Sydney One of Australia's most cherished institutions is under threat. We're not talking about long weekends, the morning 'smoko' tea break or live cricket on the radio, but the much-maligned student share house. Long regarded as a rite of passage between school and adulthood, the share house has provided generations of young Australians with their first taste of independence, romance and all-night partying while, hopefully, picking up some domestic skills. Now it seems the shabby terrace with its futon mattresses, Che Guevara posters and empty fridge is about to disappear into the mists of time. Experts blame this sorry turn of events on the rise of Kippers (Kids In Parents Pockets' Eroding Retirement Savings), a new generation of adult children who refuse to leave home until they turn 30 or get married. According to the latest census, there are now 200,000 Australians aged between 25 and 29 still living in the parental home - a rise of 30 per cent over the last two decades. And Sydney, it seems, is a magnet for Kippers; the affluent suburb of St Ives has the nation's highest concentration of Kippers, with 66 per cent in that age bracket still living at home. The social trend is now the subject of a six-part documentary series on Australian television. The Nest, to be broadcast later this month, follows the lives of three families whose adult children have chosen to remain at home into their late 20s. Three hundred families applied to appear on the show. Paul Rudd, series producer at SBS-TV, said the documentary's aim was to explore the long-term effect of this on society. One family who appear in the show, the Wilkinsons, share their home with four adult children, plus their son Aaron's live-in girlfriend. 'We're not trying to be judgmental,' he says. 'We're just asking, 'What is the long-term impact of this trend? Does is it mean there will be a generation of people who do not pick up the life skills you learn when you leave home?' Bernard Salt, the Sydney demographer who coined the term Kippers, says that unlike their baby boomer parents, today's Generation Y-ers feel no imperative to leave the comforts of home. 'Housing affordability is put down as one reason, as well as [the cost of] further education,' he says. 'But I think young people just get used to the lifestyle. The kids get addicted to a certain standard of living.' He believes that the erosion of the generation gap has something to do with the phenomenon - today's youngsters are more at ease with their parents than previous generations - but says pragmatism is the main factor. Student Elise Wilkinson, 20, says that the idea of living on a tight budget didn't appeal. She also worries it might affect her university grades: 'With rents so high, this is what I have to do.' Elise and her siblings pay between A$70 and A$130 each week for full board - an average inner-Sydney rent is now around A$400 a week. Nonetheless, all of the families who appear in the SBS-TV series say that their experience is mostly positive. 'We see them as friends,' says Paul Wilkinson, the father of Scott, 27, Aaron, 25, Tara, 23 and Elise. 'There's really no downside to it for us. But we're not holding them to ransom, they can shoot through whenever they like.'