Probably the greenest thing we are doing for our new home is the shell of the home itself. We are not using traditional stick framing for our house; instead we are using SIP’s. SIP stands for Structurally Insulated panels. These panels are basically a sandwich of OSB (Oriented Strand Board) then a layer of Polystyrene foam core (for insulation) then a second layer of OSB. This type of system is energy efficient, cost effective and very strong.
SIP’s are prefabricated off site and brought in sections. These panels save time and money during construction. This also saves on material costs because there is very little material waste. Another great thing about SIP's are that they go up very fast, sometimes in only a few days!
Our home will use 6 5/8” SIP’s for the walls and 10” SIP’s for the roof system. Using SIP’s for the roof system allows much more usable space in the upper level of our home. Which means high vaulted ceilings in the second story. We decided not to go with ICF (Insulated Concrete Forms) which are like SIP's for your foundation. We instead elected to go with a slightly more cost effective route of having poured concrete (which is more energy efficient than a concrete block foundation). We will have a 2" layer of ridged polystyrene insulation that goes on the outside of the concrete and below the basement concrete floor.
This is how all the individual pieces of SIP have all come together.
This site also has a list of general contractors that work with SIP's if you are interested in more information or possibly building a SIP home.