So players can build vaults now. Hooray. However, unlike most buildings, there's only one option for building a vault. The current vaults take up a fair amount of space, which is good for their tier, but how about a taller two-story tier VI vault with a smaller footprint. A wider vault for tier II might also be worth looking into. These would add more variety to player building options, and give some of the smaller plots a chance to have a vault in the area, at the cost of some extra work.