My master bedroom has no built-in closet. Should I purchase an armoire or have a new closet installed?
The problem with a built-in closet is that it's immobile and typically the clothes are hidden; today's swag is okay to have on display.
And I wouldn't be willing to give up square footage in my master bedroom. Consequently, I would opt for an armoire that can be moved around or even out of the house if and when you sell.
Most armoires are about four feet in width and usually come in pieces so they can be disassembled for ease of movement. I prefer a linen press that has a lower set of drawers and two doors above (and can also be repurposed as a bar down the road).
If you do go for a built-in, you will require 24 inches in depth for a coat hanger to properly fit; be sure to measure the length of your shirts and jackets so the rod is placed at the correct height.