Here’s how they do it. By Tim McKeough All of a sudden, bunk beds seem to be everywhere: You see them in upscale beach and ski homes, as well as boutique hotels like Freehand, Moxy and Proper.

In 2012, he and his family were inspired to build and donate a bunk bed after learning there were local children who slept on the floor. “This little girl had a nest of clothes, it looked like a ...