The back door has a glass inset. I would like to remove the glass, reduce its height and replace the missing bit with a solid panel/dog door combination. Is it likely that the glass is a special composition, and can't be cut? I'll post a picture in the next post (can't seem to be sure I'll get the option on this one.)

Here's the pic:

Oh, and I'll probably need to cut into the lower panel - Westie's aren't that tall :)

Looks like insulated glass (double pane). If so, it can't be cut, and doors have to have safety glass even when the glass is higher because your door opens against a side wall (not that anyone would really know, but that's the code).

Sometimes it's cheaper to buy a used door off craigslist or a junkyard.

But you can take it out and replace the top with glass, and a wood panel in the bottom (like PT plywood) and yes, you can cut into the bottom rail.

The glass sits in a metal frame - another picture:

Looks like insulated glass (double pane). If so, it can't be cut, and doors have to have safety glass even when the glass is higher because your door opens against a side wall (not that anyone would really know, but that's the code).

Sometimes it's cheaper to buy a used door off craigslist or a junkyard.

But you can take it out and replace the top with glass, and a wood panel in the bottom (like PT plywood) and yes, you can cut into the bottom rail.

That sounds about right. I may just buy a smaller light (is that what it is called?) and modify the door that way. THD wanted nearly a thousand dollars for my pruchase and install of a different door.

Glass is tempered and cannot be cut. You can remove the glass, install the insert and regular glass. However, a replacement door with a 1/2 glass would be a lot easier.

Many people have a tough time with a replacement door that isn't set up - routing for hinges, and lining up the lockset. Difficult. A set up door would be the best if you choose that.

But I can see why modifying the door you have might be easier in some ways, and cheaper.