Boarding has been in decline for a decade with numbers down from 125,000 in 1985 to 90,000 last year.
Ros McCarthy, head of Cobham Hall, Kent, and chairman of the Boarding Schools Association, says the answer may lie in more flexible boarding arrangements.
Some schools, she told the association's annual conference, now give pupils the chance to book one "sleep-over" a week which may be increased to three or five "as they get older and their enthusiasm grows".
Figures to be released next week by the Independent Schools Information Service, are expected to show that "occasional boarding", measured for the first time in the schools' annual census, is on the increase.
This may be known as "flexi-boarding", "opportunity boarding" or "Friday night boarding" for those whose parents wish to have a night together without their children.
Mrs McCarthy said: "Perhaps in this day and age we should adopt more user-friendly terms and become known as sleep-over schools. Children and parents understand this concept and find it very attractive."
Weekly boarding began 10 years ago and is often used by families where both parents are working. Flexi-boarding is an extension of this.
Full boarding has become increasingly unpopular with a generation of parents which is reluctant to send its children away from home. It has also suffered from cutbacks in the armed forces which have reduced by half the number of children receiving the Government's boarding school allowance.
Boarding schools have worked hard to shed their image of hard beds and cold showers and many have invested in new accommodation.
Mrs McCarthy said: "One small boy looking at brochures of prep schools asked his parents, `Is this a hotel for children?' For senior schools with their single rooms, en suite showers, sports centres, tennis courts and swimming pools, boarding is the wrong word. These are hotel facilities worthy of stars."
But Mrs McCarthy said they were still struggling against outdated ideas about boarding. "There are as many happy, well-adjusted children at boarding schools as at day schools. Schools of any kind can be good or bad so why the witch-hunt against boarding?"
A spokesman for the Independent Schools Information Service said that prep schools had been in the forefront of flexi-boarding, perhaps because the decline in full boarding had been particularly marked among younger pupils. "It must reflect a feeling among some parents that eight is a bit young to be sending away children for long periods."
Occasional Friday night boarding, he added, was convenient for those schools which wanted to keep Saturday school going.
He said: "This isn't a last desperate attempt by boarding schools to make themselves attractive. It is the other way round. This is what parents are asking for so schools are having to adapt what they do."
Education+, The Tabloid