Considering an upgrade to your historic home? In this ongoing energy retrofit series, master craftsman Daniel Westbrook interviews industry expert Mark LaLiberte, founding partner and president of Construction Instruction. Mark has been educating the building industry on the science and physics of construction for more than 30 years, and in this series he’s sharing the benefits of constructing durable, energy-efficient, healthy homes.

Today, Daniel and Mark are chatting about historic windows and whether it is better to repair or replace them. Here are a couple of key takeaways:

Assessing historic windows

When it comes to historic windows, you should take the time to thoughtfully consider whether to do a repair or a replacement. Historic windows are incredibly beautiful, but they can become an issue if they begin allowing rain water to leak into a home. Leaks are a direct indication that something needs to be done to the window—and leaks that are not repaired can lead to rotting in the wall cavity.

Repairing vs. replacing historic windows

Unless there is a significant issue with a historic window, it might be better to repair rather than replace the window. Not only is it more sustainable (and keeps materials out of landfills), but restoring a home’s original windows also helps to preserve the home’s equilibrium. Replacing historic windows can affect the heat and moisture levels within a home and potentially cause challenges that can lead to rot, as discussed in the last energy retrofit episode.

Ways to preserve historic windows

One way to protect a historic window from further damage is to put an eyebrow over the window. This helps to redirect water away from the window and prevent it from getting excessive exposure to weather. Another approach is to add an extra layer of glass to create an additional barrier between the original historic window and the elements—known as a storm window. This is particularly helpful in the Pacific Northwest and other moderate climates.

Catch up on previous installments of our energy retrofit series on the Dunn Solutions blog, and stay tuned for more from Daniel and Mark as they continue to discuss energy retrofitting over the coming months.