Homeowner insulates basement in a 1915 house, but one old window keeps letting in cold air

A resident preparing for a fourth winter in their 111-year-old house turned to fellow century home owners for help after basement insulation failed to eliminate a stubborn draft.

With one wooden window still letting in cold air, they hoped to find a seasonal fix and took to Reddit's r/CenturyHomes forum for advice.

Here's what to know

In the Reddit thread, the homeowner explained that the three other basement windows had already been replaced with vinyl, leaving just one old wooden window that lets in cold air.

The original poster added, "Our basement gets colder than it should and last year we had the floor joists and basement ceiling insulated. … My question is how would one go about weather proofing the window and sealed crawl space?"

Commenters streamed into the thread to add their suggestions. One of the top comments read, "Look at indow windows interior storms. Yes, that's spelled correctly. Much nicer than most of what's been suggested so far."

Another commenter suggested, "Start with the frame, not the glass. Caulk and weatherstrip the window perimeter, then add the shrink film as a seasonal inner pane. For the sealed crawlspace, fiberglass alone will still leak air, so cover it with a sealed rigid board or plywood panel, foamed around the edges. That stops the draft instead of just slowing it."

A third wrote, "Many people here [are] suggesting glass block to replace the windows. That's fine if you will never use it as a living space. The basement in our 1924 house is almost entirely finished, and I really really wish the previous owners had not put in glass block. On nice days I would like to open the windows to bring in fresh air, and I can't."

When another century homeowner suggested using rigid foam "cut to fit snug inside the frame," the OP responded, writing, "Really smart! Thanks, I think I'll go with this solve."

Where can I learn more?

Drafty windows and other leaky openings can keep a home cold even after insulation is added. These stories cover a simple window test, air sealing advice, and winter fixes for problem windows, skylights, and a window air conditioner.

• A two-minute paper test can help identify drafty windows before calling a heating professional.

• A first-time homeowner feeling cold pouring through skylights received two inexpensive fixes from commenters.

• A Midwest homeowner unable to remove a garage window air conditioner received winter weatherization advice.

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