"That would be true inclusion," she says. "You would be serving the needs of the community in one area, instead of special needs children being taken from one authority and delivered into a special school miles away."
Some authorities have made mistakes, she says, in closing special schools.
But she believes lessons have been learnt and special schools are here to stay.
"We could have more children with special needs in the mainstream, but we need to be more adventurous in the way we do it," Colquhoun says. "We could, for instance, have more dual registration - closer links between maintained and special schools so that children can work at two sites."
Born and bred in Newcastle, Elaine Colquhoun has been head of Hill Top school since 2000. She began her working life as a nurse and then a primary school teacher, but after three years in the maintained sector she moved into special schools and has never looked back.
"It's continually challenging and uplifting," she says. "I've never stopped being challenged because we have diversified so much over the years."
Inclusion of special needs children in mainstream schools has widened Hill Top's intake to include children with severe, as well as moderate, learning difficulties, and children with severe autism. The school has worked hard to cement links with local mainstream schools, and Colquhoun is particularly proud of the accredited snorkelling and diving course it runs for its own pupils together with those from a local secondary.
Golf is another activity that the two schools have collaborated on, and mainstream sixth-formers come to do shared reading with Year 7 Hill Top pupils every week.
LEAGUE TABLE PROBLEMS
One of the biggest barriers to inclusion, she believes, is league tables and the pressure for good GCSE results. "We get a lot of children referred to us in Year 9 because mainstream schools don't want them in Year 10.
That's league-table driven."
Mainstream schools, she argues, should put more energy into providing alternative qualifications - units of accreditation or certificates of achievement - for special needs pupils who are not capable of gaining GCSEs.
Colquhoun's vision for Nasen is that it should have a broader outlook. "We need more international links so we can learn from others how they deliver," she says. "We need to have more sharing of practice."
Colquhoun's work in China is a case in point. In 2002, she visited China as one of a British Council delegation of heads, and Hill Top is now twinned with Luwan school, a special school in Shanghai.
Luwan school has learnt from Hill Top the value of sensory education - it has developed a sensory room, having had no concept of this before, says Colquhoun - and realised that children with profound and multiple learning difficulties need not be left to languish at home. Hill Top has picked up calming eye exercises and a special Chinese dance for use in regular "active breaks".
At Nasen, Colquhoun wants to see more liaising with charities working in similar fields, more feedback from ground-level, more input from parents and more practical, hands-on projects, such as the recent school poetry competition.
At the strategic level, the appointment of five trustees from outside education has been "a breath of fresh air", she says, and Nasen is working increasingly with health and social services, as well as education.
"We're moving toward a much more focused, business-type approach - as well as a more inclusive one," she says.