Wellington will need to find space for a lot more residents if predictions of the city's population doubling over the next 30 years come to pass.

Wellington's next city council will have a job on its hands to keep houses affordable and stop the city from bursting at the seams, with predictions its population could nearly double over the next 30 years.

Council chief executive Kevin Lavery has suggested in a pre-election report that the council's current prediction of an extra 50,000 people living in the capital by 2043 may have been grossly underestimated.

The past 15 years have seen Wellington's population jump from 169,000 to 203,000. If that trend continued, an extra 90,000 people would put down roots over the next three decades, Lavery wrote.

ROSS GIBLIN/ FAIRFAX NZ Wellington City Council chief executive Kevin Lavery says the city's expected population boom will be a challenging for the new council after October's election.

But he warned the real number could be higher still if last year was anything to go by, when population growth spiked at 2 per cent.

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"If that kind of growth is sustained for a long period of time, the city would grow by over 160,000 people over the next 30 years. All this growth means that there is greater demand for housing."

MAARTEN HOLL/ FAIRFAX NZ Wellington's suburbs may need to endure some level of housing intensification in order to cope with the expected population surge.

The average house price in Wellington has already increased about 7.5 per cent over the past year to sit at $560,000.

Wellington's physical boundaries do not look like growing. On Friday, the Local Government Commission announced it had ditched all work on merging the capital with other parts of the region, such as Porirua.

Lavery said the 15 people who find themselves sitting around the Wellington City Council table after October's election will have some big decisions to make on the supply, quality and diversity of housing in the capital.

MAARTEN HOLL/FAIRFAX NZ Wellington Mayor Celia Wade-Brown says she would prefer to see housing intensification focused on the CBD and Te Aro rather than the capital's outer suburbs.

Gollins Commercial principal Chris Gollins​, who is marketing the 386-hectare Plimmerton Farm subdivision north of Porirua, said fitting an extra 100,000 people into Wellington would be achievable, provided the city grew upwards as well as outwards.

"Most big cities around the world disposed of single houses years ago ... people who want to live in a single house will have to accept they'll need to live a bit further out [of cities]."

He believed greenfield land north of Wellington at Lincolnshire Farm, Takapu Valley and Ohariu Valley would give the capital some room to move. But accessing other greenfield areas would not be cheap, from a development perspective.

SUPPLIED Wellington City Council's chief city planner David Chick says housing intensification done the right way, coupled with sorting out the capital's transport issues, will allow it to accommodate more residents.

"There's a lot of land around the city, but there are questions about the economics of getting to it."

David Chick, the council's chief city planner, said the odds of the city's population almost doubling over the next 30 years were pretty long, given last year's population spike was probably just that.

He acknowledged Wellington had its challenges when it came to housing supply, such as being constrained by its geography and a shortage of potential greenfield developments.

BUILDING COMMUNITIES

But he was confident Wellington could find room for a lot more residents through housing intensification in the CBD and Te Aro, as well as suburbs where the town centre and transport links could accommodate it.

The danger was that developers would concentrate more on packing people in than on good design. "We're not out to generate developments and profit margins for developers. We're building communities."

Wellington Mayor Celia Wade-Brown said she believed her council had done plenty during her six years in charge to set the city up for a population boom.

It had signed off on a number of special housing areas with the Government, and was actively consulting communities in several suburbs on potential medium-density housing rules.

Establishing an Urban Development Agency this year would also help increase the city's housing stock and keep prices in check, she said. The agency will be able to buy and assemble land parcels, and partner with developers.

"When our average house price is $560,000 and the Government considers $600,000 to be affordable in Auckland, then I think our city is looking pretty good."