A growing number of first-home buyers are using credit cards and personal loans to fund their deposits, a new survey has found.According to Genworth's latest Homebuyer Confidence Index, 19 per cent of first-home buyers said they used a credit card to reach the deposit target for their mortgage (up from three per cent in 2013) and 18 per cent used a personal loan for the same purpose (up from eight per cent in 2013).Genworth said the figures suggested that the big challenge for first-home buyers was getting a deposit together, not servicing the mortgage.Genworth's data lends support to a number of submissions to the Senate Standing Committee on Economics inquiry into home ownership, which said the biggest problem young people face in buying houses was the widening deposit gap.The deposit gap is the difference between a household's savings and the minimum deposit required to purchase a dwelling.The Reserve Bank pointed out that home buyers' loan servicing requirements have not changed much over time and are below recent peaks in 1990 and 2009. "Housing affordability, measured as the share of average household income required to service a loan on a median dwelling rice, has continued to cycle between 20 and 30 per cent."What has changed is that the rise in house prices has increased the size of the deposit. The RBA said lower deposit requirements have probably only partially offset this increase.Genworth said the increasing reliance on other sources of debt to fund deposits might explain why more first-home buyers were falling into the heavily indebted category: 35 per cent compared with the overall level of 23 per cent.The proportion of first-home buyers experiencing mortgage stress rose from nine per cent in March to 21 per cent in the latest survey.