The health board is working with chosen health providers to develop a health campus on its Lakes District Hospital site. It hopes to deliver a draft plan early next year.
This week, Statistics New Zealand released projections showing Queenstown-Lakes, along with Selwyn District in Canterbury, have New Zealand's highest growth rate, 2.2%.
The increase would add more than 17,400 people to the Queenstown area by 2031.
Southern DHB finance and funding executive director Robert Mackway-Jones, through a spokeswoman, said the board's existing planning was based on an assumption of an extra 13,500 people.
However, figures could be updated, as part of the board's planning processes.
"We use the Statistics NZ medium series projections which get updated and we continually update and review our planning as part of our annual planning cycles.
"We must take into account not only the growth in the population, but also changes to the demographic composition such as the age profile."
