In most real estate markets, buyer behaviour follows a predictable pattern — when prices rise in one suburb, demand spills over into the next most affordable area nearby. But not always.
According to Ray White Group Chief Economist Nerida Conisbee, some high-end locations buck this trend entirely.
These rare markets, dubbed “fortress suburbs,” remain immune to the usual spillover effect, maintaining price growth dominance regardless of affordability gaps with neighbouring suburbs.
“These ‘fortress suburbs’ have unique characteristics that make them irreplaceable to their buyers, creating defensive barriers that adjacent suburbs cannot breach,” Ms Conisbee said.
Drawing from 2022–2025 median house price data across 1,339 suburbs in Sydney, Melbourne, Brisbane, Adelaide, Perth, Canberra, and Darwin, the analysis compared expensive suburbs with nearby, more affordable areas, typically priced 20–50 per cent lower, to identify spillover trends.
In most cases, adjacent cheaper suburbs outperformed their wealthier neighbours, gaining between 0.1–10.4% more annually.
However, just seven suburbs nationwide consistently defied this rule.
Five of them are in Sydney:
- Bellevue Hill
- Mosman
- Double Bay
- Dover Heights
- Woollahra
The others are Toorak in Melbourne and North Adelaide in Adelaide.
While Sydney’s eastern fortress suburbs are well-known for their harbourfront prestige, North Adelaide stands out for its geographical uniqueness.
Situated on a peninsula surrounded by the River Torrens and vast parklands, it benefits from a heritage grid layout and scenic isolation that can’t be replicated, even by adjacent Prospect, where homes are 39% cheaper.
“This demonstrates that fortress status isn’t just about harbourfront mansions – it’s about any location with truly irreplaceable geographic and social characteristics,” said Ms Conisbee.
The analysis draws parallels with the concept of “fortress assets” in commercial real estate, such as shopping centres or prime office towers, which were once seen as disruption-proof due to their community function and irreplaceability.
However, Ms Conisbee notes that even fortress status isn’t permanent.
As the shift to online retail disrupted shopping centres, the same risks apply to residential property unless core, unreplicable traits are preserved.
So what defines a true fortress suburb?
According to the report, these locations share three defining traits:
- Irreplaceable location
- Established prestige
- Buyers who prioritise status over price
In Sydney, that means harbour views, luxury retail, heritage charm and peninsula positioning.
In Melbourne, Toorak maintains its status through generational wealth and architectural prestige.
And in Adelaide, North Adelaide’s physical isolation and historic value make it immune to price-driven buyer migration.
“When buyers can afford any suburb in Australia, adjacent alternatives offering only price savings provide no meaningful advantage,” said Ms Conisbee.
“These fortress suburbs maintain their market position because their core attributes – location, heritage, and social status – cannot be purchased elsewhere.”
For real estate professionals, understanding the fortress suburb phenomenon reinforces the importance of recognising non-price-driven buyer motivations, especially in high-end markets where prestige, heritage and social capital often outweigh price.
