Thaumaturge village huts spawn in villages.
They are tall cobblestone towers with wooden floors spaced for three block high ceilings, and glass-pane windows. A ladder up the back wall leads up to a trapdoor in the roof; climbing up there reveals that the top has crenelations around the edge.
The inside levels have 3 block high rooms; and the second floor has a chest with thaumic loot, such as thaumium bars, armor, glowstone, trinkets, etc. There is also a single glowstone block, which makes an excellent start for alchemical duplication. (And better lighting than many village buildings.) The front door (wooden as usual) is a block above the ground, with a cobblestone stair beneath it.
A Thaumic Villager spawns in this building, who will trade assorted Thaumcraft related items.