Half of those expecting to buy their first home say they will need help from their parents.
The financial pressure on prospective first-time buyers is also evident from survey findings that show it is now taking longer to save a home deposit.
More than half of those who hope to be buyers have been saving for two years, according to a survey.
This is up from 40pc of potential buyers who reported a year earlier that they were saving for two years.
The cost of property and a lack of supply are the main challenges for prospective first-time buyers, research commissioned by Bank of Ireland has found.
Half of those surveyed said the cost of property was the biggest challenge facing them.
More than half of first-time buyers surveyed said they will need help from family to secure their mortgage.
Some 51pc of those surveyed are likely to receive a financial gift towards a deposit, and a third are planning to move in with their parents to increase the amount they can save, although the high cost of property is making saving more difficult.
The research found over three-quarters of first-time buyers have a deposit savings plan in place.
But the length of time it takes to save is increasing, with 51pc saving for two years or more, up 10pc since 2017.
For the vast majority, a house is the preferred choice rather than an apartment.
The survey was conducted by Red C among prospective first-time buyers aged 25 to 45.
The amount of money first-time buyers save each month increased over the past year from an average of €461 in 2018 to €538 a month this year.
More than half of first-time buyers said they were unaware of the Government help-to-buy incentive, despite the potential of the scheme to save them up to €20,000. This lack of awareness comes despite 44pc of first-time buyers looking to build or buy a new home.
Head of mortgages at Bank of Ireland Brian Vaughan said: "Buying your first home is a challenging process and the survey makes it clear most have a deposit savings plan in place, with the average amount being saved increasing year on year."
He said it was concerning that many were unaware of the Government incentives that could save them thousands.