On average, building a custom or built-in closet costs around $2,100. However, the total price can range from as little as $500 for a simple DIY project to $6,000 or more for a large, high-end custom closet. Most projects typically fall between $1,500 and $5,000.

The final cost depends on several factors, including the closet's size, type, materials, and features. Here is a general cost breakdown by closet type:

• Reach-in closet: $500 to $1,500

• Walk-in closet: $750 to $5,000

• Wardrobe: $2,000 to $6,000 or more

Choosing a prefabricated closet system is generally less expensive than a fully custom build. The scope of design and construction services will also significantly impact the price.

You can modernize an old-looking closet by just painting it, but beyond that, consider electric elements like recessed or accent lighting. If this is a large and deep closet, you can consider adding an island to the middle or a nice ottoman on a rug. Luxury closets will have even more items, like felt-lined drawers for watches and jewelry, in-wall safes, electronic shoe storage, or a tablet catalog of their items.

If you’re on a tight budget, the least expensive material you can buy for DIY closet shelves is chipboard, a.k.a. particle board. This inexpensive material is made from a pulp of sawdust, resin, and glue that’s pressed together under high temperature and pressure. As you can imagine, it’s not very sturdy and might buckle under your blue jean collection, so you should only use it if you’re storing very light items. 

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.