Sydney units could outperform those in other capitals over the next decade as affordability worsens and new approvals shrink, after lagging the capital gains made in Melbourne’s unit market over the past two decades.

Sydney is already recording the most significant value differential between the median house and units value, with houses attracting a record high premium of 67.8 per cent over units based on the median value in December 2023, according to Tim Lawless, CoreLogic research director.