ABSTRACT
Commoner’s fourth law of ecology (Commoner, 1971) should be uppermost in the minds of those trying to decide whether high density, defined as a large number of people living on a small area of land, is a good and potentially sustainable thing. The idea ‘there is no such thing as a free lunch’ suggests that there are ecological consequences to all human decisions regarding the built environment. This chapter will begin an examination of what these are for both high-density and low-density urban development in an attempt to see whether one has a significant environmental benefit over the other.
