Verde Property Group directors Stephen and Jody Gosling said it was planned the business would open toward the end of next year, just after the DPI take over the main building.

Ms Gosling said the ambulance station was now on a separate property title to the main building in readiness for a new use.

"We've had a chat to a couple of wineries about it," she said at a ceremony to mark a milestone in the main building's construction on Tuesday.

"It's not just to be a cellar door but to have a wine bar."

She said it was intended the business would promote wines from around the region.

Other suggested uses for the building include a cafe, restaurant and boutique brewery.

Ms Gosling said they would clean out the building in the next few months to prepare it for a business to take it over.

She said there was a September target for the DPI to move into the main building.

Ms Gosling said they were aiming to have the wine bar/cafe business open soon after that occurred.

This week's 'topping out' ceremony to mark completion of construction to the roof of the main building comes 10 months after the first sods were turned on the former base hospital site.

Ms Gosling said with construction running 21 days ahead of schedule they were on track to complete the work by the middle of next year.

A state government media release said the new building boasted green credentials which would make it energy and water efficient.

That includes the use of solar panels and electric car recharge stations.

"It has been designed and built to five star National Australian-built Energy Rating System energy and four star NABERS water ratings and a five star Greenstar rating, which will reduce operating costs and the building's impact on the local environment," it said.