IN 2009 America sold its embassy in fashionable Grosvenor Square for a reported £500m ($800m) to Qatar’s sovereign wealth fund. By 2017 its new embassy should be ready in gritty Vauxhall. The details of embassies’ ownership or leaseholds are not known, but a new survey has created a sort of “fantasy embassy valuation”, estimating how other nations could be cashing in.

The report, by Spear’s, a magazine, and Lichfields, a buying agent, suggests that the embassies of Japan, Germany and Saudi Arabia could be worth more than £100m each (assuming they were sold as residential freeholds). More surprisingly, the Nepalese embassy and Zambian high commission, both in Kensington, are worth £30m and £40m respectively. Many members of the British Commonwealth gained locations in central London decades ago: Uganda, Zimbabwe and Tanzania have swanky central digs that would fetch a fortune.

Some are already liquidating their assets. Canada sold the long lease on Macdonald House, its consular section in Grosvenor Square, for £306m last year. The Dutch embassy on Hyde Park Gate is for sale and could fetch £150m. The Chinese may sell their embassy in Portland Place and search for a new site, perhaps also in Vauxhall.

The cheapest embassy appears to be North Korea’s semi-detached house in Gunnersbury. But least proportionate to national wealth could be the consulate of Tuvalu, based in a £750,000 property in Wimbledon. If sold, it could pay off 11% of the tiny state’s national debt.