Then Sir Anthony Hopkins, the Oscar-winning actor, spoke up. The trust's officials were fools, he said, to reject the chance to have Dyrham Park, near Bath, featured in the award-winning film, The Remains of the Day.
The National Trust changed its policy. Now, it sees the film and television industry as one of the major contributors to the costs of maintaining and conserving its historic houses - not just in the fees paid for filming on the properties, but also in the public interest created by their appearance in major productions. It has, in the modern argot, seized a marketing opportunity and, since last year, has had a "broadcast media liaision officer" to make things easier for producers.
The result is that Saltram House in Devon may have to introduce "timed" tickets to cope with the flood of sightseers expected after Emma Thompson's film, Sense and Sensibility, is released next month. And Lyme Park in Cheshire became the destination for thousands of women who swooned over Colin Firth emerging dripping from a lake in the BBC's Pride and Prejudice last year.
Based on the Historic Houses Association recommendations, the trust suggests about pounds 2,000 for a day's feature-film work inside a property and pounds 1,600 to pounds 1,700 for the exterior, with adjustments for longer stays: Montacute House in Somerset, for example, which has an pounds 87,700 operating deficit, was paid about pounds 15,000 for 10 days' Sense and Sensibility filming.
"It's a very good boost for the house-keeping budgets and it opens people's eyes to the beauty of the properties and the sense of history," said Warren Davis, head of communications. "Allowing the houses to be used for filming has made them accessible to a much wider audience."
He has just returned from the US, where the Jane Austen revival has prompted interest in the locations. "They're all talking about the English houses they must visit," he said.
It was Mr Davis who revealed last week how Sir Anthony, four years ago, prompted thechange of policy. The trust had nervously agreed that the producers of The Remains of the Day could film the exterior of Dyrham Park, but not inside.
"Sir Anthony said in very round terms that we were going to lose out and that it was important that the houses should be used," Mr Davis said. "I felt so guilty that Remains of the Day didn't take place in our property that we thought much more deeply. The BBC's Pride and Prejudice was the turning point."
Lanhydrock House in Cornwall is due to be the next stately star. David Parfitt, producer of a new film of Shakespeare's Twelfth Night, set in the 1890s and starring Helena Bonham Carter, Richard E Grant, Nigel Hawthorne and Ben Kingsley, said the trust could not have been more helpful when it was being filmed before Christmas.
The careful preservation of Lanhydrock and nearby Prideaux Place was the clinching factor in choosing them. "In Ireland, where we looked because of the tax breaks, there were beautiful houses but most are privately owned and lots of the period details are incorrect," Mr Parfitt said."We found one castle which was double-glazed and you do notice it.
"We want people to think, 'That's a beautiful location', not 'Did they really have 13-amp sockets?' With National Trust properties, all are beautifully kept and correct in all the details and we could just move in and shoot."
Andrew Hill, assistant location manager on Sense and Sensibility, which this month won Emma Thompson two Golden Globe awards in the US, echoed Mr Parfitt's praise of the new-style trust. "National Trust houses have an absolute integrity," he said. "Saltram House, which was used for Norland Park, was the right period and absolutely the right size.
"The difference between television and the big screen is that there is no room for compromise on such detail because it can all be seen on the big screen.
"Initially, where filming hasn't been done before, there was a slight anxiety, not from the National Trust in the large sense, but from the stewards who were running the houses. But after a very short while they were very much part of the team."
Those running the houses had devised a code of practice which had helped cut the fears and the risks, he added.
Richard Hamilton-Jones, of the BBC's location unit, said that having a film crew around was "not for people of a nervous disposition".
Partly for that reason, Sam Breckman, the BBC's location manager, had always avoided National Trust properties until he "discovered" Lyme Park for Pride and Prejudice. "The National Trust does have a problem in balancing the aims of the trust and the demands of film-makers," he said.