"For many they are a blight on the American landscape. For others, they are an expression of freedom and success. Now legislators in cities across the US, alarmed at the spread of "McMansions", are trying to contain the size of American homes.

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 1,525 sq ft (142 sq metres) to 2,248 sq ft. At the same time, the number of people per household has fallen from 3.1 to 2.6. Huge mansions are a common site across the US, dotting the landscape alongside motorways in Colorado, or squeezed into tiny plots in urban areas.

But the trend has alarmed planners and conservationists. In Boulder County, Colorado, which has recently adopted measures to cap the size of new homes, houses have grown from an average of 3,900 sq ft in 1990 to 6,300 sq ft last year. Last month in Los Angeles, the city's planning commission passed a motion to restrict the size of new homes. If the city council adopts the measure it could affect 300,000 properties in the city. Similar measures have been adopted in Minneapolis and in Florida."