Share house living is growing as the rental market remains tight and high living costs prod home owners to rent out spare rooms.
Online share accommodation site Flatmates has recorded an 18.8 per cent increase in new listings since this time last year, but even with that boost, demand for rooms is still dramatically outpacing supply.
Community manager of the platform, Claudia Conley, said in many suburbs, there were more than 100 people looking for every property listed.
Listings in popular beach suburbs in Sydney's east were recording huge interest, with 344 seekers in Tamarama where there was only one home available. In Bronte, 846 people were hoping to rent one of the four rooms going.
Ms Conley said the increased interest in share housing, represented by a record-breaking 212,000 active members on the platform in January, was partly fuelled by normal domestic and overseas migration trends in the summer months.
"The university semester is about to start, many members are looking to move for new jobs, most leases are renewed at this time of year and migration is high as people flock to Australia for that quintessential Aussie summer experience," she said.
But she said the record-breaking activity on the platform was also underpinned by the high cost of living and rental crisis pushing more people towards share accommodation.
Per Capita executive director Emma Dawson said more people were having to share house to bring rental costs down at the same time as more homeowners were having to rent a spare room.
Vacancy rates have been extremely low, pushing rents higher. Ms Dawson said this was forcing more people into sharehousing or staying in these arrangements for longer, particularly young couples who were simultaneously struggling to buy.
At the same time, mortgage holders had been hit with several interest rate rises and many were hoping to recoup those costs by renting out a room.
"The two things are leading to a spike in multiple occupant dwellings," she told AAP.
She said this was partly unwinding the trend to smaller household formations during the pandemic when space became a priority.
"And then, as immigration has returned, and that rental vacancy crunch has really hit, we're seeing more people having to share houses in order to bring their rental costs down, and also more homeowners having to rent out a spare room in order to make their mortgage payments."
The latest Statement of Monetary Policy from the Reserve Bank noted that while average household size had increased in capital cities over the past year, it remained well below pre-pandemic levels.
Ms Dawson said residents per household were still falling short of pre-pandemic levels but said forming larger households would not solve affordability problems at the source.
"No number of homeowners renting out a spare room is going to touch the sides of the rental and housing crisis in this country," she said.
Part of the problem was a lack of well-located and suitable supply, including social housing, which can take pressure off the private market.
There were also policy options on the demand side, she said, including removing tax concessions that distort the market.
