Britain's private housing stock is valued at a record four trillion pounds after house prices grew by almost a tenth last year, new figures show.

Halifax, the country's largest mortgage lender, said the value of the housing stock had risen 9 percent during 2007 and more than tripled in the past decade - from 1.3 trillion pounds in 1997.

That compares to a mere 31 percent rise in the headline retail price index, a key measure of inflation, in the past 10 years.

The Halifax's latest annual housing stock review - based on figures from its house price index database and the government - also showed that equity in people's homes has surged by almost 2 trillion pounds over the past decade to stand at 2.8 trillion pounds.

The value of private housing stock was 3.4 times the outstanding mortgage debt at the end of last year, it said.

Martin Ellis, chief economist at the Halifax, said: "UK home owners have collectively accumulated an extra 2 trillion pounds of equity in their homes over the past decade as property prices have risen.

"This has significantly strengthened the household balance sheet; mortgage debt accounts for only 30 percent of the value of the UK's 4 trillion pounds-worth of housing assets."

Scotland saw the largest rise in the value of its housing stock during 2007 - up 16 percent to 247 billion pounds.

The smallest percentage increase by region was in Yorkshire & the Humber, which saw a 5 percent uplift.