the growshelter from brooklyn-based xlxs is this year's winner of the schuykill environmental education center's sustainable design/build competition. The shells of the GrowShelter are embedded into a 100 x 100 sq. foot space within the Schuylkill Center for Environmental Education, a 350-acre nature preserve near Philadelphia. Each shell is made out of lime mortar, which is 80% more environmentally friendly than regular mortar, formed around a reinforced frame, and embedded into a mixture of mud, seeds, nuts, and water. 18 species of Philadelphia native plants and flowers, along with birdseed ingredients, like peanuts, sunflower seeds, and corn, are planted in the growing layer of the shelter. that is thinking outside of the box!