Hello, does anyone know the maximum possible size for fixed windows? I would like to have something about 8' wide and 9' tall... thanks

Posted By Alexis on 13 Sep 2012 10:00 PM
Hello, does anyone know the maximum possible size for fixed windows? I would like to have something about 8' wide and 9' tall... thanks

It ALL depends on the window manufacturer. Some manufacturers can make a 8x10 window all day long without any mullions. Others can only make a 4x7. With mullions one can go larger but some people don't want to obstruct their view with a mullion.

Another factor is if it will be double or triple pane? Some can only make double pane in large sizes while others can make triple pane in that same large size without any issues or having to call in the engineers.

First you need to determine WHAT KIND of window you want (fiberglass, uPVC, wood, alum/wood) and then double or triple pane and then find a manufacturer.

If you want to avoid preposterous costs, stick with this.

Most major insulated glass fabricators (PPG, Cardinal, etc) can handle units up to about 450 lbs.

2 pane weighs about 6 lbs per sq. ft.

3 pane weights about 9 lbs per sq. ft.

The other rule is 7' x 12'.  Most tempering oven are only 7' wide, thus, while raw sheets of glass come larger, they cannot get easily tempered, which is usually integral with huge glass units.

Anything wider than 7' on the short leg is often problematic and very expensive.

This is not definitive, just what I've experienced.  There are exceptions.