"[But] before the Government starts demanding a set of standards from the private sector, we have to get our own house in order. I am quite concerned about some of the quality of housing that Housing NZ has."
Dr Wills' expert group on child poverty proposed a warrant of fitness as one of its six "immediate priorities" because of research showing that high rates of poverty-related child illnesses such as respiratory infections could be reduced by making houses warmer and dry.
"The current regulatory arrangements are inadequate and have not been amended since 1947," it said.
Dr Smith said Housing NZ had made "a huge step forward" by insulating all state houses by late last year - "but we still have a way to go in other areas of the quality".
He said any new regulation was "more likely to be a graduated standard rather than just a bare minimum".
"The first step will be setting some bare minimum about whether a property is suitable to be rented, and Housing NZ has done some good work there, but I also want some measures that allow me to monitor the improvements in the standard."
He said the measure was likely to combine elements of a healthy housing index developed by Otago University, the Green Building Council's Homestar rating, and quality standards being applied by Housing NZ.
"It's early days. This is policy work I'm looking at," he said. "I would hope to make some progress on the question of a housing warrant of fitness scheme this year."
Professor Philippa Howden-Chapman of Otago University, who helped develop the healthy housing index and was part of Dr Wills' expert group, said state houses had already been upgraded and any remaining faults should not delay regulatory action.
"In the work we have done, private rental housing is on average in poorer condition than Housing NZ houses, which are in poorer condition than home ownership."
What healthy housing index measures
• Structural soundness
• Adequate services
• Warmth and dryness
• Safety
• Protection from external hazards
