I'm about to rebuild the entry to our house, and I found a nice (un-framed) entry door at a recycled building materials store. While I know how to deal with all of the door-related aspects, I'm looking for help on some windows surrounding the door.

I want to place sidelights next to each side of the door, and a series of small (1'x1') transom-ish windows up above, everything stationary/non-venting. It appears it should be possible to get some double-pane tempered glass from a local glass place, and then simply frame it in with some cedar; perhaps with some silicone on the exterior to keep it water-tight. (Provided I create appropriate rough opening framing, pick up the load from the door properly, and so on.)

Is there anything I'm missing? I've seen it as a construction technique in various houses, older and newer, but I can't seem to find any reference to it on the 'net, however unlikely that seems. It sure would save a tremendous amount of money, versus buying legitimate pre-assembled windows.