There are concerns that some streets in parts of the special character suburbs, such as Mt Eden, Grey Lynn and Herne Bay, have been excluded from special character status.
Other suburbs, like Westmere, have extensive groupings of pre-1944 bungalows that currently have no character protection.
Council heritage manager Noel Reardon said it was a "big ask' to assess houses in the pre-1944 areas over the next three years.
He said the council had assessed five areas this year - Balmoral, Otahuhu, Onehunga, Mangere, Mt Roskill, saying it took time and resources to carry out the task.
The council had four staff on the assessment process and used consultant historians, urban designers, natural heritage professionals. Maori input was also used.
"Brisbane took 10 years to a do a similar exercise," Mr Reardon said.
The council also voted against a recommendation from officers to exclude Housing New Zealand from the pre-1944 demolition control.
An amendment from councillor Cathy Casey gained broad support. She said Housing New Zealand should play by "our rules".
Unitary Plan manager John Duguid said figures from Housing New Zealand showed that 25 per cent of its housing stock in Auckland was older than 1963. The council did not know how many of those were older than 1944, he said.
The pre-1944 demolition control applies to areas settled before 1944, not individual houses, such as farm houses.
The draft Unitary Plan includes 66 new items to be added to the heritage schedule.
