Those around in the UK in mid-August were vastly entertained by the Channel 4 TV programme so elegantly titled "the F***ing Fulfords". Billed as "Devon's answer to the Osbournes - but in tweed" this looked very like a pilot for a reality series. It was based on the bonkers, bigoted Fulfords, an aristocratic family fallen on hard times. After 800 years in the same estate, the Fulfords are now having trouble finding the £30,000 or so a year it costs merely to run their house, let alone the million it needs to stop it falling derelict. Money-making wheezes abounded, but going to the government cap in hand was not one of them. Getting the cameras in, however…

At the other end of the spectrum, you have the glory that is Chatsworth in Derbyshire, built in phases from the 17th to the 19th centuries. It looks impregnable today, but like so many country houses, by the 1950s it faced the bulldozers. It was only due to the energy and enthusiasm of the late Duke of Devonshire and especially his surviving wife, the universally loved "Debo" Devonshire - last of the Mitford sisters, who describes herself as a housewife - that Chatsworth was restored, placed in trust, and opened hugely successfully to the public. As it was, death duties meant that the young Devonshires had to lose their other great country house, the Elizabethan Hardwick Hall - now inevitably National Trust.

Today, you don't find so much of the Chatsworth brand of fighting spirit, or the related commercial enterprises such as Longleat or Woburn. Instead, you get Tyntesfield. Tyntesfield is a high-Victorian Gothic pile, built by a guano millionaire, that had languished in obscurity for 140 years. Scarcely a photo of it was to be found. It was designed by second-rank architects, John Norton and Henry Woodyer, with a chapel by Sir Arthur Blomfeld. Although it is only eight miles from Bristol, nobody got to go there unless they were friends or relations of the owners. Because it kept itself to itself, nobody missed the fact that they were sadly deprived of the opportunity to go there by the coachload. But then, in 2002, Tyntesfield came up for sale. Its last owner, Lord Wraxall, had no children and the estate passed to 19 relatives. They didn't all want to live there together, and nobody was wealthy enough to buy out the others, so it had to be sold. Whereupon, it suddenly became a spectacular treasure that just had to be saved for the nation.

Those campaigning to "save" Tyntesfield trotted out the old line that this was surely the last great country house to come up in this way. Just as they had in 1991 with the previous "last great house", the Jacobean mansion of Chastleton in Oxfordshire. That one also cost a mint to buy and preserve. Once again it was the National Trust, once again large amounts of public money poured into it. I remember it well, because at the time I found it strange to the point of absurdity. Dusting down the article I wrote in The Sunday Times back in November 1991, I find I wrote this: "Chastleton is one of those time-capsule houses that are always unique, priceless and central to Britain's cultural patrimony, until the next one comes along. We have had Canons Ashby in Northamptonshire, Calke Abbey and Kedlestone Hall in Derbyshire, Nostell Priory in Yorkshire, Ightam Mote in Kent - all now Trust properties, which needed huge sums to be given the familiar Trust brand image. Next off the production line is Chastleton."

This knee-jerk response - for the state to cough up whenever a reasonably OK country house looked like falling into the wrong hands - dates back to the 1970s. A key exhibition in 1974 at the Victoria and Albert Museum , "The Destruction of the English Country House" highlighted the losses during the 20th century, despite the National Trust's highly successful post-war rescue programme. Then the contents of the 1855 Mentmore Towers in Buckinghamshire, an 1855 pseudo-Elizabethan confection by Joseph Paxton, came up for sale. The contents consisted of Lord Rosebery's magnificent collection of furniture and art. There was an outcry: could not the state step in? It did not, the contents were sold for £6 million, and the emptied house was later sold to the Maharishi Mahesh Yogi. Today it houses his University of Natural Law and its grounds contain a golf course. As a direct consequence of the Mentmore incident, the National Heritage Memorial Fund was set up as a "fund of last resort", principally to stop works of art leaving the country or being dispersed. The cry is always: Remember Mentmore! As a consequence, no important English country house has been "lost" for 30 years.

In 1991, the £6m handed over by the National Heritage Memorial Fund to buy and help restore Chastleton (restoration costs were given as £9.5 million) was stratospheric. Incidentally the place is deemed so fragile and peaceful that only handfuls of visitors are allowed in. So I'm not sure how that stacks up on a value-for-taxpayers-money basis. But Tyntesfield makes Chastleton look cheap. This time, the NHMF shelled out £17,425,000 towards the £25m cost of saving Tyntesfield from being bought by someone unsuitable (Kylie Minogue was mentioned). And now the associated Heritage Lottery Fund (HLF) is humming and hawing over whether to grant a further £20m to the National Trust to restore it. A decision on the application has been deferred. Apparently they want to be sure there will be "maximum benefit from this investment". Perhaps they remember Chastleton. But I expect they will cough up anyway. The money has been set aside. That will make nearly £38m of public money, paid out to a previously invisible house that is likely to cost £45m in all to Trustify.

To put this in context, a trifling £15m from the HLF would have tipped the balance to allow the Victoria and Albert Museum to build its long-delayed Daniel Libeskind-designed extension: the museum had private donations dependent upon it. But the HLF turned them down, so this project to improve and expand the display galleries of one of our great national museums is now dead in the water. In case you thought the word "Heritage" ruled out new buildings, not so. Norman Foster's American Air Museum at Duxford in Cambridgeshire, and Sir Richard MacCormac's Ruskin Library at Lancaster, are both all-new buildings that have benefited from HLF funding. It is likely, however, that the V&A's determination to use the Spiral for contemporary design - including architecture - rather than its historic collections counted against it.