The cost of trading up from a flat to a semi-detached home has soared in the last decade, according to a bank survey.
Many so-called second steppers are being forced to consider a loan from their parents to move up the property ladder, the Bank of Scotland said.
It says the additional capital needed to trade up is on average £21,205, compared to the £12,956 that was required 10 years ago.
The bank calculated the cost as the difference between a typical first-time buyer home (a flat priced at £111,495) and the three-bedroom semi-detached house desired by many second steppers, with a current average price of £132,700.
The research found that almost two thirds (61%) of prospective second steppers have wanted to climb up the ladder in the past 12 months but have been unable to do so, with more than half (56%) saying they have not saved enough to cover the deposit.
According to the Bank one in six (16%) of those questioned are contemplating a parental loan to plug the gap.
Laurence Mann, head of mortgages at Bank of Scotland, said: “We already know that Scotland’s second steppers face a number of tough challenges, and in many ways have been the hardest hit by the subdued housing market, so it is unsurprising that they are struggling to fund the gap needed to trade up to their preferred second home.
“Parents have long been helping to fund their children’s first home, but many are now having to provide further support as they move up the ladder.
“This indicates that these customers still need further support. To achieve a sustainable housing market we need to see movement throughout the market. If second steppers get stuck on the first rung, movement at the bottom half of the ladder comes to a standstill.”
Around 500 people were questioned for the survey carried out in January.
Labour’s housing spokeswoman Elaine Murray, said: “This is a worrying trend and shows that the SNP’s failure to prioritise housing is having a very real effect on homebuyers.
“It seems clear that the solution to this is to build more houses which, as the Scottish Government’s own figures show, they are failing to do.
“We need clarity on what will be done with the additional funding promised for housing, what support there will be for homebuyers and what will be done to encourage developers to build more houses. Without this commitment there is a very real risk that the housing market will continue to stagnate for the foreseeable future.”
A Scottish Government spokeswoman said: “We are well aware of the challenges that people face and want to continue to do all we can to help. We are working with Homes for Scotland and the Council of Mortgage Lenders to finalise a £120 million fund that will not only help people to buy their first home, but also help existing home owners who want to buy a new build home.
“In addition, a Scottish Government guarantee is supporting Homes for Scotland’s MI New Home scheme, helping credit worthy first time buyers and ‘second-steppers’ throughout much of the nation to buy a new build home. The scheme is now backed by 25 house builders and three of our leading lenders.
“Despite these tough financial times, the Scottish Government is continuing to help households and to invest in new and affordable housing.”