Carisbrook Stadium Trust chairman Malcolm Farry said last night that meant the trust would have to go back to the market to try to negotiate a more acceptable price, something he said had been done before, successfully, during the building process.
The latest report from the stadium stakeholders group, set up to oversee the project, noted key issues the project faced, with cost issues among them.
The report will be discussed by the Dunedin City Council finance and strategy committee on Monday.
Mr Farry said keeping costs to budget was an ongoing process but the stadium was still on time and on budget.
The report said a recommendation to use a single, local main contractor for carpentry was not acceptable, and any potential overrun would be "offset against current letting gains".
Asked about the issue, Mr Farry said that meant if the tender did end up over budget, it could be made up by possible savings in other areas, but he hoped re-tendering the carpentry could result in it being within the budget.
The tender might be put out under a different format, and the issue was "no criticism of parties that tendered".
The tender would not necessarily have to be let outside Otago, as there was "a whole variety of options" for the tendering process.
Asked how the budget was a concern if there was a guaranteed maximum price contract with Hawkins Construction, Mr Farry said the trust was working hard to make sure the project stayed on budget, and Hawkins got the profit margin it expected.
If the project came in under budget, the trust would pick up a share of the savings.
Another issue listed under cost was turf "re-strengthening", with a product called "Grass Master" available as a risk mitigation strategy for the stadium's turf.
Dunedin Venues Management Ltd chief executive David Davies said Grass Master was a plastic thread that could be inserted in the turf, around which the roots of natural grass would grow.
High use of the stadium would "flog the living daylights" out of the turf, but the reinforcement meant the surface could be used, for instance, for up to 90 games a year, rather than the 30 to 35 games grass could take.
"We would like to use the stadium as many times as we can."
The technology helped form "the best surface you can get", Mr Davies said.
Asked about that issue, Mr Farry said the council had resolved the first use of any money from savings in other areas should be for turf reinforcement.
He understood its cost was about $700,000, but he was yet to be convinced it was necessary, and no decision had been made.
"There's differing opinions on its value, he said.
