There is a great little gallery of rooftops posted on Flickr by one jwilly. It is a number of photographs of different roof top gardens and green spaces on top of the city. The possibilities are amazing when you consider the type of space a rooftop could be. Quite frankly I would argue that roofs are very under utilized. Look out on the roofs in the middle of most cities and all you will see is a sea of grey, blank spaces. Think about what kind of space a rooftop can be. If you open the access and add plants, you suddenly have a space that you can spend time in, a space that you want to bring other people into. Why shouldn’t every roof have a dwelling or communal space on top of i? Sure I know that most of the roofs in the city were not designed for these uses and therefore can’t handle the load, but we should be thinking that way from now on shouldn’t we?