Historic windows can be energy-efficient

By: Shannon Lee , Contributing Writer
In: Old Houses, Home Improvement Tips, Old House Musings, Technology, Historic Preservation

As any old house lover knows, those original windows are something special. The character and fit of an original window can rarely be duplicated by modern replacement windows. If the elderly windows are too far gone to be useful–if they are far too crooked due the the settlement of the house, have cracked or broken panes that can’t be replaced, or have problems with rot that are too severe to repair–then replacement is certainly better than leaving the older window in the house to deteriorate further. But if you can possibly save the original windows in a house, it is always in the best interest of preservation to do so.

Historic window. Image credit: National Park Service

But what about energy efficiency?

A tight economy means that everyone is pinching their pennies, and let’s face it: the typical historic home is an absolute nightmare when it comes to heating and cooling bills. Tax breaks and other financial incentives can make replacement windows look even more appealing. On the other hand, those historic windows are already there, and they have potential. Is it possible to make your old windows just as energy-efficient as new ones might be?

The answer is not exactly clear-cut. Replacement windows properly installed throughout the home can definitely make the place more comfortable and can likely reduce your heating and cooling bills. But keep in mind that the promised reductions in your utilities from even the best replacement windows might not be as pronounced with new windows in an older home. That’s because the construction of an older home allows the house more room to breathe. This works great until you are in the midst of a very cold winter, when drafts can come from everywhere, even from the walls themselves. Therefore, the new windows can help, but they might not help as much as you hope they will.

Making historic windows more energy-efficient

On the other hand, your old drafty windows don’t have to be that way. The windows already have a few distinct advantages; first, they were likely custom made to fit into that particular window space. That precise fit can actually make the window more efficient, as it can stop drafts from creeping in around the frame.

A good replacement weatherstripping can help seal the deal, and high-quality storm windows can also help by providing a pocket of insulating air between the inner glass and the outer window. To preserve the look of your windows even in the dead of winter, consider interior storm windows rather than external ones.

There are other tricks to consider if you are determined to keep the old windows in place. Replacing the glass in an old window with a thicker pane can help. Window glass prices are almost always much cheaper than an entire replacement, so if your frames can handle a thicker sheet of glass, it might be worth the upgrade. New weatherstripping, new paint and careful maintenance of the original wood can also contribute to greater energy efficiency and lower utility costs.

Does it pay to upgrade to replacement windows? In the long run, yes. But when money is tight and preservation is important to you, working on those old windows to make them last longer might be the best option.