"The valuations are based on sales for the three to six-month period prior to July 2014 so sales after this date [October] are irrelevant for the 1 July effective date," a council spokesman said. "If owners think their valuation is incorrect compared to sales prior to July 2014 ... they should exercise their objections rights."
The InDepth valuers said they compared the new valuations to October sale prices and found numerous inconsistencies.
" ... Property InDepth calculates that more than 30 per cent of the new rating valuations are already wildly wrong when compared to actual property sales throughout the city," they said.
Some properties had sold for way above the 2014 valuations, even before those new assessments were released.
"This has led to a serious situation where individual property owners having little or no idea whether their particular property is either under or over-valued," Mr McNamara warned. "There could be hundreds of thousands of dollars in financial assets potentially at stake, particularly if they're looking to sell. This alarms us because so many people, including real estate agents, rely on these RVs to value properties."
The valuers cited examples across the city in the central area, south, west and on the North Shore to illustrate their claim.
While most properties had sold for well above their new valuation, one on Epsom's Wheturangi Rd, where there are many leasehold properties, was valued at $4.2 million but sold for $2.61 million.
Other real estate industry experts have complained about the latest revaluations process with calls for the system to be reviewed or scrapped.
More than 3200 Aucklanders have now lodged objections to their CVs.
The council spokesman said the objection period was an important part of the mass appraisal process and allowed owners to have their valuations reviewed.
" ... there are bound to be some inconsistencies, but [the] revaluation process is a fair and equitable exercise."
Council rating valuations were not intended to be a guide to property values for sales. The process was an exercise used to determine rates.
CVs: $100,000 difference
Residents at an Orewa apartment block are querying valuations after neighbouring apartments of similar size and configuration received council valuation notices more than $100,000 apart.
Dave Abley, 72, who owns a unit at the three-storey Blue Water Apartments complex, said the new CV on his 130sq m pad was $850,000.
But a neighbouring third-floor 120sq m unit had been valued at $740,000. "Same floor, same age, same outlook and roughly the same size."
Meanwhile, an identical apartment to his neighbour's, but on the ground floor, had been valued at $850,000 - despite the third floor apartment having the same floor space, better outlook and superior security.
A slightly larger 140sq m apartment on the ground floor, next to the $850,000 unit, had received a $690,000 CV.
The apartments all had two bedrooms and two carparks but their land values varied between $335,000 and $430,000.
"I think it's sloppy work. It seems fairly obvious to me that apartments of the same rough size on the same floor should be, within 5 per cent, roughly the same valuation. They call it anomalies, I can only say mistakes," he said.
Mr Abley is retired and bought the apartment with his wife about seven years ago for $750,000. He had no plans to sell up and was concerned about the new valuations' impact on rates.
"Nobody is going to argue the toss if there's a $20 difference to what we pay. But if it's a $500 difference then there's something inequitable about it."
Objections
Objecting to your valuation? Lodge that before 5pm, Tuesday December 23, online or in writing and visit www.aucklandcouncil.govt.nz for more information.
