The gap between the first and second rungs on the housing ladder has more than doubled over the last decade, according to bank research.

The average additional capital needed by "second steppers" is now £18,462, more than double the £8597 required 10 years ago.

A recent Bank of Scotland report found two-thirds (65%) of aspiring second steppers were unable to move in the past 12 months.

New research by the bank suggests that a shortfall or lack of a deposit is a key challenge for almost a third (31%). The majority hope to use savings or equity (65%) to fund the move but one in seven (14%) are contemplating turning to their parents.

Almost half (46%) of people got money from friends or family towards a deposit on their first property, although the vast majority (90%) got money from their parents.

The average first-time buyer received £13,000 from family and friends for their first home, and some are now looking for a further £9063 to trade up.

Out of the first-time homeowners involved in the research, 68% live in flats and 14% live in terraces, with the average flat valued at £106,587. Over half hope to move to a three-bedroom house. The average price for a semi-detached house is £125,029.

Since 2001 the average cost of moving furniture and other associated transfer costs has shot up by 69%, from £4125 in 2001 to £6972 in 2011.

Laurence Mann, head of mortgages at the Bank of Scotland, said: "We already know that second steppers in Scotland 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 attention and 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."