What do you mean by building? I'm not sure about any ideas for any of the places currently in MD, but if you could open up a new area in the north-west past Loreroot.
Mountain holds, citadels, underground cities in complex cavern systems. An altar suspended above a gaping abyss in the heart of a mountain. Dragon cities upon lofty peaks in the far north. Abandoned ruins of an old civilization before Daniel Raven, and Jack Willow. Signs of Elf dwellings. The remnants of a race of dwarves in small villages niched into the mountains nearby their mines.
A vast maze of passes, small glens and mountain vales. I can not compare in artistic skills to any of the artists on the game, but if I get better I'll contribute as much as I can.
And I would really love to base an alliance of assasins known as the Anmaglahk in the northwestern corner of the mountains in the homeland of the elves, backed by a sheer drop down the cliffs of Insanity into the pounding surf. Of course they would have to befriend the elves and swear fealty or something first.
I'll need to do more planning on this and probably learn some coding.
It's some awesome ideas I have but I'm not sure how feasible they are. But I am seriously going to make an effort to accomplish it.