Health NZ will be weighing up the two options for the new Dunedin Hospital.

An independent review has found the current plan for Dunedin Hospital, is 'probably not achievable' within its current budget of $1.88 billion.

The Government has said it either needs to scale back the project's main building or swap it out in favour of a "staged development" on the old site to keep it within the budget.

Health NZ Head of Infrastructure Delivery Blake Lepper old Mike Hosking costs have been creeping up for some time.

He says after construction began on the main outpatients building, the real costs emerged and they realised they had a problem.

Lepper says this is the problem with greenfields projects, when they were trying to do something a bit different and aspirational.

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