Some ideas are so simple, logical and right for their times that as soon as you hear them you wonder why they haven’t been tried before. Setting up a pre-school nursery in a home for the elderly, so that the very young and the very old can be cared for under the same roof, is just such an idea; one which has so caught the public imagination that Ros Ward, the Sevenoaks nursing home matron who thought it up, now has the interview schedule of a Hollywood star.

It’s easy to see why newspapers and radio stations have been beating a path to her door. The scheme brings the generations together; it helps the home to attract good staff by offering cheap, on-the-spot childcare; it brings much-needed nursery places to the community pool; and where better to look after young children than in an institution already geared to their practical needs?

“Our residents often need help with feeding and so do little children, ” says Ros Ward. “Both groups can have problems with incontinence. When it comes to food, our kitchens are used to preparing small, colourful, attractive, nutritional food to tempt small appetites. When it comes to fire safety, children take as long to get out of a building as the elderly. We have all the systems already in place.”

But the real value of the scheme, she says, is the way it enriches life in the home. “People come here and they think their lives have finished. They think it’s a death sentence, but when they come through the door here they hear children’s voices and they know that life goes on.” Seeing and hearing the children, playing with them, and acting as surrogate grandparents, has had an obvious impact on residents. They talk enthusiastically about them, and it might be more than coincidence that since the scheme was introduced there has been only one death in the home - highly unusual in a place which cares for 60 frail residents, many of them over 90.

Emily Jackson House was opened in 1994 by a private company, Westminster Health Care, to care for a mixture of private and NHS residents. Once a derelict children’s TB hospital, it is now as warm and welcoming as a hotel. Ros Ward, a former health visitor and college lecturer, was already familiar with the needs of different age groups and the empathy that can exist between young and old.

“They have a natural understanding,” she says. “The old have the time to listen to children, and the children accept wheelchairs and disability. They don’t think anything of it.”

Ros quickly realised that the top floor of the building, which had no wheelchair access and therefore could not be used for nursing the elderly, would make an ideal nursery. But it took more than a year of research, planning and fighting local bureaucracy to get the nursery open in the summer of 1996.

Convincing the area health authority was one of her hardest battles. “They said you can’t run two businesses under one roof. They said they had never heard of it. They kept saying this will set a precedent. After four months they finally said ‘Yes, you can if do it you have a separate entrance and manager’. ”

Partly because of this, the scheme does not replicate the unfettered mixing of family life. The two dozen two to five-year-olds in the nursery arrive and leave the building by a back door, go out to their garden in the same way, and spend most of their time on the nursery floor. But the residents can watch the children playing in the garden, the children go downstairs to visit them, and there is a shared weekly music and movement session. “They help show the children the movements,” says Ros Ward. “If the children are doing ‘Incy wincy spider’, they will join in. With the children there, they lose their inhibitions. You see the arthritic foot tapping, and you know it helps them to forget their aches and pains for a moment.”

But it is the casual contacts that everyone talks most about - the joint renditions of “Happy Birthday”, or young and old heads bent together over a jigsaw.

“If you’re downstairs you see them going through,” says resident Evelyn Parsons. “They’ll come and have a look at me and I wave to them. Sometimes they hold their hands out for sweets.”

“My window looks down over the garden and I can see and hear them,” says Hugh Hinton. “And they’ll come in three or four or five at a time. They bring their toys and talk about them. It brings the outside in. But they’re always heavily under supervision. If they were allowed to hurtle around inside there might be a few objections.”

Great care is taken to respect differing needs. If residents want nothing to do with the children, that is their choice. Winter coughs and colds are kept out of the building, and the children’s laundry, and their plates and cutlery, are kept separate from those of the residents.

But the advantages clearly outweigh any potential problems, and Ros Ward sees endless possibilities for expansion of contacts between old and young, with shared art and exercise sessions among her plans.

Meanwhile, Westminster Health Care is already planning six more nurseries on nursing home sites to add to the Sevenoaks scheme, and another facility is up and running in Yorkshire, where the two age groups share a site, although there is no interaction.

“It helps us to attract good staff,” says Pat Carter, chief executive of Westminster. “It also makes us a bit different, and hooks people’s interest.

“We hadn’t realised the possibilities for interaction until Ros came along. What we now need to do is to see if we’ve got something that can work as well under people who aren’t as exuberant and exceptional as she is, and whether it will still strike a chord in a few years’ time when the novelty has worn off.”