A royal bungalow in the Tesco style

The Royal Family is not known for its taste in architecture. When, in 1956, James Pope-Hennessey, the impossibly grand curator and art historian, went to see Sandringham, the family's grandiose holiday cottage in north Norfolk, he found the Saxe-Coburg-Gothas' lumbering, late-Victorian pile "tremendously vulgar and emphatically, almost defiantly, hideous and gloomy". As the "Pope", a famous snob but an aesthete of impeccable taste, was writing the official biography of Queen Mary at the time, he was doubtless holding back from expressing his true opinion of Sandringham. "To sum up," he wrote judiciously, "this is a hideous house, with a horrible atmosphere in parts and in others no atmosphere at all."

Nine years earlier, Harold Nicholson had been commissioned to write the official biography of George V. He visited York Cottage, the late king's favourite home, an 1860s "cottage" in the grounds of Sandringham, complete with pseudo-Gothic and Joke Oak additions commissioned by George V himself. Nicholson, another man of learning and taste, took a good look round and, drawing on his by no means inconsiderable literary powers, described this representation of royal taste in brick and stone as a "horrid little house".

It should come as no surprise, then, to find that the Prince of Wales's latest venture into the realm of architecture, in his grounds at Highgrove, has met with less than flattering criticism. The Prince purports to stand for fine and noble principles in architectural design, and lambasts modern architects, but when he himself embraces the Mistress Art, things just don't seem to work out. The "Orchard Room", a vaguely Classical bungalow designed by Charles Morris, a Norfolk surveyor whom the Prince met at Sandringham, has been described this week as being "like a Wimpey house" in "the Tesco style". Its gabled roof is "oversized", "its squat little columns are toy-like", its chimney is "feeble". And these are not the comments of zealously Modern architects, but those of the polo-necked jumper and designer-suit tendency: among others, they are culled from The Daily Telegraph, no stranger to the royal embrace.

Are people being cruel? Surely the Prince must be allowed to build in the style he feels most comfortable with in his own backyard. The style he has chosen - a sort of, you know, vernacular Georgian thingy - is entirely in keeping with his own beliefs on architecture, and as appropriate for Highgrove as York Cottage was for Sandringham or his brother's Kentucky Fried Georgian excrescence in Windsor Park.

The Prince views the new "Orchard Room" as "a country building with elegance", which is, it must be said, the sort of line one has come to expect from house-builders who, collectively, are undermining the quality of what remains of our countryside with their "vernacular-style" Neo-Georgian and Tudorbethan homes.

The Duchy of Cornwall, the Prince's own West Country fiefdom, toes the house-builders' line. Apart from Poundbury, that Toy Town development on the fringe of Dorchester in Dorset, the Duchy is busy erecting no fewer than three hundred potty "vernacular" houses on the edge of Shepton Mallet, Somerset, and 31 new homes in the guise of "barns", "gate-houses" and "Georgian-style cottages" on the Cornish coast at Pentire.

Sir John Betjeman, whose favourite spot this was, will be turning in his grave. Making barns into houses and architects' studios is bad enough (why not convert them into barns?), but to build twee new homes in the guise of old barns that have been converted into homes borders on the perverse, if not the pathological. As architects are unnecessary to design such rural fa-las, so the Prince has done without the services of an architect at Highgrove. There is no reason why an architect has to be employed on the design of what is only a small estate office for princely business and charitable events.

In any case, the pedigree of Charles Morris is beyond reproach. He is the great-great-grandson of Sir John Kelk, who built (but did not design) the Albert Hall on Kensington Gore, and thus a Good Thing. The genes of Sir John have clearly passed through to young master Morris, as you can see from the picture above.

The important thing, here, is to keep a sense of proportion, even though the Prince and Mr Morris have failed to do just that (my dears, just look at those columns). The "Orchard Room" is just the tiniest of carbuncles and few people will ever get to see it. It is entirely fit for its purpose and reflects the taste and ambitions of those who commissioned and built it. Most of all, it follows royal precedent. Poor "Bertie" - Edward VII to you and me - was so upset, when Prince of Wales, by the handsome Georgian house (frightfully middle- class) that stood where Sandringham stands today, that he had it demolished and brought in A J Humbert as architect and Goggs Bros of Swaffham (builders) to fashion the grim Victorian pile that James Pope-Hennessey was unable to find a kind word for.

The house was made to look even more like a railway hotel than it did when first built by additions made by Colonel R W Edis, architect of the Great Eastern Railway's headquarters at Liverpool Street. Some years ago, Prince Philip wanted to demolish much of Sandringham to build anew, but was stopped in his tracks by the Queen Mother, who thought the family should respect its own history.

You can't say fairer than that. The Prince must be allowed to build "Wimpey"/"Tesco"/"Toy Town" bungalows in the grounds of his own home. It is, in any case, what many smart people in the area do when not converting barns (thus denying them to more deserving owls, bats and interesting rodents) or erecting garages (sorry, "carriage houses") in the guise of barns.

Even so, for all our sakes, for those of our children and the future of what we call "the countryside", such buildings must be held in check safely behind the high walls of Highgrove and other royal estates, or in the grounds of those who still wish to court favour with the Royal Family.