Rental properties will have to meet a set of minimum standards under rules to be unveiled by the Government next month.

The move will stop short of a full "warrant of fitness" for rentals but is aimed at ensuring all tenants have a safe and healthy home to live in, Government sources confirmed.

That is likely to include a requirement for insulation, although sources said there was still work to be done to set any standards at a practical level. It is due to be announced next month by Building and Housing Minister Nick Smith, along with an assessment of a warrant of fitness trial in state houses, and would apply to all rentals both private and public.

The signal comes in the wake of a coroner's finding last week that the death of Emma-Lita Bourne from a brain haemorrhage could partly be blamed on the poor condition of the state house she lived in. The family had been provided with a heater but could not afford to put it on.

However, a full warrant of fitness has been rejected by the Government as too difficult to police and requiring regular "rechecks" that would hike compliance costs.

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Prime Minister John Key on Monday said some of the advice the Government had seen on a warrant of fitness suggested rents would rise and it was likely some landlords would pull out of the market.

Andrew King of the Property Investors' Federation said if insulation became mandatory there should be a carrot in the form of a tax deduction for installation.

"It's very expensive to put in."

He said it was not just an issue of insulation and some tenants did not put their heating on.

But Key rejected the idea of a one-off payment for heating, instead backing current provisions including emergency assistance for those who needed it.

The Government earlier this year rejected Labour's Healthy Homes Guarantee Bill which would have required every rental home meet minimum standards of heating and insulation to ensure they were warm and dry.

It would have taken effect in about five years, as tenancies rolled over.

However, sources said the Government considered that timeframe was too short for landlords.