Mirvac has promised to give first homebuyers first chance to buy 60 new flats at a Sydney Olympic Park apartment project as NSW struggles to ease concerns over housing affordability.

The first time buyers will be given a fast track to buy 60 of the lowest priced apartments - priced between $575,000 to $749,000 - when the project launches, with just 5 per cent deposit, half the group's usual requirement.