Buy land deeds for #00,000 Gold and then visit a builder NPC and you can plan a home from various sets and models/examples and the builder constructs it within 5 game weeks for about #,000,000 Gold.
Your dream home on a Mountain top for #,#00,000 Gold. Complete with Sheep pen.
Lovely.

Or not...

Could be hard to implement, mabey if it simply had "empty lot" preset places where you could build the house, but most likely not anywhere you want it.

Houses and buildings were my favorite mods to make in Morrowind...partly b/c I am not good at scripting and the dialogue/quest systems were a nightmare.

My favorite was an underground castle with different rooms to display armor, weapons, books, and magic/alchemy type stuff. The 4 rooms were so that you would have enough space and not run into lag when all of it was together. They were all connected to the main room at the entrance so it was quick to get around.

For bonus stuff I had a bedroom, kitchen, dining hall, throne room and a large dungeon...that was my favorite part. I used slave pods to cage one of all the coolest creatures in the game + expansions.

It was all 6th house architecture execpt the dungeon which was daedric. The whole place was littered with strong monsters so only a high level person could clear it out and make it his home.