"We are really wanting to look at all the elements - are people going to want to move back and live in the central business district instead of us having massive growth into the suburbs?"
The city could see a mix of intensified urban living with multi-unit apartments, as well as more suburbs.
"Or are we going to end up spreading like Auckland with all sorts of transport and other problems?"
Mr Green said the planned forum hoped to attract 200-300 people and could potentially be held in the Bay Court Exhibition Space.
Mr Tindall said SmartGrowth's current phase began in 2013 and was now at a stage where he was encouraging communication and discussion by all interested parties.
"When we're getting new developments we need to make sure we have the social infrastructure in place - the reserves, the schools, easy local access to health care, making sure connections to employment and food shopping are easy and convenient with a range of options.
"We need to think about how we grow the city and make sure it doesn't eat through the projected horticultural land."
Options included providing a diverse range of housing such as smaller town houses closer to the centre of town or employment, he said.
"It requires new ways of thinking by planners, developers and the people who are living there."
Andrew Coker, chief executive of Priority One, said SmartGrowth had been extremely important to the development of the business sector.
"Its long-term planning focus has underpinned our competitive advantages in the attraction, retention and growth of local businesses, as well as the attraction of skilled and talented people," he said.
"It has future-proofed the sub-region for ongoing growth and development, meaning we are increasingly becoming the location of choice for business relocations in New Zealand."