Green is certainly the way of the future and this forum offers many green building options which are fantastic. But are we being as green as we can when we are putting up buildings using green materials with machinery that still pollutes our skies? Most construction equipment used today is still powered by gasoline or diesel engines spewing noxious gases into the skies. There are equipment suppliers out here who offer alternatives. How many readers have done their homework? Electric power or Ultra Low Emissions exhaust systems are the green alternative. Do some investigating, It's good for the environment.....good for you.