Secret doors aren't just in the movies. With a few tools and materials, you can build your own bookcase that doubles as a secret door into a crawlspace or attic.

There is nothing complicated about this Billy bookcase hack. Just assemble, add some moldings and components, and paint.

Possibly the most important part of the build is figuring out how to hinge all the weight a bookcase will carry. His solution was to use a set of four heavy-duty casters.