Caring for Historic Windows

In a new monthly column, Christopher W. Closs, an expert with Maine Preservation, answers your questions about maintaining antique and vintage homes.

Q: Our 1923 shingled house in Cape Elizabeth still has its original wooden windows. I love them, but they’re not energy efficient. Some window companies claim I’ll save a fortune with vinyl replacements. What should I do?

– P. Brown, Cape Elizabeth, ME

A: This is a question that we at Maine Preservation hear all too often. And the answer is easy: Keep those historic wooden windows — please! Well-maintained wooden sash windows fitted with metal weather stripping and storm panels can perform just as well as expensive, vinyl replacement units. (By the way, they’re called “replacements” for a reason; they’re not designed to be repaired, only discarded and replaced.)

Here’s a three-step guide to caring for your old windows:

1. First, make sure you have no cracked panes, and that your paint and glazing compound is in good shape. Glazing is the putty-like substance applied around the outside edges of windowpanes to form an air- and watertight seal. Cracked or missing glazing needs to be replaced. We recommend acrylic glazing because it dries fast. You can apply it with a putty knife or caulking gun over a primed surface. Click here to learn how.

2. Next, repair or install storm windows and weather stripping. Storm panels create dead air space between your window and the exterior, blocking cold air from entering in the winter. There are even interior storm panels that slip into place from inside your home — no ladder required! If you don’t want to deal with the chore of removing storm panels in the summer and replacing them in the fall, consider installing color-matched, narrow-frame exterior storm windows with screens and two-part interior storm windows that slide up and down, just like regular double-hungs.

Weather stripping seals gaps around windows and doors, and helps reduce energy bills. You can buy plastic, felt, or foam varieties, but at Maine Preservation we like the results delivered by bronze or zinc products, which are composed of thin pieces of material that interlock for a durable, effective weatherproof seal. You can find local companies that install metal weather stripping online, or contact us at for more resources.

3. Lastly, don’t forget to secure your sash lock. Yes, it’s a security device, but it also pulls the upper and lower window sashes together making a tight seal that further reduces air infiltration.

Salesmen may try to convince you that vinyl replacement units are better than period windows, but this is simply not the case. Wood windows 60 years and older are typically made of old-growth timber. Not only are they dense and remarkably durable, they can be disassembled and repaired. Most importantly, they’re part of what gives your house its historic character.

Finally, I’d like to clear up one more myth about old windows. If properly cared for (see above), they are not drafty. As you learned in physics class, “heat is drawn to cold.” So when you, with a body temperature of 98.6 degrees, walk past any window on a frigid day, you’ll sense a chill as the icy pane draws heat from your body. So please don’t blame your historic window for that shiver — it’s thermodynamics at work!

Pictured Above: The 1782 Hugh McCulloch House in Kennebunkport sports 12 historic windows on the front and is currently available for purchase through Maine Preservation.

Christopher W. Closs is field service advisor for Maine Preservation, the only nonprofit historic preservation group working to preserve and protect treasured places across the state of Maine. Closs holds a Master’s Degree in Historic Preservation from the University of Vermont and is skilled in restoration carpentry and stone masonry. You can email additional questions to and find more helpful information at