The burden of housing costs is biting even in Australia’s wealthiest suburbs as an unprecedented one in four households nationally face mortgage stress, according to the latest in a 15-year series of analyses.

Households in Toorak and Bondi, prestigious pockets of affluence in Australia’s biggest cities, have made the list of those struggling to meet repayments amid rising costs and stagnating wages, research firm Digital Finance Analytics has found.

The firm’s principal, Martin North, said it was surprising new evidence showed that financial distress from property price surges reached beyond “the battlers and the mortgage belt” and was a “much broader and much more significant problem”.

The survey, which analyses real cash flows against mortgage repayments, finds more than 767,000 households or 23.4% are now in mortgage stress, which means they have little or no spare cash after covering costs.

This includes 32,000 that are in severe stress, meaning they cannot cover repayments from current income.

The firm predicts that almost 52,000 households will probably default on mortgages over the next year. Risk hotspots include Meadow Springs and Canning Vale in Western Australia, Derrimut and Cranbourne in Victoria, and Mackay and Pacific Pines in Queensland.

Overall, New South Wales and Victoria, whose capital cities have seen a recent surge in home prices, accounted for more than half the probable defaults (270,000) and households in mortgage distress (420,000).

North said the numbers were “an early indicator of risk in the system”.

The underlying drivers were “flat or falling wage growth”, much faster rising living costs and the likelihood mortgage interest payments would only go up.

Widespread mortgage burdens were limiting spending elsewhere and “sucking the life out of the economy”, and the problem should be addressed to head off a housing crash and its repercussions, North said.

“If we start seeing house prices slipping then this can turn into a US 2007 scenario rather quickly,” he said.

North is not alone in highlighting household vulnerability. The Reserve Bank of Australia’s financial stability review last month observed one-third of Australian borrowers had little or no mortgage “buffer”, which North said was “the first time they’ve ever admitted it”.

Finder.com last week found 57% of mortgagees could not handle a rise of $100 or more in monthly repayments.

“The surprising thing is that people in Bondi in NSW, for example, or even young affluents who have bought down in Toorak in Victoria are actually on the list [of mortgage stressed],” North said.

“The reason is they’ve bought significantly large mortgages to buy a unit, modified or brand new.

“They’ve got bigger incomes than average but essentially they are highly leveraged so they have little wiggle room and of course any incremental rate rise, because they’ve got such big mortgages, slugs them pretty heavily.”

Semi-retirees who moved to central coast NSW but are still exposed to large mortgages while their incomes were falling away were another atypical snapshot of those in financial distress, North said.

“And the people at the top, the most affluent households, the ones who’ve got really big properties, have the lifestyles to match. So again, their spare cash is not huge.

“And that point – it isn’t just the mortgage belt, it isn’t just the typical battlers who are actually exposed here – shows is a much broader, more significant problem.”