Some of the reasons for unaffordable housing

New research has placed the blame for the nation's housing-affordability crisis squarely on state and federal governments, saying they have ignored the real cause: poor planning.

A for sale sign is displayed in front of a house in Sydney Source: AAP

The Grattan Institute research centre says leaders' efforts have actually exacerbated the problem.

It even suggests reducing the level of immigration as a possible last resort.