It's so simple: rounded boards with notches, and they connect together without any tools or nails or anything. They look a lot like huge notched popsicle sticks, painted in primary colors, now faded and chipped from fifteen years of use. When you connect them (just slide the boards together at the notches) they start to resemble things, cool things like a fortress or a playhouse, a lemonade stand or a tower. The same boards, put together, taken apart, put together again into something completely different.
Our product designer, David Archer, and his two young sons first saw the set that inspired his in Copenhagen when he spent a sabbatical there fifteen years ago. It was in a public park where it was kept in a shed and hauled out every morning by the park attendant. While his boys played with it, David studied it, and built his own in his basement when he returned to Chicago. His sons continued to enjoy it -- especially when they had friends over for sleepovers -- until they left for college.
In April 2014 Jill is introduced to David's Copenhagen-inspired 'popsicle sticks'. That same day she spends a few hours in the back yard building some things herself, with the help of David and his son Max. At some point that afternoon she is struck by an idea that she can't shake off: lots of kids might have fun with this. They should at least have the opportunity. She posted some pictures on Facebook and the response was overwhelmingly excited. Unsolicited offers to buy it came in, but instead of selling that first set, Jill and David spent the summer and fall of 2014 improving on the design of that original design.
That first set was solid as a rock, made with 1" marine-grade plywood and about 6 coats of house paint. In other words: heavy. The boards had to be lighter to be a viable kids' playhouse. They were also limited in width, so you couldn't build something wider than four feet in any direction. Unless you used the extra long boards (nick-named "threezees" because they had three notches), which were beyond heavy for kids to play with.
You find yourself visualizing potential outcomes, and making use of muscle-power to build it. The pieces connect by sliding into the slots of other pieces -- no hardware or tools whatsoever. It was fun, the kind of fun where you feel smarter, stronger, and a wee bit exhausted after.