yes it could work that way. I thing it can be done by overlapping an ambient occlusion rendered bulding with concrete or grunge layers as multiply in order to add some texture and then fill it with vegetation, people and add some also textured sky. I saw this kind of presentations at some swiss students or in some swiss offices added to work presentations (one example is Zumthor at conference in Pairs). If done properly the renderings can look really neat
