How to Replace Your Windows for Energy and Tax Savings

There may be a window in your home that is old and drafty, or even falling apart. You may have a window that sticks, or one that you have to prop open. You’ve tried caulking, taping, driving screws into that old window but there is nothing that you can do to fix it. It is probably time to give up on fixing that old window and consider a replacement.

If you have one old window, chances are you have others. These windows can be robbing your house of energy making it hard for you keep your house at the right temperature in either summer or winter. Since windows can account for fifty percent of a home’s heating and cooling needs this wasted energy can equal a lot of wasted money on utility bills.

Now may be the best time to replace your windows for more than one reason. The weather outside is mild in most of the country, so opening up large holes in the side of your house will not create any major discomfort during the operation. Plus, the government is offering tax credits for installing energy efficient windows. These tax credits are set to expire at the end of this year so get your money while the gettin is good!

The American Recovery and Reinvestment Act of 2009 provides tax credits for homeowners who improve the energy efficiency of their homes including the installation of new windows. A window’s measure of efficiency is based on how well it keeps the outside out and the inside in. Tax credit eligible windows must meet minimum criteria of efficiency known as the U-factor and the Solar Heat Gain coefficient (SHGC). The U-Factor measures how well a window prevents heat from escaping and the rating scale ranges from .20 to 1.20. The lower the number the greater the window can resist heat flow and the better its insulating value. The Solar Heat Gain Coefficient (SHGC) measures how well a window blocks heat from the sunlight while letting in the visible light. The SHGC rating scale ranges from 0 to 1. The lower the SHGC the less solar heat can get through.

To reach tax credit levels both the U-Factor and the SHGC must be equal to or less than .30. Each window you buy should have an energy-performance label on it supplied by the National Fenestration Rating Council (NFRC). This is the only rating council recognized by the federal government when issuing tax credits. You can check out for more information on qualifying windows and how you can go about getting your credit.

The next big question is whether or not you should attack this project yourself. Watching a pro put in a window looks easy, but there is a lot more to it than meets the eye. If you have never put in a new window before, replacing all the windows in your house by yourself is asking for trouble. Replacing one window may be within the grasp of most do-it-yourselfers, but swapping out a dozen or more becomes a huge project. Where will you store the windows when you buy them? How will you dispose of all the old windows? Do you really have the time to finish the job once you start?

A seasoned professional window installer can replace all the windows in a typical home in just one or two days. They can guarantee their work and handle all the purchasing, disposal, and paperwork for permits if necessary. You may be surprised just how inexpensive it is for a pro to do the work. If your time and/or skills are limited, hiring a pro is the way to go.

When hiring a pro always get three estimates and get everything in writing. This includes start and finish dates, the brand, type, efficiency levels of the windows, and the total cost of the job. Never pay in full up front and don’t make final payment until the job is 100% complete.

If you are confident with your skills and want to give it a go yourself here is an idea of what you are in for and some things to keep in mind when replacing your own windows.

Before you begin, check with the local building codes to see what types of windows may be required, such as impact resistant or tempered glass, and whether or not you are required to pull a permit to do the work.

Essentially, when installing a replacement window you will be removing the old window sashes and the tracks they run on, leaving only the window’s jamb. The new window will slide into place from the inside and secured to the old jamb. It is important that the window fits comfortably inside this jamb.

This is where most people make mistakes. Sometimes it is hard to tell how big the new window should be, and it is necessary to delicately remove the interior trim of the window to get an accurate measurement. If you buy a window that is even slightly too small for the opening and it leaves gaps, you’ll end up with same or even worse drafts than the old window. If you buy a window that is too big for the opening the window can stick or not open at all.

If the jamb is damaged and needs to be replaced it may impact the exterior finishes of the home such as the siding or trim. This is a situation that would require more time and skill on your part, but one that a pro can easily handle.

The width of the jamb should be measured at the top, middle, and bottom. The height is also measured in three places. Take the smallest measurement of height and width and subtract ¼ inch. Ideally, this will give you the size of the replacement window you need to buy.

Replacement windows are different than new construction windows. Replacement windows are designed to slide right into the existing window jamb from the inside of the house. New construction windows come with a nailing flange and are designed to be put in from the outside of the house into an opening without a jamb.

Don’t be surprised if you have to custom order your replacement windows. This process can take a few weeks, and most custom order windows are not returnable. Never pull out the old window until you have the new window in hand. You don’t want to have a piece of plywood on your house covering a hole for a few weeks while you wait for your window to arrive.

To remove the old window you have to remove the small stop trim on the sides of the window that hold the sashes in. Remove these carefully as you will be using them again later. With the trim removed you should be able to pull the sashes out. If they are connected to the wall by a weight, cut the cord or disconnect the chain and let the weight drop into the wall. You won’t need it any longer. Remove the tracks that held the sashes in place and clean the jamb of any debris.

If all is in your favor, the new window is ready to go in. Set the bottom of the window on the jamb and tilt the window into place. Push it all the way into the opening until it is seated against the stop trim on the outside. Check that the window is sitting level in the jam. It may be necessary to use small shims to make sure the window is sitting level. Measuring the window diagonally from corner to corner and make sure the measurements are the same. This will insure the window is square and will operate properly.

Screw the window into the jamb according to the manufacturer’s specifications and seal the window into the jamb with caulk, both inside and out, to prevent drafts or leaks. Replace the small stop trim to finish the job.

It sounds easy in theory, but there are dozens of things that could pop up when replacing windows that can make the job quite challenging. Start with one window to test your skill. Don’t bite off more than you can chew and attempt to replace all your windows yourself right off the bat if you have never done it before. It could end up costing you double if you have to hire a pro to fix your mistakes.

Jason Gurskis is a licensed home improvement contractor based in Mystic Island, New Jersey dedicated to making homes more comfortable, durable, and energy efficient.