Household wealth reached £9 trillion in Great Britain between 2006 and 2008, according to a survey from the Office for National Statistics (ONS).
Its new wealth and assets survey found that 39% was in property, 39% in pension assets, 11% in financial assets and 11% in physical goods.
The average wealth of households was put at £204,500.
But while half of households owned just 9% of the wealth, the most prosperous 20% of households held 62%.
"The wealthiest area was the south-east of England, with a median household wealth of £287,900," the ONS said.
"The area with the lowest median was Scotland, with £150,600."
The ONS survey of nearly 31,000 households looked at the value of their savings, investments and assets between July 2006 and June 2008.
The survey highlights the extreme difficulty that many people have in trying to save, as 35% of respondents had never saved any money at all.
Excluding unused credit and store cards, or ones where the borrowing was repaid every month, 48% of households had some sort of outstanding unsecured borrowing.
More than half (52%) of those who used a credit or store card said that making the minimum repayments was a burden, and 15% had failed to make some of those repayments at all.
"If you include all financial commitments, 10% of all households were in arrears for at least one commitment," the ONS said.
"The median amount owed across all types of commitment was £400."
The 25-34 year age group was the one most likely to have stacked up some sort of unsecured debt, with 68% of this group in this position.
Their debts were the greatest of any age group too, at an average of £3,700 each.
The survey revealed that while 59% of people surveyed expected to receive a personal or company pension when they retired, only 40% of men and 32% of women were actively contributing to such a scheme.
The survey also found that:
• the wealthiest 50% of homes owned 91% of household wealth
• by qualifications, households headed by someone with a degree had the highest average wealth of £400,200, compared to the average wealth of £105,100 held by families headed by someone with no qualifications
• by employment, households headed by the self-employed were the wealthiest at an average of £283,200
• 62% of UK households had a savings account, but a quarter of these had £500 or less in them.
• 25% of households had negligible, zero or negative financial wealth.
An analysis of the government's national accounts, by the Halifax bank for the BBC, was published in September 2009.
This calculated that the UK's household wealth stood at £6.736tn at the end of 2007 and had dropped by £815bn, or 12%, to £5.921tn.
The Halifax suggested that this meant average household wealth fell by £31,000 last year.
The ONS figures do not capture the full effect of the recession and housing slump that took place in 2008.
But they do show that the nation's wealth was originally far higher than the estimates derived from the national accounts.
An ONS spokesman said the main reason for the difference was probably that the new survey attributed a higher value to households' accrued pension rights than the national accounts.