Yes, adding a built-in or custom closet generally increases your home's value and makes it more attractive to potential buyers. A well-designed closet adds utility, organization, and a touch of luxury, which are appealing selling points. Most homeowners see a return on investment (ROI) of 50% to 60%; for example, a custom closet can add about $1,000 to your home's value on average. The specific ROI depends on the type, with custom walk-in closets typically providing more value than reach-in closets. However, to maximize value, ensure the closet doesn't significantly detract from the room's usable square footage. Converting an entire room into a closet can actually lower your home's value. Similarly, using overly lavish materials may not recoup their cost. A good strategy is to add a closet that takes square footage from a non-living area, such as a garage, to create a mudroom closet.

Walk-in closets are always the biggest and can easily be more than 100 square feet. Primary bedroom closets, even if not walk-ins, are the second largest category in most homes and sit between 30 and 80 square feet. Linen closets, utility closets, and built-in closets are smaller and, depending on their usage, tend to be between 10 and 50 square feet.

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.

Yes, 12-inch shelves are often considered the standard closet shelf depth for storing folded clothing, shoes, and small containers. However, if you plan to store bulky items such as blankets, baskets, or cleaning supplies, you may want to go deeper. For specialized layouts, an adjustable system can give you more flexibility.