Built-ins add so much pizzazz to a room, you may forget they offer practical sources of storage, too. In this article, you'll learn how to plan, build, and install two bookcases and a window seat, but you're not limited to building only this project. If you're building around a fireplace, for example, omit the window seat. Or lengthen the shelving units and omit the base cabinet for more display space. Our modular system makes it easy to mix and match components to fit your room.