Which word best describes a building considered to lack aesthetic judgment?

The term "tasteless" is the most fitting word to describe a building that is considered to lack aesthetic judgment. It implies a lack of sophistication or discernment in design choices, suggesting that the building fails to meet accepted standards of beauty and artistry. When something is described as tasteless, it generally conveys that it may be garish, poorly designed, or simply unattractive in a way that reflects a disregard for elegant or pleasing aesthetics.

Considering the context of the other choices, "elegant" conveys a sense of style and grace, which conflicts with the idea of lacking aesthetic judgment. "Nondescript" implies something that is boring or has no distinctive qualities, which could describe a building that lacks personality but doesn't necessarily indicate poor taste. "Unsightly" suggests that something is ugly or unpleasant to look at, which could be related, but it doesn't specifically capture the lack of judgment in design that "tasteless" does. Thus, "tasteless" is the most precise choice to effectively characterize a building with a distinct absence of aesthetic sensibility.