The research found that the share of renters leaving the family home has been steadily declining across the UK since 2015.
Back then, first-time renters made up 6.1% of all tenants who moved into a new home equating to 71,860 new rented households in England.
During the first five months of 2023, that figure has dropped to 4.6% which will equate to around 43,280 new rented households in England this year.
Aneisha Beveridge, head of research at Hamptons, said: “Around 105,000 missing renters are relying on the hotel of Mum and Dad.
“The number of first-time renters has been steadily falling since 2015, pushed down by the spiralling cost of living and record-breaking rental growth which has stretched affordability to the edge of its limits.
“Young adults are staying at home for longer in order to save up, with some skipping the rental market entirely and going on to purchase a home instead.”
While the share of tenants leaving the family home has risen in the North over the last year, tougher affordability has kept a cap on the number of would-be tenants doing the same in the South of England.
So far this year, those leaving the parental home made up 5.4% of all renters in the North of England, compared to 3.7% of those renting in the South of England, which includes London, East Anglia, the South East and the South West.
Hamptons’ data says the average rent on a newly-let home in the UK rose 9.1% year-on-year in May.
Beveridge added: “Average rents across Great Britain have risen 47% over the last decade, underperforming house price growth of 69% over the same period.
“However, the key issue is that over half of that rental growth has occurred within the last four years – and this has come at a time when household incomes are under pressure from other rising costs.”