I think you are going to need to explain that better

Okay I'll try. You know how sliding glass patio doors have one stationary unit and one slider? We're talking about using several stationary units from sliding glass doors as the windows. Actually, they don't have to be sliders, just not the operable door of a door set. Apparently they're standard sized and mass produced, thus cheaper. Did that make better sense?

What are you going to use for a frame, the 2 panels (stationary and operator) are in one frame, how do you intend to install a fixed or stationary panel only? Also they would have tempered glass in them due to the fact that they are made as part of a door unit so I don't know why or how they would be cheaper than fixed windows. Standard size does not mean mass produced and cheaper by any means.

How do you plan on attaching them to frame? Door panels aren't made to use as windows. Were you just planning on putting them in the opening and thenframing it out with wood stops? If so, that's a really bad idea because you will have a very high air infiltration rate, water penetration and the caulf will contantly be cracking due to the movement of the door in the opening.

You twisted it a little as to what you heard. Here is the lowdown. If you have windows that require tempered glass, you will realize significant savings by using standard tempered door panels instead. As an example, a common sized lite for a 6068 patio door is 34" x 76". If you use that piece of glass in a fixed window frame, your window would be approximately 36" wide by 78" high.
If you don't require tempered glass, the cost savings are not as great but there are some advantages to having the tempered glass even if code doesn't require it.

that's genius, I'm looking to use exterior steel french doors as sunroom windows. Is that do-able?

When we built our sunroom, we used sliders instead of windows. Then in the spring and fall we can open the one side and have almost a screen porch.

I found a place that makes french doors and can provide different casement styles, so I am hoping I can make this happen.

Did anyone ever do this and can you comment on how it went? Thinking of doing something similar in our house. We have an area with French doors and want matching windows on each side. The window quote was astronomical so I inquired about fixed French door panels. Not only are they cheaper, but they will be identical to the french doors, just will be fixed in place. Thought this was a good solution and would love to hear takes on this from anyone that has done it or has thoughts.

hey, did you ever figure out a way to use door slabs as windows? I have the same idea but my contractor doesn't think it will work. he thinks that it will leak.

Hi - Yes! We used "Fixed Slabs" and it looks fantastic. It really provides a very uniform and modern look because the flanking windows have the exact same look as the doors. We did not want the expense of accordion style doors so this was the right look for us.

Thanks so much for the update! what area of the country are you in? I'm in Boston do I deal a lot with cold and snow sitting on the outside sills. Also, could you send a picture of the outside so I can see how they mounted it? Thx again!!!