As I wait for Rona Logan, headteacher of Redburn School in Cumbernauld, Steven approaches. I can't quite pick up what he is saying but his sweeping gesture is unmistakably an invitation to make myself at home.
The children who come to Redburn are aged between two and 19 and have a range of complex and profound learning and medical difficulties. Steven is one of the older pupils; he is autistic and has problems with gross motor skills, Ms Logan explains. He finds the confines of a classroom and the presence of large groups difficult to cope with, so now he is taught "within the school premises". This in effect means that he is free to move around the school, followed by a dedicated member of staff.
"He has a trolley with his own learning tools on it and whenever and wherever there is an opportunity, he is learning. It's education on the hoof," says Ms Logan.
This tailor-made solution to a highly individual problem is typical of the education and attention at Redburn, where 16 teachers, seven instructors, 22 auxiliaries, four speech therapists and four physiotherapists care for 73 pupils.
In Steven's case, meeting and helping visitors improves his self-esteem, which in turn helps him cope with his occasional falls. The violent reactions which once characterised his behaviour have become a thing of the past.
When delivering a message to a classroom, he is learning the etiquette of knocking on the door and waiting to be invited in, developing his self-control and improving his communication skills.
Simply living within the constraints of society is a challenge for some of the Redburn pupils. Yet the atmosphere of the school is relaxed and happy.
One boy is being coaxed into his physiotherapy session. "We'll have a cuddle, will we?" teases the therapist. "I'll rub your hands and Jennifer will rub your feet."
Many people would pay good money for an offer like that.
Early assessment of children's needs makes a great difference to them and their families. Since January, Redburn has offered one session a week to families with a child under two who has been diagnosed with difficulties.
"Families weren't being identified early enough and parents were going through very traumatic times," says Ms Logan. "There is a lot for parents to learn in that birth to two-year-old period: how to deal with, play with and be at ease with their child."
In the nursery room, the pre-twos session, named Stepping Stones, is in full swing. Three babies, their mothers and a bevy of staff are going through action songs, introducing ideas such as "up" and "down", "pushing" and "slapping". When Kirsty-Anne claps her chubby hands at the right moment, her mother's face is a picture of pride and pleasure.
As well as music, movement sessions and access to facilities such as the splash pool, light room and garden, Stepping Stones gives families an opportunity to meet each other and learn what the future may hold for their child. Nursery teacher Patricia Mooney feels this gentle introduction can make a big difference .
"It can be heartbreaking watching parents. They know their child has special needs but they don't want to admit it. This makes it less daunting for them."
For specialist staff, too, it is an advantage to work with a child together, rather than individually at the family home.
"I've noticed the parents talk to us more here and to each other," says Jennifer Mearns, the school's senior physiotherapist. "Parents can feel very isolated when their child is diagnosed with complex needs and this makes them realise they are not on their own."
Driving along the road past Redburn School you could almost miss it behind its screen of trees and shrubs, but forging links with the local community and other schools is an important part of the school ethos. Cumbernauld High is just down the road and pupils visit regularly, learning about the needs of people with disabilities and how they can be met. A class from Kildrum Primary in Cumbernauld comes every week, and pupils from Redburn have mainstream placements in local nurseries, schools and colleges.
These young people may be in special education, but isolation is not part of the curriculum. They are playing their part in a process which educates us about different sorts of people, their needs and what they have to offer.
Cumbernauld is windy. At Redburn School, the newly opened sensory garden has been designed to filter the wind and offer some protection from poor weather, but today the scents of lavender and rosemary are being whipped away before they can reach your nose. In the weather corner, the bendy wind pipe that puffs a breeze into the children's faces is quite redundant.
Yet, even in the teeth of a rain-bearing gale, this is a very special place, filled with colour, movement and sound. Chimes tinkle, bamboo rustles, water spurts or flows in spirals and any sunlight shines through coloured glass.
"Our curriculum is 5-14, Higher Still and birth to three," says headteacher Rona Logan, "but it is very much based on the senses. That is how many of our children access the curriculum."
Redburn staff felt that a well-designed, interactive outdoor area would add to pupils' learning experience, but it wouldn't come cheaply. The parents set up a charitable trust to take advantage of funding opportunities.
"Our first fundraising event was a car-boot sale in September 2000 when we raised nearly pound;2,000," says Ms Logan. Over the next six months, the trust raised pound;46,000, almost half from Children in Need, pound;7,000 from Lloyds TSB, pound;5,000 from local environmental trust North Lanarkshire Forward and the community.
The garden was built by SpaceKraft, a Midlands company specialising in educational and play equipment, and officially opened last month.
"The parents have really taken fundraising on board because of it," says Ms Logan. "They've seen what can be achieved.
"One mother said she couldn't wish for a better environment for her autistic son. It encourages him to explore, discover and learn."
Learning opportunities abound in the garden. "There is colour, number, cause and effect, texture, sorting and matching I" Ms Logan rolls off the checklist.
One wall is covered in buttons, tubes and levers, like a giant version of activity centres for babies. There are relief pictures for rubbings and matching, a sandpit, distorting mirrors and croaking frogs. Children who have difficulty making sounds are encouraged to do so by the voice-activated lights. Those with ritualistic behaviours can indulge them in an environment which encourages them to notice different textures.
Benjamin is seven and has visual impairment. "He wasn't exploring his environment," says Liz Marshall, class instructor of group two for Primary 1 to Primary 3 children, "but since he's been able to use the garden, he's moving better on his own."
One autistic boy spends all his time in the garden running around the plants and bushes across the bark chippings. "He never tramples on a single plant," says Sheila Kerr, a class teacher.
The herbs dotted around the garden are used in cooking by the older pupils. "Self-help skills are a large part of what we do here," says Ms Logan. "So they can invite friends round and make them a meal or a cup of coffee."
Every Redburn school leaver has an individual lifestyle plan and learning to make choices about how they spend their time is a key part of their education.
In the quiet corner tucked behind the summer house are some trees waiting to be planted just outside the garden in memory of the four pupils who died in the past year. Three of the children were under five; one was seven.
"Bereavement counselling is a big issue for us," says Ms Logan. "It can be very difficult for the staff but we've had extra support from Rachel House, the Scottish children's hospice, and our staff are supportive of their colleagues. It's all about team support."