What You Need to Know About Replacing Windows in an Old House

If the windows in your old home are drafty, damaged, or difficult to open, you can save yourself a lot of frustration—and save on your energy bill, too—by replacing them. But if you live in a historic home with original wood windows, that decision becomes more complicated. To help you decide how to tackle this fundamental project, read on.

Should You Restore Them Instead?

If your windows are vinyl or metal and they’re significantly rusted or warped, replace them. But if you have solid wood windows, especially ones with historic and aesthetic value, consider restoring your old windows instead (at an average cost of $358 each). The original antique windows in older homes were often crafted from durable old-growth woods, so they’re often worth salvaging if possible. Plus, by going the restoration route, you’ll hew to your home’s historic aesthetic.

To determine which updates your windows need, ask your local window company, window repair specialist, or carpenter for an estimate. They might suggest any of the following:

• Freeing up painted-shut upper sashes
• Repainting or staining frames
• Replacing broken parts such as glass panes, sash cords, and hardware
• Repairing rotted or damaged sashes
• Adding storm windows. Acting like ad-hoc air chambers between existing windows and home exteriors, these typically run $240–$900 each, including installation. Although the upfront cost is relatively high, storm windows can save you 10%–30% on heating and cooling costs.

What to Consider When Replacing

Keep these tips in mind if you decide to replace your windows.

Follow Regulations

If you live in a historic home, you might need to follow certain architectural requirements. For instance, you may be asked to use building materials authentic to the time period when your home was constructed. Check with your local municipality for details.

Respect Your Home’s Aesthetic

Choose windows that complement your home’s original architecture. For example, Colonials typically feature double-hung windows with flat or contoured 6-over-1 grids, while Cape Cods often sport bay or large double hung windows.

Look for Energy-Efficient Features

Many original windows in older homes are single pane—not ideal when it comes to energy savings. When upgrading, look for windows with two or three panes, a low air infiltration rate, and built-in weather-stripping and barriers such as low-emittance (low-e) coatings. According to The U.S. Department of Energy, windows with low-e coatings usually cost about 10%–15% more than regular windows but reduce energy loss by 30%–50%.

Determine The Level of Replacement You Need

Photo: Andreas von Einsiedel / Corbis Documentary / Getty Images

You have a few options, depending on the condition of your existing windows. Here’s a rundown, ranging from the most to the least involved and pricey:

• Full-Frame Replacement Windows: If your existing frames, sills, and jambs are rotted or out of square, you’ll need to go this route. These windows feature complete frames with head jambs, side jambs, and sills. To put them in, your local window installer will need to expose window openings down to the rough framing.

• Insert Replacement Windows: If your window frames are sound and square, consider retrofitting. These fully assembled, ready-to-install windows, which range from $300–$1,500 each, slip into existing openings and are fastened to existing side jambs.
• Sash Replacement Kits: Go this lower-priced route if you only need to replace your sashes—not the frames or panes.

Choose the Right Size Windows

Careful, precise measuring is essential when it comes to ordering replacement windows. In most cases, you’ll want your window company or carpenter to measure the width, height, and depth of each opening. To ensure you get the right fit, be prepared to order custom windows. After all, most older homes feature window openings larger or smaller than today’s standard window sizes.

Hire a Pro

Installing new windows can be a challenging and time-consuming task. Plus, it’s critical that installation be correct, to make sure your windows work properly, save energy, and last. Installation by a window company or qualified contractor may also be required in order to get the most coverage under a manufacturer’s warranty. For all these reasons, it’s usually worth hiring a professional when it’s time to replace your windows.