* Housing Minister Nick Smith said a major barrier to greenfield development was infrastructure cost.
* The councils eligible to access the $1 billion infrastructure fund are Auckland, Hamilton, Tauranga, Christchurch and Queenstown - cities predicted to have more than 10 per cent population growth in the next 10 years.
* Charging an extra rate on unimproved land as a disincentive to land banking is also a possibility.
* The fund will own or finance the infrastructure until the councils receive rates revenue from the new houses.