11/17/2014 09:00 am ET Updated Nov 25, 2014

An Architect's Tips For Turning The Living Room Into An Epic Pillow Fort

John Lund/Annabelle Breakey via Getty Images

Architect Ben Pell remembers precisely when his two kids started building pillow forts, and it began with their Lego obsession: “There’s a moment when they go from seeing objects as solid to seeing things with an interior. First, they built towers by stacking, but then they start thinking about how the men can go inside. It’s a simple function of play, but it’s a mental switch. They weren’t interested in making things they could inhabit until their Lego men could inhabit things.”

Of course, it helps when your dad designs stuff like this for a living. Here are tips on pillow fort building that Pell has learned the hard way: By giving his kids free reign over the living room.

Read more on Fatherly