The average age of first-time buyers is now 29 - ranging from 28 in the North to 32 in the South.
The Council of Mortgage Lenders estimates 64% of first-time buyers required financial help from parents or relatives in the third quarter of 2011, against 31% in mid-2005.
Helen Adams, at the website FirstRungNow.com, says: "Never has the North-South divide been quite so marked. The fact that 75% of areas in the North are affordable compared with just 5% in the South and none in London, speaks volumes.
"Those in the South face long and expensive commutes which make it impossible to save that vital deposit - it's hard to see any light at the end of their tunnel.
"The only options are buying with friends or family or more likely, getting help from parents or in the form of government schemes."
Another problem for first-time buyers in 2012 is the return of stamp duty; nearly four in 10 first-time buyers avoided stamp duty as a consequence of the temporary increase in the starting threshold from £125,000 to £250,000.
After March 31, some 38% more first-time buyers - and 43% in total - will be hit by stamp duty again.
Martin Ellis, Halifax housing economist, says: "Housing affordability for those looking to get on to the property ladder for the first time improved significantly in recent years, largely as a result of the fall in prices since 2007. Nevertheless, conditions for potential first-time buyers remain tough."