Urban issues - why developers prefer green field sprawl

Bill McKay talks to Kathryn about the myth of lack of land. He says sprawl is a problem in big cities and small towns, whether it is new suburbs or big box commercial developments on the outskirts. Developers and some politicians regularly call on Councils to "free up" more land for development. The reason for this is that all Councils have city or district plans that zone land and the use / activity that can take place on it eg rural or commercial or housing.