The differences between a built-in closet and a walk-in aren’t that different from a built-in wardrobe and a walk-in closet. It’s fairly simple—a walk-in closet is a closet you can physically enter, stand in, and walk around in. A built-in (whether wardrobe or closet) is more akin to covered shelves installed into a recess in the wall. Another big difference is walk-in closets almost always have traditional full-size doors, while built-ins either have no doors or use sliding doors.

If you have a bathroom closet with movable shelves, you can place them at virtually any spacing that works for you. Useful measurements between shelves in the working, or middle, section can be 10 to 16 inches for towels or linens. Lower or higher shelving could be up to 24 inches between shelves to store lesser-used or bulky items or boxes. 

You may need a building permit to add a closet, depending on the size and kind of work required to install it. The most likely scenario requiring a permit involves changing the structure of the house and performing electrical work for closet lighting. A permit can cost between $100 and $450. If you’re installing a smaller reach-in closet, a permit may not be required, but always check with your local municipality and consult a closet designer or builder.

Custom furniture can provide more efficient storage and maximize resources.