Can't say I've seen a modern wood basement door but I haven't looked either. Constructed out of appropriate materials and properly maintained, I don't see why one wouldn't last a good long time.

How about trimming a basic steel door with wood?

Hi Mike,
Thanks for the feedback. That's the conclusion I reached as well. I like your idea about trimming the steel door. Do you have any ideas how I would do that? Just glue thin pieces to the steel?

I'd think it would depend on what kind of wood you're planning on using because you have to take into account wood movement. You also want to pick a wood suitable for outdoor use -- cedar, cypress, redwood, or one of the tropical hardwoods used for decking. For the large surface of the doors you could use something like marine grade plywood or T1-11. All depends on your taste and budget.

For the doors, I was thinking of something along the lines of a fence where a couple or three horizontal pieces were glued to the door surface and the vertical pieces were screwed/nailed to that.

Remember the wood will add weight to the door making it more difficult to open.

Trex?