However, around 36 per cent of the homes inspected would require only a few minor fixes, estimated to cost between $50 - $150, to pass the WOF, the trial's organisers said.
Some changes were as minor as inserting batteries in smoke alarms or adjusting water temperature.
The trial WOF comes amid calls for the introduction of a standardised criteria for rental properties to meet.
It tested a range of areas that could potentially be included in a housing WOF, aiming to identify aspects such as average assessment times and how to best communicate results to landlords and tenants.
The assessment tool was developed by the NZ Green Building Council and the University of Otago, Wellington, with feedback and input from the five councils, and the Accident Compensation Corporation.
"The trial was really important so that we could gain an understanding about what is going to work for landlords, assessors and tenants. For a housing WOF to work it has to add value for the landlords and we needed to actually trial the draft WOF checklist and methodology,'' said steering groups spokeswoman Dr Julie Bennett from the University of Otago Wellington.
Auckland Mayor Len Brown said that with a third of New Zealanders living in rental accommodation, the trial underscored that a WOF system for rentals would be highly useful to prospective tenants.
"The work so far shows real progress is possible in our efforts to ensure tenants have healthy and safe homes and that landlords maintain good minimum standards.
"I look forward to the next stage where we can apply this initiative more broadly, particularly in the most vulnerable communities.''
Wellington Mayor Celia Wade-Brown said the trial highlighted that basic measures such as insulation and good heating are still lacking in many rental properties.
"Warm, dry, safe housing is a fundamental need, especially for vulnerable people, young and old. Any WOF tool will need to be accompanied by continuing support for insulation of older properties.''
The steering group will now look at the results more thoroughly and investigate ways it can refine the proposed WOF system, before presenting that information to participating councils.
About the WOF
• 144 properties inspected, aged from the 1880s to less than 10 years old, and ranging from detached houses to apartments.
• The inspection checklist looked at 31 areas.
• Average time to inspect properties was 51 minutes.
• The majority of properties (94 per cent) failed the checklist.
Top five failed criteria:
• 40 per cent of houses did not pass the water temperature check.
• 30 per cent of bedrooms did not have a working smoke alarm within 3 metres of the bedroom.
• 31 per cent of houses lacked code-compliant handrails and balustrades.
• 37 per cent of houses did not pass the check for having a fixed form of heating.
• 38 per cent of houses did not pass the security stays check.
