Fiberglass

This is one of the most common types of insulation. Homeowners can buy it in batts placed between framing materials, such as studs or joints. Also, the thicker the batt, the higher the R-value. The material is non-combustible, creating less of a fire hazard.


2.  Mineral Wool

Mineral wool also comes in batts. The material can withstand higher temperatures and block out sound. It’s also moisture-resistant. Another benefit of mineral wool is the ability to hold its shape, making installation easier.


3.  Cellulose Loose-Fill

This type of material is made from recycled paper that is fire-resistant. Its installation process usually doesn’t require tearing into walls. Instead, the homeowner adds the insulation through a motorized blower.


4. Rigid Foam

These pink or blue foam boards can be seen in many homes. Homeowners commonly use them for insulating cement block walls in their basement. It’s also a denser material. This means homeowners don’t need to apply a thick layer to achieve a high R-value.


How Insulation Can Make Your Home More Efficient

Adding insulation prevents air from leaking through window or door openings. This can help to reduce the amount of energy wasted. Also, it prevents the heating system from overworking in the summer to keep the space warm. This can help the appliance consume less energy.

Insulation can also improve the efficiency of existing HVAC systems. This is because it prevents outdoor air from clogging the filters with dust. Clogged filters can cause the appliance to use more energy to function properly. Due to all this added efficiency, insulation can lower utility bills — homeowners can save up to 15% on heating and cooling costs.

Adding insulation can even provide more comfort. Insulation can help evenly heat a home, reducing high humidity and drafts. It can also improve air quality by limiting the amount of dust entering the property.

Another benefit is the insulation material is usually sound-absorbent, meaning homeowners can eliminate or reduce outside noises.


Best Places to Add Insulation

1. Garage Door

Openings in a garage door can cause air to escape. Replacing an older door with an energy-efficient model can reduce energy loss by up to 71%. Also, many garages share walls with other living spaces, so any heat moving through the door can impact the adjacent rooms.

This is why insulation is essential.

When deciding on a type of insulation, consider the R-value and custom design options. For flat garage doors, consider using foam board or reflective insulation.


2.   Attic

Attics are other areas that can waste energy. This is especially true for infrequently used or unfinished spaces. If not well maintained, the walls can form cracks, allowing air to escape. For attics, loose-fill or batt insulation is best. However, loose-fill is usually more cost-effective and provides better coverage.

Before starting, seal air leaks and make any needed roof repairs. You will want to insulate the knee walls, which are vertical barriers with attic space above.


3. Exterior Walls

If they’re not properly insulated, outdoor heat can enter the house through its walls. Also, indoor air can easily leave through small openings.

Are your walls already closed? Consider using blow-in insulation. This type of installation won’t disrupt other areas of the home, which can make the process a little easier on household members. However, if you’re remodeling, spray foam is the better choice.


4. Basement

A basement is often colder since it’s the lowest point of the house. Adding insulation will keep the space nice and toasty in the winter.

Consider using spray foam insulation between the studs if you’re framing the basement to turn it into a finished living space. It also provides extra stability and a great vapor barrier.


The Importance of Home Insulation

Adding insulation to a home can regulate its temperature and help improve its overall efficiency. It can also save homeowners money, so consider installing insulation today.