A furniture unit includes at least one substrate having an upper surface, a lower surface, a proximal peripheral surface, a distal peripheral surface, a first seam, and a second seam. The lower surface is opposite the upper surface. The proximal peripheral surface extends from the upper surface to the lower surface. The distal peripheral surface is opposite the proximal peripheral surface and extends from the upper surface to the lower surface. The second seam is spaced apart from the first seam. The first and second seams extend in a direction parallel to the proximal peripheral surface. The proximal peripheral surface engages the lower surface such that the substrate defines a first hollow support.