A business that makes furniture in Milford and ships it from Bridgeport has found an innovative use for cardboard.

What goes out the back door as recyclable trash at Go Greenly Frozen Yogurt in New Haven comes in the front door across the street at Chairigami as fresh building material for furniture.

Zach Rotholz calls his New Haven storefront his cardboard lab. The business owner, environmentalist and furniture designer first brainstormed his Chairigami idea four years ago as part of his senior mechanical engineering project at Yale University.

Since then, Rotholz has cut, folded, bent and assembled everything from sofas to rocking chairs. He says the idea is that the furniture will be reused as something else in the future, instead of winding up in a landfill or elsewhere.

The cardboard used by Chairigami is made in Massachusetts, and the pieces are folded and cut in a precision shop in Milford. Some of the cardboard sheets are made of 70 percent recycled materials, Rotholz says.

Chairigami will be moving all of its sales online in September.