CARING CONSTRUCTION Ken Stevens and Karl Miller work on the Habitat for Humanity house on Greenhouse Avenue in Randolph. The new building will be home to a family of four once it is completed next year. Using expanded polystyrene boards as forms, the building will be made of highly-insulated concreteÑa construction phenomenon that is just catching on in the U.S. that is very highly energy efficient. (Herald / Tim Calabro)