Printed Farms is building and 3D printing a $3.3 million luxury horse barn, horse walker, and manure shed. When complete in August, the horse barn will be the world's largest 3D-printed building.

There will be barn space for 800 horses, and some of the land could be rented to horse owners who want to build their own barns and living quarters nearby. "It's pastoral, so the horses can be ...