LEGISLATORS in cities across the United States, alarmed at the spread of "McMansions", are trying to contain the size of American houses.

Inspired by concerns that communities are disappearing and alarmed by the environmental costs, planners have drawn up measures to ensure new homes stay within a footprint that is proportionate to the plot size.

Since 1973 the median size of a new home in the US has grown from 142 square metres to 208 square metres. At the same time, the number of people per household has fallen from 3.1 to 2.6.