I don’t personally use Google SketchUp a whole lot, having more than enough on my mind just trying to figure out Maya, but for a free modeler SketchUp is getting pretty powerful. I just saw that a company called Integrated Environmental Solutions just released a plug-in for SketchUp that allows for energy modeling, allowing the user to plot CO2 emissions, daylighting and more for the models you create. I am a huge supporter of low-cost digital tools, so this is a really good sign!
(via Inhabitat)