People using the recently released financial details of the Carterton Events Centre as ammunition to discredit Martinborough's Waihinga Centre are not "comparing apples with apples", says South Wairarapa mayor Adrienne Staples.
A report tabled at last month's Carterton District Council meeting detailed how the council had underestimated construction costs for the Carterton Events Centre and overestimated what income it would bring in.
The Times-Age has received letters to the editor suggesting the $5.1 million Waihinga Centre project would likely have similar cost blowouts.
Earlier this year South Wairarapa District Council gave the project the green light, voting to press ahead with stage one, despite an opposing petition from more than 700 ratepayers.
Mrs Staples said CDC's figure of running the Carterton Events Centre also included "a lot of other things added into that total cost".
"The first thing people need to understand is when Carterton are talking about their costs it's not just strictly operating costs."
The cost of running the library, additional staff hired to manage the centre and a "sizeable chunk of depreciation" had been factored in to CDC's figure, Mrs Staples said.
"I don't think for one moment they are comparing apples with apples. And I don't see it as any sort of detriment to our Waihinga Centre project."
The CDC report showed the Carterton Events Centre, which opened in 2011, was bringing in revenue of about $65,000 a year as opposed to the $90,000 initially estimated.
It also said running costs were "significantly higher" than what was proposed in 2005. The original feasibility study for the centre estimated running costs to be $461,782 annually, however the total cost is about $1.5 million. The building cost had been estimated at $1.9 million.
That was without the addition of the auditorium, which was not in the original plans and which significantly added to the cost, bringing the final figure to $6 million.
South Wairarapa District Council chief executive Paul Crimp said he was confident there would not be any cost blowouts with the Waihinga Centre project.
"We have completed a significant amount of due diligence on the design and build costs, and also the ongoing operating and maintenance requirements."
Mr Crimp said operating costs to the project related to facilities that SWDC already ran and paid operating costs for, including Martinborough Library.
He said he did not anticipate a noticeable increase in these costs.
"The Waihinga structure is larger than the current facilities, however the majority of that increase in size is due to housing the toy library, Plunket, and iSite who will be contributing to the running costs in any event," Mr Crimp said. "The new structure will also be much more energy efficient and by using modern materials maintenance costs are minimised. So, while we are undertaking a large development, our cost structures in terms of operations and maintenance will not increase to any great extent, as the majority of the facilities already exist in one form or another."
Mr Crimp said a significant amount of the project's funding is coming from under-utilised assets, such as land and buildings that are no longer required, thus lowering the net cost of construction.
He said the estimated maintenance costs for the Waihinga Centre during a 30-year period were $26,000 a year.
"As we are already paying for maintenance costs for the existing town hall and some maintenance costs for the library, as this is leased, the rates impact will be negligible."
Mr Crimp said the two town's event centres were "very different in nature" and were not easily comparable.