The major issue that stands in the way of green contractors is the sheer amount of materials that must go into the construction of a building. By being able to reduce the amount of materials from the start, your contractor is already going a long way toward helping preserve the environment. Doing so limits the amount of trash that ends up in the world's landfills, thus reducing the size of the footprint that any expansion leaves. In addition, using fewer supplies means that less will have to be made and bought. That saves on the front end in respect to the environmental cost of producing materials, and it also means that you'll end up saving some money, both of which are huge positives [source: EPA].