Council staff and Mayor Dave Cull also have reservations about the test, but said it was the only way to determine whether the assessment tool developed was practical.
The tool, a warrant of fitness (Wof) checklist to be filled in by a trained assessor - in Dunedin's case assessors from outside the council - will be tested on 25 Dunedin rental properties in January and February.
The location of the properties will not be made public, nor will the results have any ramifications for owners, but the information will be fed back to a national group, including several major councils, which is developing a national standard for housing.
In a report to the DCC, council staff said their reservations included the pass/fail nature of the test - specifically what constituted a fail.
They said many Dunedin rental properties would likely fail the Wof in its present form and identified at least 10 criteria rentals might fail on.
The voluntary nature of the Wof was less likely to capture substandard housing and a phased process would be more realistic than the proposed enforcement method of allowing a period for items to be remedied before reassessment.
Policy analyst Anne Gray and events and community developer manager Rebecca Williams said the concerns had been raised with the national group and the feeling there was that such concerns were ''the very reason the field test should go ahead as it, in itself, would help define the ultimate Wof'''.
Concerns were expected to be highlighted during the Wof test phase and approaches reviewed.
They noted housing in other areas of the country taking part in the test could also potentially fail and that they did not expect Dunedin results to stand out from other cities'. However, Cr Calvert said the fact the test was being done, even though it was acknowledged it was flawed, would not inspire confidence in landlords, and would get even less buy-in if it continued to be ''fiddled with'' as time went on.
Although she applauded the desire to ensure Dunedin homes were warm and dry, she did not believe the rental Wof was the best way to achieve that.
The idea of assessing properties was good, but the fail/pass concept would discourage landlords and the level of detail in the 31 criteria of the present test went too far. It was ''nonsense'' if the goal was simply to ensure rental properties were warm and dry.
''I think this is a case where perfect is the enemy of good.''
Although it was good the assessment tool was being tested to highlight flaws, the council had to return to a focus on making houses dry and warm and felt an A to D rating system would be more encouraging for landlords.
''If you keep the rules light and add inspiration to achieve at a higher level, then you achieve much more with people. People will voluntarily do things they would never want to do if you come at them with a big stick.''
If landlords did all the things the Wof required, it would be at the expense of things they really needed to do to make houses warm and dry, she said.
The Wof would cost a lot to administer and, if not legislated for, would leave the council open to risk from challenges from landlords.
As the owner of some student housing in Dunedin, Cr Calvert would not volunteer to be part of the trial because the test was so flawed.
Mrs Williams said staff were confident they would find landlords to take part in the field test, and had a first meeting with landlords yesterday. She said testing the test was an early step in a long process.
Mr Cull said he started pushing a year ago for something to happen in Dunedin about minimum standards for insulation, heating and weather-tightness in rental housing because it was affecting the city's economy and community.
He said there was a possibility Cr Calvert's concerns were justified, but the tool had to be tested before the council jumped to any conclusions about it and
there was no guarantee the council would choose the Wof option. As a student accommodation owner, he would be comfortable with his flats undergoing assessment.
