I recently replaced a bunch of old, leaky aluminum windows with custom-made triple-glazed, argon-filled, low-E vinyl windows in my home, since they're quite popular in central Canada due to our harsh winters. However, after the installation, I noticed that the new windows seem significantly smaller than the old ones. The vinyl frames are thicker, which is expected, but it appears that the windows themselves are about 2 inches too short for the rough openings. The installers filled the gaps with drywall and spray foam and assured me this is normal. I'm wondering if this is really acceptable, or if I should push them to remake the windows to the proper size. We had 8 windows and a large sliding patio door replaced in this $22k project, so I want to ensure everything is perfect. Additionally, here are some pictures I took: [https://imgur.com/a/2ToYZnE](https://imgur.com/a/2ToYZnE)
3 Answers
What I see here suggests the installers may have used off-the-shelf windows instead of custom sizes for your rough openings, which could explain the size difference. They should've added shimming to fit the windows properly, so this looks like a pretty sloppy install. Good installers definitely talk to you about custom options to ensure you don’t end up with mismatched sizes. You might want to address this with them right away.
It definitely seems like someone messed up the measurements or manufacturing! I'd suggest discussing this with the installers and seeing if you can negotiate some sort of discount for the error.
That gap looks a bit excessive to me! The most concerning part would be the exterior waterproofing—seeing daylight under a window is definitely a red flag. I’d recommend checking to ensure that the installation is sealed correctly.
They did caulk it on the outside, and it seems reasonably well sealed: [https://imgur.com/a/bftNYJn](https://imgur.com/a/bftNYJn)
Yeah, we definitely don't want smaller windows! We actually had one window resized to be larger previously, and were told all of these were custom-made.