"In major cities with population growth we would expect supply to be anywhere between 12 to 24 months," Evans said.
"Most apartment projects take two to three years to build so the current undersupply will remain in the foreseeable future. Auckland's population growth, as well as banks restricting funding, is not assisting the needed supply of new apartments."
Deposits have been taken on most of the 3795 new units, which sold for an average of $1.12 million, up 12 per cent from a year ago, he said.
Last month, a study of more than 200 New Zealand industries conducted by market researchers at IBISWorld picked the top sectors set to flourish, and those forecast to decline in the next year.
Apartment construction topped the list. The multi-unit apartment and townhouse industry was forecast to grow to $1.42 billion in the 2017-18 financial year, up from $1.3b. However, not all apartment buyers settle.
In July, nine Sugartree apartments valued at about $6 million were being quietly promoted for sale, after buyers who put down deposits had either died, had a change in personal circumstances or did not have enough money.
Zoltan Moricz, senior director and head of research at real estate agents and consultants CBRE New Zealand, said in July that a record 1216 new apartments worth more than $600m would be completed this year in Auckland's CBD -- the most this decade.
Moricz said 343 new CBD units were completed between January and July, not counting suburban projects. A further 873 CBD units were under construction and due to be finished this year, Moricz said. That gives a total 1216 new units, his data showed.
In 2012 and 2014, not a single apartment was completed in Auckland, he noted.
Many new apartment blocks are being built with no, or limited, car parking due to the Unitary Plan's drive for intensification and encouraging more use of public transport.