The white stucco townhouses of Cornwall Terrace overlooking Regent’s Park in London were designed by Decimus Burton, the 19th century English architect, garden designer and protégé of John Nash. At more than 10,000 sq ft each, these splendid examples of Regency architecture could not in any way be described as mean or cramped. Nonetheless, Westminster council is considering a planning application from a member of the Qatari royal family, who owns 1, 2 and 3 Cornwall Terrace, to combine the properties into a single home which, at 34,155 sq ft, would be more than 30 times the size of the average UK house.

If this scheme was a one-off it could be ignored as the whim of a wealthy eccentric. Yet in north London workmen are also renovating and expanding Witanhurst, a historic property in Highgate, that, when completed, will be the city’s second largest private house after Buckingham Palace at 90,000 sq ft.

Meanwhile, developer Christian Candy is extending Gordon House in Chelsea into a 25,000 sq ft property; and the Reuben Brothers are converting the Grade I-listed, former In & Out Club building in Piccadilly into a 53,426 sq ft home, to go on sale for ￡250m.