"Nowhere in the world do they knock down large areas of homes to intensify," the American-born businessman said.
"The Unitary Plan will make us look exactly like Los Angeles."
Emmett Hussey, a little-known contender, called the plan "stark raving mad" by not providing for infrastructure, schools, hospitals and parks.
"This will become known as Len Brown's folly," he said.
The other candidates felt likewise at the debate, hosted by the Mission Bay-Kohimarama Residents Association.
The debate was held in the Orakei ward, which has the highest rates per capita in Auckland.
This year, residential rates rose in Orakei by an average of 5.7 per cent and nearly half of households paid the maximum capped increase of 10 per cent. The average household rates bill is $3456, compared to the regional average of $2241.
Mayor Brown was quizzed about a decision last year to set the fixed annual charge at $350 when officers had recommended a higher figure of $450.
He acknowledged the $350 charge was not the answer for Orakei, saying it was set at the fairest point for the wider community, but he would not rule out raising it at some point in the future.
A low annual charge penalises high-value properties and a high charge penalises low-value properties.
Mr Palino said he would raise the annual charge to the officers' recommended level of $450 and hold rates at the level of inflation of 0.9 per cent, not the 2.9 per cent overall increase set by Mr Brown.
Stephen Berry, leader of the right-wing Affordable Auckland ticket, promised to "reduce rates", eliminate borrowing within three years and scrap spending on projects like a new theatre on the waterfront and a white water rafting facility at Manukau.
Candidates' opposition to new rulebook
Should the Unitary Plan be notified in September?
John Minto: No. The Unitary Plan is a blueprint for developers rather than community development.
Uesifili Unasa: No. One of the problems with the Unitary Plan has to do with the more disadvantaged groups in the community.
Stephen Berry: No. I support a plan where planning is as flexible as possible.
Penny Bright: No. It is not commonsense planning. What we need is a population, migration and growth strategy.
Emmett Hussey: No. If I had my way I would just flush it down the toilet.
John Palino: No. We don't want to change our character, our lifestyle and be told how we have to build a house and be left only with the colour we can paint the toilet.