There aren't enough down-to-earth, Web-based tools to help you visualize a greener home. The Green Building Studio is for architects, while Lucid Design Group's energy dashboard is found only in a slim number of buildings. Yahoo's Green House is pretty, yet it can't be personalized.
But I just wasted a fine chunk of the afternoon playing with a kids' Web site that makes a great model for what I'd like to see for adults. My Abodo is an excellent, Flash-based interface that walks you through building a virtual green home. Created in part by the British government, it's more happy-go-lucky than our Department of Energy's Energy Hog games (though not as fun as killing cows in the McDonald's Video Game that it reminded Josh of). My Abodo lets you hand-pick various parts of the house, from the flowery green roof to your own vegetable garden, while adjusting trash in the nearby dump accordingly. When you're done, you can embed your abode on a blog or other Web site, just like so below.
I'm crossing my fingers that someone might offer some freebie to bring green building down to earth for grown-ups. Google Earth (more here) and SketchUp provide so much potential for environmental imaging and modeling. Imagine if the search giant also served up an amateur architecture tool that let you design buildings online from the inside out.