Glass and Mirrors - Altering Alum. Patio Doors

I have several old stock Noranda 5/8" ins. glass aluminum sliding doors in one room which are not energy efficient at all & I have a very high heating bill if I wish to use room in winter. When I placed rigid insulation against lower half of the units my heating use dropped considerably & comfort level rose. I would like to replace doors but too expensive. I would like to cut units to about 30" high (or nearest stock window size) and build an insulated wall below. I can cut frame and raise threshold very easily to the new sill hight but not sure if the aluminum sash units can be cut and re-assembled. Is this feasable? I realize you can't cut the ins. glass, they will have to be ordered of course. Its the sash framing i'm concerned with.

The insulating glass units will be impossible to cut.

interesting way to solve your problem but do able,but also a lot of work to do it right.Sure you want to do this? it would be easier to build you wall up and order new windows.

MOST sliding glass door frames are screwed together and the screw spline goes the length of the jamb. You could remove the frame ( you will need to cut your siding back to get to the nail fin ) take it apart and cut to fit, then order new glass like you said. But for a few more bucks you could have new windows.

I would buy new windows and not waste my time and money on refabbing old frames that are not energy efficient.

The sliders consist of a 72"x80" extruded alum. wall frame with two 36"x80" movable sash. The extruded wall frame can be easily cut in place and existing threshold moved up to new sill hgt. I don't see any problem here. There is no flange to be cut, masonry type installation. It's the "movable" sash members I'm concerned about. Can these sash members be cut and re-assembled. I assume that the sash are somewhat dismantled in the operation of replacing the glass anyway, couldn't the vertical "sash" members be cut and top member re-attached to the new height. I would want to cut them to a stock glass size & order new glass to fit. I built the addition 25 yrs. ago when heating costs were not such an issue.

best way to tell this is to just take 1 apart, look and see where the screw spline is ( top and bottom or sides ) then refab accordingly.Meaning you may need to redrill access holes for screws if the spline is top and bottom.

Of corse, you will need to cut top and bottom so you can still use the latch.

oops never really answered, Yes you can cut them in MOST cases.
without seeing them I can't be %100 sure, but I'm darn sure you can.
where there is a will there is a way.

There is no "stock size glass" for what you're trying to do. glasman2 advice to buy a new window is the way to go. We are in the business and I'm sure glasman2 will agree, trying to cut those doors is something we would find next to impossible to do.

Thanks glasman2 - I'll take one apart to investigate. Have nothing to lose as I will be replacing them anyway (one way or another) I just needed the advice if I was wasting my time trying this approach. I have been in the building business also but never ran across this type of situation. I'm retired now and my time is cheap. I like the looks of the units as they match the windows of the rest of the house in color and profile. All replacement units I've seen seem so boxy as they have to "pan" out and around the existing built-in frame. It's hard to explain here but a total replacement would be impractical. Thanks again.