Many historic homes still have their original windows. For a home to be considered historic, it must be at least 50 years old. Most fifty-year-old windows are almost certainly drafty and single-paned, making it hard for them to keep out hot and cold air. Some downriver homeowners believe that replacing historic windows with newer ones will devalue the historic look and feel of their home, as well as its value. Here’s what you should know about replacing windows in older homes.

There is a major difference between restoring and replacing old windows. The windows on many historic homes add to the exterior character and interior ambiance. Luckily, if you cannot imagine parting with your old windows, restoring them is an available option. You will have to seek out a historic window specialist. They can repair windowpanes, install weather-stripping, and even free upper sashes that may have gotten stuck over the years. Restored older windows will still block most drafts when paired with a storm window on the interior or exterior of the home.

However, not all historic windows can be restored. If any of the wood around the window has rotted, there is no turning back. Luckily, you do have the option to replace old windows with modern windows that appear historic, which also gives you the best of both worlds. This is important to maintaining the historic character of your home. Most old wood windows have a grid overlay, so if you want to maintain the character of your home, look for windows with the same feature. You may also want to work on finding windows that are the same appearance as your existing windows.

Of course, you’ll need to match the size of the existing window. Your historic home may not be the place to knock out an external wall to enlarge a small old window into a large bay window. It’s best to discuss those types of major changes with your local historic preservation committee for insights that will help honor your historic home’s best qualities.

Once you’ve decided to replace your old windows, start searching for replacement windows that will complement the style of your home. There are myriad replacement windows for old homes, but not all contractors understand how to maintain historic homes, so it is vital that you find the right window company for the job.

The cost of the job can determine your approach to whether or not you repair or replace them. Historic window restoration can cost up to $400 in materials and if you choose to get a professional to do the work, this could be another $400 per window. Replacing each window can cost you between $300 and $700 each. This assumes that the replacement is going into a structurally sound frame on the first floor. This price will easily double for a two-story home. The key is to have multiple options from reputable installers. Since you use windows every day for light, heat, and cooling, this is an area to consider all your options and their consequences when making this decision.

Be aware of the various types of replacement windows. These can vary as much as the architecture of your home. Unlike full-frame windows, which are designed for new construction, replacement windows are made to fit into existing window openings. They’re available in many standard sizes, with widths as narrow as 11 ½ inches to as wide as 68 inches. Depending on the manufacturer, they can come in wood, vinyl, fiberglass, vinyl-clad wood, and aluminum-clad wood.

There are three basic types of replacement windows: sash kits, insert replacements, and full-frame units. Sash-replacement kits give an old window frame new movable parts, including jamb liners and sash. The liners are fastened to the side jambs of the window opening, then the sash is slipped in between.

For these to work, the existing window frame must be level and square. An insert replacement window consists of a fully assembled window in a ready-to-install secondary frame. Sometimes called a pocket window, an insert replacement slips into the existing opening and is then fastened to the old side jambs. Because you’re adding new jambs and liners, the glass area will be slightly smaller than it was before.

Full-frame replacement windows are similar to inserts, except that they have a complete frame that includes head jamb, side jambs, and sill. These are the only option when the old window frame, sill, or jambs are rotted. To install these, you must strip the window opening down to its rough framing, inside and out.

The most important step in the window-replacement process happens long before installation day. It’s when you measure the dimensions of the existing window frame to make sure you order a replacement unit that’s the right size. Understanding how to correctly measure a window, whether you contact it out or do it yourself, can ensure that you will have the right fit, look, and feel once the job is completed.

The place to start is by measuring the inside width of the old window frame, jamb to jamb, in three places: across the top, middle, and bottom. Write down the smallest of the three measurements.

Next, measure the window frame’s height from the top of the sill to the underside of the head jamb in three places: at the left jamb, in the middle, and at the right. Again, record only the smallest measurement.

Check the squareness of the frame by measuring the diagonals from corner to corner. The two dimensions should be the same. If the frame is out of square by 1/4 inch or so, don’t worry; the replacement can be shimmed to fit. Anything else may require adjustments to the frame. If the frame is so out of whack that a square replacement wouldn’t look right, you’ll need a full-frame replacement.

Finally, use an angle-measuring tool to determine the slope of the sill; some replacements do come with a choice of sill angles.

If you are considering replacing the windows on your older home, AllPoint is here to help downriver homeowners. Choosing windows involves many decisions and when working with older homes, our professional expertise can prove your peace of mind.