Curved Walls:
Curved walls are generally due to architectural considerations on the other side such as circular staircases or curved hallways. The curve inside the closet, whether concave or convex, makes it difficult to efficiently use the space. Squaring off the closet side of these walls during the framing process is less costly and it improves the space efficiency. 

Niches and Alcoves:
These areas may seem like a good use of space but generally are not because they usually do not allow enough space for storage. It also takes the installer more time and usually requires customized product. If you do put a niche or alcove in, make it at least 14” deep for storage and 24” deep for hanging and 24” wide. Framing across these areas squares off the useful space and the cavity can be utilized for HVAC chase-ways or a shelf stack. 

Bump-Outs:
Corners in closets framed out for HVAC ductwork (or otherwise) should be deep enough to accommodate closet components on adjacent sides, which is 14” for storage and 24” for hanging.

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