It's the most radical change to schools since schools were invented.
Virtually everyone working with children agrees it is the way of the future. More than pound;50 million has been ear-marked to get it off the ground. But how well will it actually work?
The idea of turning schools into one-stop community shops for children and families has been on the agenda for the past three years, and given added impetus by the moves to integrate children's services enshrined in last year's Children Act. The programme is already under way and by next year every authority will have at least one full-service extended school, with many more schools offering a more limited extended agenda.
At the same time, children's centres are to provide joined-up services for pre-schoolers, while local children's trusts are bringing together children's services. All of which puts such schools in the thick of the new integrated agenda designed to revolutionise how society deals with the needs of children and families. Some schools have already achieved big changes. They provide on-site health care to students, have police officers on the premises, run adult education, or offer creches and after-school clubs.
However, pioneering schools are often run by dynamo heads who drive things through by sheer force of will. Lesser mortals could find it harder to knit together this complicated mix of childcare, health and social care, life-long and family learning, study support, sports and arts, and access to IT. But there is no shortage of support. Conferences, networks, tool-boxes and training are on offer, along with various pots of money, and an array of blueprints. But the move makes huge demands on people. It requires professionals from health, education and social services to change their thinking. It needs a new approach to school management, an eagle-eyed approach to snaffling funds, and good, flexible local relationships to make it happen. Such schools may, as the enthusiasts say, offer the best chance to provide properly for children and families, but could also offer a golden opportunity to breed bureaucracies, multiply meetings, and accelerate the use of acronyms.
"The conclusion I've long since come to is that you have to have clarity of purpose, because while very good things can be done when schools get involved with communities, there is the danger that you end up with a lot of rather unco-ordinated activities," says Alan Dyson, professor of education at Manchester university, and leader of the national evaluation of full-service extended schools.
"The issue from the school's point of view has to be: what do they hope is in it for them? If they see this as an important part of the bigger picture of children's development, they are more likely to be able to deal with the give and take needed to set things up."
David Hawker, director for children, families and schools in Brighton and Hove and experienced at working in an integrated setting, agrees. "Children don't come in single boxes. You have to have a vision of children within families within communities," he says.
However, he believes that children's trusts, whose setting up will be made easier by the Children Act, will help schools to manage in a multi-agency context "because then you have already built-in joint arrangements".
But full-service schools throw up multiple issues over funding, inspection, governance and management. The Children Act directs local authorities to create directors of children's services, and for Ofsted to lead an integrated inspection framework, but big questions remain. How can health workers and teachers work together when they are tied to different targets? What about site security and child protection if a school is open to all-comers? Who is in charge of the extended school day? And the big questions spawn a thousand little ones: for example, is the head accountable for a health worker who is handing out condoms in school, or for poorly run adult learning classes?
"These are very real and immediate issues," says Maggie Farrar, an assistant director at the National College for School Leadership, which is supporting networks and developing leadership training for community and multi-agency working.
"Heads know that if anything goes wrong in school, parents come straight to their door. But there has to be a mind-set shift for headteachers. They have to know that they cannot and must not do the work alone."
Early experiences show that the more that power is shared, the more thinking and resources are brought into the school from other quarters.
Many schools have also found that having a designated manager for extended provision works better than loading extra duties onto existing senior staff - a potential recipe for disaster. Workforce remodelling also offers opportunities for creating new working patterns for schools.
However, Stephen Pisano, a former headteacher now working for the charity Coram Family, points out that collaborative ways of working have already been extensively pioneered in education action zones. "So while some areas will feel they have a mountain to climb, others have already had partnerships working for several years," he says. "And a lot of heads are now sensitive and sympathetic to the idea of not working on their own.
There's a real swelling of commitment and interest. You can't get into conferences on this topic now. They're packed out."
The key thing, he says, is that no one model works in all locations. "This is something that works from the bottom up. It's all about relationships and partnerships."
Alan Dyson makes the same point: "It's very important whose views of needs prevails. If you talk to the professionals, they will all rattle off a long list of problems, low aspirations, low attainments, and so on, but then if you talk to people in the area they will have a long list of problems with services. You have to ask, 'How real is the involvement of local people?'"
There is a clear need for a strategic framework. The original idea for stand-alone full-service schools quickly gave way to more flexible models, and there is a growing awareness that local authorities must bring coherence to integrated services.
Then there are all the special interest groups to accommodate. Alan Tuckett, director of Niace, the adult education body, points out that while extended schools are great for basic adult learning, it is crucial that these learners are helped to move on to the next step: to college or another course. "We must make sure the linkages are there," he says. "We simply can't afford to have blind alleys."
Will all this effort be worth it? Maggie Farrar is absolutely clear. "We know from Ofsted that schools that have strong relationships with families get a better than average rise in attainment. Focusing exclusively on the classroom just doesn't work. By extending schools you are investing in the skills of the parents."
And Alan Dyson cautiously concludes that "in terms of short-term outcomes, for particular children, the evidence is that it is a jolly good idea and the direction we should be going in."
Whether this will hold out for all children, and over the longer term, is as yet unproven. Early indicators seem promising, although he warns that it would be foolish to think that just by throwing the doors of our schools open more widely than before we will have found a magic solution for poverty and disadvantage.