Habitat for Humanity brings families and communities in need together with volunteers and resources to build affordable, healthy, sustainable housing. The program enables families to build their own homes, with assistance and training. "Habitat's Environmental Initiative promotes cost-effective, best-practice construction methods to its U.S. affiliates, raising awareness of the environmental impacts of house building. As a result, partner families may enjoy healthier, more energy-efficient and durable housing at the lowest possible cost. Over time the initiative has been integrated into Habitat's standard education and training activities, so that affiliates are encouraged to be good house builders and good stewards of natural resources."
To finance their work in part, they operate "ReStore" home improvement centers across America that sell high quality used and surplus construction and home improvement products of all types. Indoor and outdoor lighting, home appliances, doors, windows, cabinets, counter tops, tiles, and more are sold at substantial savings. Most are donated by building supply stores, contractors, demolition crews and individuals like you. Proceeds help fund the construction of Habitat houses within the local community. My husband and I went to visit our local ReStore and found a good selection of doors (including a $50 front door exactly the same as one we had purchased at a salvage yard for $100 and was selling for $200 at a home improvement warehouse), marble bathroom tiles, some great salvage windows, and a lot more. It's worth a visit.
See their pages on Materials Conservation and their Energy Bulletins.