Auckland mayor Len Brown says he expects amendments to the city's 30-year plan to include changes to building heights in coastal areas.
But Mr Brown does not believe that will automatically lead to the city sprawling at the edges.
The first round of public feedback and discussion on the Unitary Plan winds up on Friday.
The council estimates that 12,000 people have attended public meetings and about 6000 have given feedback.
A draft version of the plan is expected to be ready by October for a formal round of public submissions.
Critics of the rulebook for how the city will grow say it allows higher-rise housing across too much of the city and too much of suburbia is zoned for multi-storeyed housing.
Some doubt forecasts of an extra 1 million residents in 30 years, although Auckland has previously outstripped even high-growth projections.
Mr Brown told Radio New Zealand's Morning Report programme that predictions of Auckland's growth have been underestimated in the past, and it's critical the current council does not do the same.
"We're the fastest growing city in Australasia," he says.
Deputy mayor Penny Hulse says changes are likely including lower building heights in some local areas.
"The areas that have caused the most conflict, I think we can make quite a lot of change. The key is, though, we're still going to go a little bit out and a little bit up - it's where we do this that's going to be the key issue for us."
A US transport and land-use consultant says the Auckland plan is not aggressive enough and will in fact reduce urban development from its present level.
John Mauro from Seattle says at the moment 80% of development happens in urban areas, but the plan proposes to lower that to about 70%.
He told Morning Report that means there will be more opening up of green spaces and the city will eventually sprawl outwards.
A youth-led organisation says its main concern with the plan lies with the amount of urban sprawl it envisages.
Generation Zero has 3000 members who broadly support the principles of the draft Unitary Plan vision for a more compact city, and it favours the development of suburbs such as Mt Eden, Newmarket and Ponsonby.
The group says young people don't want more suburbs filled with big box retailers and endless streets of similiar housing.