Funded by the Office of Aboriginal and Torres Strait Islander Health, the new extension will allow BADAC to house all its health services under one roof.

BADAC chief executive officer Karen Heap said there had been an increasing need to expand the Market St facility.

"We're all sitting on each others' laps here," Ms Heap said.

"In today's world, we're a lot more focused on health and there are a lot more services we need to provide because of our poor health and the issues we face with that."

The revamp will bring the Baarlinjan Medical Clinic and other health programs together, including dieticians, podiatry, optometry, audiology, diabetes education and chronic disease management.

Drug and alcohol and mental health programs will remain in the current building, but move next door to the new extension.

"We (currently) have health workers on one side of the building and drug and alcohol workers upstairs.

"It's not conducive to a good work method."

The medical clinic is open from Monday to Friday, 9am until 5pm, and has five part-time GPs.

Three clinic nurses are available, along with aboriginal health workers.

The clinic also includes two reception staff and two drivers, who make sure patients get to doctor or hospital appointments on time.

The S.J. Weir-constructed building will include 10 consulting and staff rooms, as well as a community hall, two reception areas for BADAC and the medical centre, multi-purpose rooms and a waiting area.

It is expected to be completed in April or May next year.