A San Diego Homeowner’s Guide to Energy-Efficient Windows and Doors

Homeowners in San Diego replace their windows and patio doors for a variety of reasons. They may want to reduce the amount of outside noise that comes into their home, or get rid of old windows that no longer open and close easily, or give their home a fresh, updated look. However, far and away the most common reason people choose to purchase replacement windows and doors for their San Diego home is to make it more energy efficient.

Making your home more energy efficient is a worthy goal, and certainly new windows and doors can help you do that. But you should note that some replacement windows are more energy efficient than others. Fortunately, the window industry has standardized the way in which windows are rated for energy efficiency, so you can easily compare replacement windows from different manufacturers. Unfortunately, the ratings will mean nothing to you if you don’t understand the terminology.

In this blog post, we will break down for you what the various terms and their respective ratings mean and which ones are most important for San Diego homeowners to look at.

Where Do You Find Energy Efficiency Ratings?

Energy efficiency ratings on replacement windows are fairly easy to come by. If you are shopping for windows in a store or window company’s showroom, look for the black and white label that says “Energy Performance Ratings” on it. The ratings on this label are generated by the National Fenestration Rating Council (NFRC), which is the independent organization that evaluates the performance of virtually every replacement window and door on the market.

If you are buying windows from a replacement window dealer or a contractor who doesn’t have a showroom, you can ask them for the NFRC ratings for the windows they are recommending to you. They should be able to provide them, but if they don’t have them readily available, you can always go the window manufacturer’s website and get the information. Most manufacturers have more than one series of windows, so make sure you are looking at the ratings for the windows you intend to purchase. The energy efficiency numbers can vary from series to series. Most major window manufacturers will make a more budget-friendly option that is less energy efficient than their top-of-the-line offerings.

What Do the Replacement Window Energy Performance Ratings Mean?

It would be nice for the average homeowner if the ratings were in simple terms that anyone could understand, but instead, they use terms that are unique to the window industry.

The first rating you’ll see on an NFRC label is “U-Factor.” This rating tells you how efficient a window or door is at keeping heat from escaping. In other words, a window or door with a good U-Factor rating will help keep your home warm and toasty in the winter. You’ll be able to run your heater less often, and still have your home maintain a comfortable temperature when it’s cold out. U-Factor ratings range from 0.20 to 1.20. The lower the U-Factor rating, the better the window is a keeping warm air in. While San Diego homeowners should definitely make note of a window’s U-Factor rating, it’s not the most important rating to consider, since San Diego rarely gets cold enough for homeowners to run a heater. U-Factor ratings are much more important in areas that experience harsh winters.

The second rating you’ll come across is the Solar Heat Gain Coefficient (SHGC). This number tells you how well a window or door will keep unwanted heat out of your home. SHGC numbers range from 0 to 1, with a lower number being more desirable. A window with a very low SHGC rating will do a good job of keeping your home cool in the hottest summer months and allow you to use your air conditioning far less. If you live in a home without air conditioning, windows with a low SHGC rating will keep your home more comfortable in the heat. As a San Diego homeowner, this is the rating you should be most concerned about when it comes to the energy efficiency of your new windows and doors.

The two other ratings listed on the NFRC label are Visible Transmittance (VT) and Air Leakage. These terms are a bit more self-explanatory than the other two, but you still need to know how to evaluate the ratings given in these categories.

VT refers to the amount of light that is allowed into a home through the glass. If you want a lot of natural light in your home, look for a rating close to 1. If you want less light or glare, a rating closer to 0 is best. The air leakage rating tells you how much air will be allowed in through the window or door. These ratings fall in the range of 0.1 to 0.3. The lower the number, the less drafty your new windows or doors will be.

One note on comparing the Energy Performance Ratings on windows and doors from different manufacturers: make sure you are comparing the numbers for windows and doors of similar styles. For example, compare the SHGC rating of a single hung window to that of other single hung windows.

What Do ENERGY STAR Labels Mean for Windows and Doors?

People are used to seeing ENERGY STAR labels on products like appliances, but windows and doors can also qualify for an ENERGY STAR certification. ENERGY STAR certifications for windows and doors are based on the NFRC’s ratings, and also take into account regional climate zones. If you see the blue ENERGY STAR sticker on a replacement window or door product, it means that the product has met or exceeded the Environmental Protection Agency’s (EPA) energy efficiency standards.

Upgrade for Better Energy Efficiency

Depending on the climate of your particular area of San Diego, you may not need the most energy-efficient windows and doors available. If you live in a coastal area with moderate year-round temperatures, products with modest Energy Performance Ratings may be perfectly fine for you. However, if you live farther inland, where summer temperatures can get quite high, or in a house with no air conditioning, you may want to consider windows with a better SHGC rating.

If you want superior performance, most products on the market will have certain energy efficiency upgrades you can add. For example, on the popular Bay View windows that we sell, you can add Argon Gas between the panes of their double pane windows, which will slow the transfer of heat through the window and help keep your house cooler. If only certain areas of your house seem to heat up on hot days, you can choose to only upgrade the windows in that room to save some money.

We know this is a lot of information, but we hope this guide will help you understand what some of the various ratings and terms mean when it comes to the energy efficiency of windows and doors. If you have additional questions, we are more than happy to answer them. Schedule your no-obligation appointment with one of our helpful and knowledgeable team members today.