When I see the house price indexes rising I can’t stop myself. I have to do a sum that estimates how much richer we are as a nation.

Here’s how I do it. I head straight for the Blue Book (a set of the nation’s annual accounts, if you like) and flick (metaphorically, as I use the pdf version) to the balance sheet numbers. That is table 10.2 in the current edition to be precise.

It tells me that the nation’s housing stock was, in the view of the national statisticians, worth £3,922.6 billion at the end of 2008, having fallen from £4,313.6 billion at the end of 2007.  There really are some big numbers in that book, fantastic.

Then I divide this by the housing stock, which generally increases each year by a shade less than 1%. The UK stock at the end of 2007 was 26,652,000, which put the average asset value of a home at roughly £161,850.

Sadly the rather overworked folk who put together the housing stock figures are a bit later in getting the 2008 data out, so I have had to estimate. I plumped for 26,850,000. That would put the average asset value of a home at the end of 2008 at £146,000.

That's a shade under a 10% fall.

So let’s play "what happened in 2009". We'll start by putting a figure on the house price rise in 2009, say 5%, and increase the stock by 0.5%, given so few homes were built.

That means we end up with an asset value of £4,139.3 billion.

Put another way, if we're right, Britain is £216.7 billion richer than a year ago on the back of house price rises. That's about three grand for every man, woman and child in the country.

And what’s more, if the latest Halifax figures are a fair reflection of price rises, we just got £25 billion richer in January.

Now I understand why house prices rises are so appealing...or have I missed something obvious here?