What the source does confirm is that interest rates sitting at levels last seen in 2011 have coincided with a much larger mortgage burden nationally — average new owner-occupier loans have grown from about $282,400 in November 2011 to $731,000 by June 2026 — and that affordability pressure varies enormously by suburb and state.

REA Group's 417% Report and the National Growth Picture

By contrast, Double Bay's 219% rise and Mona Vale's 230% rise over the same 15-year window place them well behind the nation's fastest-growing pockets, even though both remain among Sydney's most expensive suburbs in absolute terms. The source does not provide a current median price for Double Bay, so no dollar-figure comparison against other eastern suburbs can be confirmed.

For broader market context, see Australian Property Forum property market data.

Background: What the Data Set Measures

Buyers and vendors assessing inner-Sydney suburbs should treat 15-year growth percentages (such as Double Bay's 219% and Mona Vale's 230%) as a measure of long-run capital appreciation since 2011, not as a proxy for current auction competition or liquidity. For guidance on contract timing, cooling-off periods in NSW remain relevant regardless of how a suburb has performed over the past 15 years.

For agents and vendors, the verifiable takeaway from REA Group's data is about long-term price trajectory rather than current market heat: suburbs that looked unaffordable in 2011 have, in some cases, more than quadrupled in value, while traditionally prestige pockets like Double Bay have grown more modestly by comparison. Any claims about current clearance rates or days on market for specific Sydney suburbs would need to be drawn from separate, suburb-level auction data not contained in this report.