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Brian Kelsey is a TV personality and licensed contractor. See more of his home improvement adventures on his website, The Making of a Home Renovation Show.

Brian Kelsey

Many of us are drawn to the beauty and charm of an old house. Unfortunately with old homes (and many not-so-old homes) come old windows.

Old windows may give a home distinct character, but they can also leak lots of energy. In recent years, window replacements have come a long way in terms of energy efficiency. Replacing your windows can save you a ton of money on heating and cooling.

What should you look for when shopping for a replacement window? Energy efficiency comes first, so look for low-E glass with with double- or even triple-glazing for maximum insulation. As for the window frame, though wood is available, most homeowners lean towards wood clad window replacements. Wood clad is wood covered in a layer of super-protective aluminum. (PVC clad is another option, but I don't recommend it.)

Also, make sure to keep your window replacement consistent with the rest of the house; if most of your windows are 6-over-6 or 12-over-12 double-hungs for example, stick with that style. There is no eyesore more painful than a big casement window stuck in the middle of 4 double-hungs.

Here, I will be replacing a drafty old 6-over-6 double-hung window with an efficient and authentic-looking 12-over-12 window (this type of window is a staple of antique homes, and rarely used in new construction). The original window was single pane and drafty; the new window is state-of-the-art -- and super energy-efficient -- all the while retaining the charm of the classic 12-over-12 style.

Replacement windows are meant to slide right into an existing window opening, jam and all, with no alteration needed; this is the type of job I'll be demonstrating. Sash replacement windows are just that; replacing the window sash only. A full-frame replacement is the most expensive option and involves pulling out the old window in its entirety down to the studs and replacing everything. If you are unsure how to go about replacing your window, have a window professional come by and give you your options.

SKILL LEVEL: Intermediate/Advanced

TIME: 4 hours,feedConfig,localizationConfig,entry&id=880247&pid=880246&uts=1273686759

How to Install a Replacement Window

Here's what you'll need to have on hand before you get started:

Replacement window: The average price range for a wood clad window is about $400 to $600
Tape measure
Utility knife
Caulk gun
Latex caulk
Putty knife
Screw gun
Minimal expanding foam insulation
Wood filler
Foam brush
2" screws

How to Install a Replacement Window

Here's a diagram of a double-hung window. Every part of the window has its own specific name -- and there are lots of parts!

How to Install a Replacement Window

One of the most important parts of the job is measuring the window opening. You'll need to measure the width across the top, middle, and bottom, jamb to jamb. You'll use the smallest of these measurements.

Next measure the height from the windowsill, up to the top jam at the left, right and middle; again use the smallest measurement.

You will also need to make sure your window opening is square (all sides are at a perfect 90-degree angle to each other); do this by measuring from inside corner to inside corner on both corners. The two measurements should be equal. Most likely they won't; but as long as they are within about a ¼" you are ok – you'll be able to make that up with shims (slivers of wood). If the numbers are way off, you will have to replace the whole window, down to the studs. When you order your window, give them the exact measurements, and they will size it accordingly (about ¼" smaller all around).

How to Install a Replacement Window

Once you receive your replacement window, it's time to get started on pulling out the old one.

(First, turn on some music; preferably on the loud side. It makes the job just that much more fun.)

Now, pry off the window stops using a putty knife; they hold the window in place.

How to Install a Replacement Window

If the windows are caulked or painted s stuck, use a utility knife to cut them free.

How to Install a Replacement Window

Pull out the bottom sash first.

How to Install a Replacement Window

Then pull out the top sash. Because the bottom sash juts out in front of the top one, the sashes must be removed in this order.

How to Install a Replacement Window

Using a chisel and utility knife, clear out any remaining caulk, wood debris or other obstructions from the channels inside the casing.

How to Install a Replacement Window

Fill any holes with exterior wood putty. You can use your fingers to apply the putty. Let it dry before moving on to the next step.

How to Install a Replacement Window

Prime the whole inside of frame, using your foam brush and exterior primer for maximum weather protection. Some professionals recommend oil-based primer, but water-based primer works just fine. It dries quickly and doesn't give off fumes.

How to Install a Replacement Window


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