As we rage about the cost to the taxpayer of 80p bath plugs and the construction of elaborate duck houses, here’s a figure to contemplate.

For every new home built in recessionary times, each taxpayer is about 10p to 15p better off.

Not a lot maybe, but see 20 homes being built that might not have been and you can buy yourself a pint, if you’re not too picky.

Build 100,000 extra new homes and you’re 100 to 150 quid better off.” I’ll drink to that,” I hear you say.

Obviously if you work in house building you’ll probably be so much better off and cracking open the Dom Pérignon every Friday to toast your good fortune.
The crux of the matter is that the Treasury appears to be roughly £30,000 better off on average from saved benefits and increased taxes from the construction of every new home.

That ignores all the benefits from the supply side. It ignores VAT from the furniture that would go into the home. It ignores that extra corporation tax from builders constructing the homes and a raft of other savings or revenues.

At least that is what my calculations show me, which I post here for scrutiny Treasury gain from housebuilding.xls

I re-did these calculations after being invited to do a small presentation on Wednesday on an idea I put forward in Roof magazine in February, which in turn followed from a blog I posted here in November.

I was trying to get a handle on the tax and expenditure effects of not employing workers to build homes.

This time around I took, mainly for simplicity because I prefer simple multiplication to more complex things, the estimate produced by Professor Michael Ball in 2005 of 1.5 people years for each home.

The figures are crude, but the scale is the important bit. What this tells us is that the Treasury has lost at least £1 billion on the balance of labour taxes and unemployment benefits over the past financial year on the basis of the figures suggesting a drop of more than 30,000 homes built in the year to March 2009.

That doesn’t include the cost to the taxpayer of the massive write downs made by house builders. It doesn’t also include the loss of stamp duty and the list goes on.

So here’s a thing.

In policy terms and in theory the Government could gift 10 grand to help make up the deposit of anyone genuinely struggling to buy a new home and still come out 20 grand ahead.

A monstrously silly idea, but it does rather illustrate how much it is costing the taxpayer not to see homes built in a recession.

So the next time you see construction work on a site of 20 or so homes, raise a glass, because that work has helped keep the money to pay for the drink in your pocket.

And, what’s more, you can feel morally charged by the fact that it is keeping 30 people off the dole and producing new homes for those eager to have a better roof over their head.