"Seven storeys above ground is the maximum that people are prepared to drive up."
Mr Parkes said nine storeys would also impact quite significantly on the neighbours.
"We are trying to be a good neighbour here."
The council voted 6-5 in favour of going up an extra two levels, with councillor Terry Molloy backing the additional 110 car parks. He said the extra parking spaces would take the council through to the time when the city had transitioned to fewer single-occupant cars and more people were cycling and catching buses.
"It will take at least 10 years and this will see us through."
The building which planned to open in December next year would also feature a high-spec cycle hub for 250 cyclists including showers, lockers, charging points for e-bikes and cycle maintenance facilities. There would be no impact on rates.
Quizzed by councillor Max Mason about the extra two levels, Mr Parks reiterated that casual car park users would not drive up nine floors, but there was the potential for the council's vehicle fleet to use the 9th level.
Mr Mason said going higher brought down the cost of the extra car parks from $47,000 for each carpark to $33,000 each.
"That is quite a bargain, it will never be cheaper."
Councillor Steve Morris said an "11-storey monster" would be less attractive to a purchaser - the future ownership of the council's car parks was due to be considered as part its 2018-28 Long Term Plan debate.
He warned that the debt train was coming and spending the additional $4.5m could be at the expense of projects like the Memorial Park to Strand walkway, the Coronation Pier rebuild, and cycleways.
Councillor Gail McIntosh said she was not unaware of what was coming. "But this is what we do, we make tough calls."
Councillor Larry Baldock said the council should not crystal ball gaze too much.
"Two more floors is too much of a risk. I can't see people driving nine storeys up. It will be a pretty dizzy journey...providing more capacity on that site will bite us badly."
Ms McIntosh disagreed. "Going up nine floors is a nothing."
She said it was a better financial deal and there was very little difference in debt.
Councillor Kelvin Clout said the nine level building was not farsighted enough. "Do it once and do it right."
Councillors who favoured 11-level parking building: Kelvin Clout, Bill Grainger, Max Mason, Gail McIntosh, Terry Molloy and Catherine Stewart
Those who opposed: Mayor Greg Brownless and Larry Baldock, Leanne Brown, Rick Curach and Steve Morris.
Other works associated with car park building
- Potential mid-block closure of Hamilton St
- Covered walkway from basement car park to new civic heart development
- An initial 12 charging points for electric cars
