Feldco Fast

Quality Windows, Siding
& Doors Since 1976

R-Value: Learn Everything You Need to Know

Many homeowners believe that a window is just a window and a door is just a door. You can get anything as long as it looks pretty. But did you know that know the r-value of windows and doors could end up saving you money while effecting the temperature of your home?

You’re probably wondering, “What is r-value? I’ve never heard of it.” It’s an industry measurement that helps determine the energy efficiency of materials which can help save you money and prevent uncomfortable nights in your home.


In this article, we’ll go over what r-value is, how it’s measured and why it’s important for you to know. You’re about to change how you think about home improvement.

What Is R-Value?

You already know that the r-value of a window or door is the industry measurement that determines energy efficiency. However, there’s more to it than that.

It measures a material’s resistance to heat flow as well. That means you’ll know how easily heat will be able to pass through your windows and doors. If you’re looking to start a home improvement project, it’s important to keep r-value in mind.

How Is R-Value Measured?

Measuring r-value is a little bit complicated.  The “R” represents the thickness of a material or its resistance to heat. It’s determined by finding the change in temperature and multiplying it by the area and time. You take that number and divide it by heat lost. The formula looks something like this:

R = ▲T/Q or R = (▲Temp x Area x Time) / Heat Loss

The good thing is, you won’t have to measure a window or door’s r-value – it’s usually given to you by the home improvement company you’re purchasing it from. What you do need to know is the higher the r-value, the more energy efficient the material is.

losing heat through your windows

What Products Have an R-Value?

There are many different products that have an r-value. Anything from windows, siding, attic insulation, roofs, doors and even garage doors display the measurements. These are all extremely important because the make up the exterior of your home. You want your home to be well protected from outside temperatures and the elements so it’s important to pick materials with high r-values.

R-Value Vs U-Factor

There’s another important measurement that helps determine a material’s energy efficiency: u-factor. You’re probably wondering, “what’s the difference between r-value and u-factor?”

U-factor is the inverse of r-value, meaning that it’s the measurement of the heat loss experienced by a material. It’s measured on a scale of 0.25 to 1.25. The lower the number, the less heat the materials loses.

What’s Solar Heat Gain Coefficient?

Along with r-value, another important metric you should understand is the solar heat gain coefficient (SHGC). It measures how much heat you allow into your home. It also determines how long it takes for the air inside your home to be cooled or heated.

The SHGC  is shown as a number between 0 and 1. The lower the number, the less heat that’s transmitted. You can find the number displayed on the window when you’re looking for a replacement.

Why Is This Important Information for Homeowners?

That’s all well and good, but why does a homeowner need to know the r-value of a material? Is it really that important? It’s extremely important – it’s how you know if your windows, doors, siding, attic insulation, roof or garage doors are energy efficient. If part of your home exterior isn’t energy efficient, then it isn’t doing its job correctly.

Below, we’ll show you the major benefits of having energy efficiency products. Believe it or not, you’ll find yourself living more comfortable and with a fatter wallet.

Make Your Home More Comfortable

If you have more energy efficient windows, doors, siding, attic insulation, roof and garage doors, you’ll be able to trap heated and cooled air in your home. It also prevents outside temperatures from getting into your home.

make your home more comfortable

This gives you great control over your home’s temperature. Your home will be more comfortable and you won’t have to worry about feeling the outside weather at all. This is incredibly important for Midwest homeowners who experience all sorts of harsh and unpredictable weather.

Save Money on Your Energy Bills

Making your home more comfortable isn’t the only thing energy efficient products do. You’ll also save money on your energy bills.

How in the world can new windows, doors or siding have any effect on your energy bills? Since you’re trapping heated and cooled air in your home, your furnace and air conditioner won’t have to work as hard to reach your desired temperature.

Since they don’t have to work as hard, they won’t be using as much power. As a result, your electric and heating bills will be much lower.

Prevents Rugs and Furniture From Fading

Another benefit that comes along with energy efficient windows and door glass is preventing your furniture and floors from fading. Believe it or not, your windows and glass play a major role in maintaining the luster of your floor and belongings.

How is that possible? Simple! If you get energy efficient replacement windows and door glass, along with having an excellent r-value, they’ll also have low-e windows. The “e” stands for emission. That means they prevent UV rays from getting into your home.

prevent your furniture from fading

The light from UV rays isn’t only harmful in large doses to humans, but to your belongings as well. Fabrics and hardwood especially will fade if they’re over exposed to UV rays. Having low-e windows allows you to enjoy the natural light of the outside without worrying about the condition of your floors and furniture.

Find Windows and Doors With a Good R-Value

Making sure your windows and doors have a good r-value and are energy efficient is crucial for your home. It can be the difference between living comfortably and suffering through the Midwest weather.

It can also be the difference between having a beautiful looking home and losing all the color in your furniture and flooring. If you don’t have the right replacement windows and door glass, harmful UV rays can fade your belongings.

If you need energy efficient windows and doors that are guaranteed to have a great r-value, get a free quote from Feldco now!

Share this article:


Get started with

*View our privacy policy

Or call us at 1-866-4FELDCO®
or visit one of our locations.


holiday decoration on home

Unleash Your Creativity with Festive Decorations for Your Holiday Home Exterior!

Get Ready to Deck the Halls: Unleash Your Creativity with ...

Exterior Home Remodeling in South Bend: Top Trends for 2024

Exterior Home Remodeling in South Bend: Top Trends for 2024 ...
Halloween decorations on front doors

Halloween Decorations for Your Home: Transforming Your Exterior into a Spooky Wonderland

Halloween Decorations for Your Home: Spook Up Your Exterior Halloween ...

How to Prevent Raccoons From Getting in Your Siding

How to Prevent Raccoons From Getting in Your Siding Raccoons ...
living room with casement windows

What is the Difference Between Casement and Crank Windows?

What is the Difference Between Casement and Crank Windows? Deciding ...

Book Today and Save!

Over 500,000 homeowners have trusted Feldco with their windows, siding and doors. Click the button below and we’ll get started on your quote!