You can't do everything with Green Construction.  Here are 5 technologies we did not and really could not use that make sense in buildings.  They are perfect for many designs, but could not be used because of the architectural style of our home, and other considerations noted.

Cold Climate Heat Pump or Halowell Low Temperature Heat Pump
EuroSlate Roofing Shingles
Gray Water Reuse System
Green/Vegetative Roofs
PowerPipe Hot Water Heat Recovery System
Radiant Paint
Structurally Insulated Panels

Follow the links to learn more about these great products and techniques.

SIP Panels: Structurally Insulated Panels are prefabricated wall or roof sections, complete with insulation.  They can be quickly assembled and thus save time during construction.  Over half the cost of a project is labor so the time savings compensates for the slightly higher cost of SIPs.  Again, we did not use SIPs because of the curved walls in the house.  If your builder uses SIPs, chances are he is a progressive builder and understands the detail needed to build a green building. (The link takes you to Premier Building Systems a major SIPs manufacturing company in Fife, Wa and has a good explanation of the product.)

EuroSlate: This is roof tiles that looks like slate that is 70% recycled tires.  The price is comparable to conventional roofing material but has the quality look of a slate roof.  Undoubtedly, this roof will last as long as anything on the market.  Because of our roof design (curve) we could not use EuroSlate which locks together.  Ideal for most roofs.

Power Pipe: This is a copper pipe that recovers waste heat from hot water.  The hot water goes down the drain, and cool water is heated as it passes around the coil in the power pipe.  Our house was slab on grade and we would have needed a 6 foot room under the grade to accommodate the PowerPipe.  The technology can capture as much as 70% of heat in waste water.  Best suited to a home with a basement or second story shower. Really ideal for hotels and apartments complexes. 

Cold Climate Heat Pump or the Hallowell Low Temperature Heat: This is probably the most exciting new product to hit the market in many years.  The Nyles Cold Climate Heat Pump has been tested in places such as Fargo, North Dakota and shown to work at temperatures as low as 0oF.  Most heat pumps loose efficiency as temperatures fall below 32o, as performance decays to electric resistant heat, so there is real benefit in this technology.  Regrettably, the Cold Climate Heat Pump is tied up in some sort of corporate problem but Hallowell seems to have just launched (8/06) the product.  If you can buy one, this is a very cost effective alternative to the high prices option we selected of a ground sourced heat pump. This technology should be absolutely perfect for Washington state.

Green Roof: This is a vegetative roof, commonly grasses that provide insulation in the winter, cooling in the summer.  If used widely in cities, we can eliminate the heat island effect where urban areas are hotter than the suburbs and exurbs.  Green roofs need relatively flat roofs and thus, they are perfect for most commercial construction. However, they are not cheap and we decided to save money. Our house also is in the country (at this time) and the heat island consideration was modest.  

Gray Water Reuse System: Gray water is the water going down the drain that was used for bathing, washing clothes or dishes.  This water can be used either to flush toilets or irrigate lawns.  Since there are only two of us, this seemed overkill.  However, we did try and discuss a project with local government officials, because gray water used for lawn irrigation could have real benefits during the dry season.  The hurdles put up by the County Health Department (frankly, they did not want to know) made us pull away from such a system. The link is to a paper on a gray water system for landscape irrigation.

Radiant Paint: There are a couple of companies who sell an additive to paint that contains microscopic ceramic beads.  The theory is that radiant heat will hit the wall and bound back into the house, or out away from the house if the heat is from an attic space.  This product is expensive, and we could not find any independent research to verify significant benefits.  One study indicated that the benefit might be around 2%.  In fact there most studies indicate that the benefits are minimal at best.  It's cheaper to add more insulation.