July 20, 2026 — 11:30amThe share of Sydney suburbs where over-65s outnumber those aged under 20 has trebled during the past two decades as the city’s population ages and the high cost of housing locks young families out of many neighbourhoods.The population of those aged over 65 outstripped those aged up to 19 in 54 Sydney neighbourhoods in 2024, new analysis of Bureau of Statistics population data shows. That compares with only 18 neighbourhoods in 2001.Potts Point-Woolloomooloo in the inner city had the highest population balance in favour of seniors, with 1889 more people aged over-65 than under 20. It was one of several inner-city neighbourhoods where seniors outnumber those up to 19 years; others included Double Bay-Darling point (114 more people aged over 65), Darlinghurst (636 more) and Surry Hills (481 more).Affluent neighbourhoods north of the harbour also had a large population balance in favour of seniors, including Neutral Bay-Kirribilli (1127 more aged over 65 years than aged 0-19), North Sydney-Lavender Bay (508 more) and Avalon-Palm Beach (505 more).Parts of the Central Coast also had a high share of seniors, especially Umina-Booker Bay-Patonga (1693 more aged over 65 years than under 20) and Erina-Green Point (1203 more).Among the reasons for this outnumbering is the ageing of the population. In the mid-1970s, about one in 12 Australians was aged over 65, but that has now climbed to one in six. The share of over-65s nationally is forecast to reach one in four by the 2060s.Terry Rawnsley, a KPMG urban economist who analysed the latest local area population figures, said the high cost of housing has also played a role, especially in well-located Sydney suburbs.“It also comes down to housing affordability,” he said. “Families with young children just can’t get their foot in the property door in many suburbs.”Fewer births have also been a factor. Sydney’s fertility rate – the number of expected births per woman – has fallen by nearly 20 per cent in the past decade to a historic low of 1.44.The age profile of some neighbourhoods has shifted rapidly over the past two decades.In the Cronulla-Kurnell-Bundeena area, for instance, under-20s outnumbered over-65s by 1179 in 2001. But by 2024 that had reversed and seniors outnumbered those aged 0–19 years by 863. In Mosman North in 20221 there were 480 more under-20s than over-65s; by 2024 there were 458 more aged over 65 than under 20.The cost of housing has been a factor in the growing number of Sydney suburbs where seniors outnumber those aged 0-19.