I agree with the studio apartment thought. I lived in one for 12 years in NYC that was only 250 square feet. Heat was provided so I have no idea the carbon footprint although it couldn't have been much. My only outside facing wall was 10 feet wide by 9 feet tall with two double pane standard issue double hung windows. In the summer I had a window unit a/c and using it as much as I wanted added roughly $20-$25 per month to my electric bill back in the mid/late 90's. Maybe 200 kw/hours per month. And cleaning was quick and easy. The only outdoor space I had was 9 blocks away in central park, but most of NYC doesn't have private outdoor space either. No one was going to do a tv show about my lifestyle (I mean really, who's going to do a tv show called "Typical NYC Apartment Living") but I really liked living there.