We live in Florida. To gain additional wall space we are considering using wallboard on the inside only and leaving the window as is to the outside.

What are the pros and cons?

Does this increase the mold factor?

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    What do your building codes say about a windowless room? There are sometimes light, ventilation and egress issues that the window solved, so the builder didn't solve any other way. – Harper - Reinstate Monica Feb 25 '18 at 14:59
  • I have a coworker that owns a house with a window to nowhere. It has a small "room" behind it because when they built the wall there were, reasons (she says). The window still has a (blue) curtain hanging from it... for all times sake. Now what? People see the window, and ask questions, and curtains do not match. What if the glass breaks? Does it get walled over then? How much does it impact your homes resale? Only if it was the Winchester mansion might it increase in value. Just some other considerations for you. – noybman Feb 25 '18 at 15:23
  • Closing off a window may have more long term problems than you might imagine. Things like a leaking sill or broken pane of glass may end up costing thousands from small leaks that may not be found for years. – Ed Beal Feb 26 '18 at 3:36

The pros are simply that it saves you siding repair and may add visual interest to the outside of your home. The cons are that you now have a window that you can't maintain from the inside.

I did this at my family's lake home, but it was only intended to be that way for a few months until warmer weather. We framed inside the window, insulated, and applied vapor barrier on the inside as is standard here. There were no problems at the time we removed the window and repaired the siding later that year.

Whether you have mold issues is going to depend on the quality and condition of the window. Some moisture will get behind the window due to air movement, but it shouldn't be a problem unless heavy moisture gets trapped.


Another concern is thermal shock. Walling the glass off on the inside prevents natural ventilation of the glazing - by walling it off you are trapping all the radiant heat in a small cavity. Although I've never witnessed or seen it, we are always advised by window manufacturers to use a blank off film on the inside of the windows to prevent that cavity from heating up. I'm personally never a fan of the strategy - only because as I said, the window manfacturer's don't like it. I suppose the potential is greater on south elevations than others.

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