Costs on Snøhetta and Spence's Turner Centre in Margate have rocketed threefold even before contractors have started on site.
The scheme - described by Turner scholar Andrew Wilton as a 'hideous globule' - won planning permission at the end of February, but critics are concerned that project costs have jumped from an estimated £7 million to nearly £20 million.
Locals have called for an audit to be carried out before it goes any further. 'We are certainly not opposed to the idea of a Turner Centre, ' Margate Society chairman Steve Villette told the AJ. 'But we are stunned by the cost hikes.
'I'd like to see a breakdown of the budget and understand quite how this has happened. There are rumours that Kent County Council has asked for the costs to be trimmed. I hope they have.
'It's just a shame we couldn't get a Turner Centre for the £7 million that was originally budgeted for the project, 'Villette added.
A spokeswoman for the centre reluctantly admitted that the cost for the 'overall project' had reached £19.5 million, but insisted that the building itself - 'without heating and air-conditioning' - remained at about £11 million.
And she said that Kent County Council is still seeking funding for the project. 'There is still a long way to go, but we hope the centre is complete by 2007, ' she added.
Project architect Rob Greenwood said he could not comment as he wanted to 'steer clear of speculation about costs'.