As the door swings open to reveal the large cupboard that is now a shop, the scale of the school enterprise becomes clear. Rows of small blue fleeces hang from rails, jostling for space with chests of drawers, packed with folded white shirts, grey trousers and blue tops, each carrying the white dove of the school badge, surrounded by "Our Lady of Peace Primary School".
School uniforms are a big expense for parents, says Mari Kennedy, acting principal teacher and enterprise co-ordinator - especially those with very young children, who seem to put on inches every time you turn your back on them. "So our enterprise committee came up with the idea of recycling school uniforms. Then they created a business plan and presented it to the Dragons' Den."
A competitive forum for schools to pitch social enterprise ideas and receive funding to get them off the ground, the Dragons' Den run by Renfrewshire was nearly as tough as the TV version, say the pupils who took part.
"I was a nervous wreck," says Kieran Robertson (P7). "I get picked a lot by teachers to do talks, so I'm usually OK getting up in front of people. But not this time."
The waiting wasn't easy, says Emily Dick (P6). "You did the presentation with everybody looking at you. Then the judges were deciding. That was hard. You were nervous and excited and didn't know how to feel."
But it was worth the wait, says Ms Kennedy. "We won best primary school and best school overall, and they gave us #163;800 to set up our enterprise."
"We only asked for seven hundred," adds Gerry Barr (P6). "But we were so good they gave us eight. One of the other teams bribed the judges with biscuits. But we still won."
So what were the origins of the social enterprise idea that so impressed the Dragons, and how did the team develop it?
"Wilma Leburn told us we had to think outside the box and come up with a social enterprise (see panel)," says Ms Kennedy. "Something to benefit the school and the community."
The school's environmental committee suggested all kinds of ideas initially, she says. "They thought about sending books to Africa. Then they wanted to Astroturf the pitch and charge admission. But that would have cost #163;10,000.
"Then a man called David Black from Gilmour Sports, who's very kind to our school, donated a box of fleeces, and we discussed what to do with them. We realised that once they were sold they were gone. But we wanted something sustainable. That's when the idea of recycling school uniforms was suggested."
One of those great ideas that seems obvious once someone has thought of it, this enterprise needed lots of equipment to get it off the ground. Drawers, rails, clothes-hangers, iron and ironing-board, metal bins, washing machine and tumbler-dryer were all included in the business plan - although the last two were eventually donated, leaving the budding business with spare funds they used to buy curtains for the school's new nurture room.
"One of the children said charity begins at home and they all thought it was a nice idea," says Ms Kennedy.
A major shopping expedition in a borrowed mini-van saw pupils and teacher return with everything they needed, explains Jamie Rankine (P6). "We bought so much, we weren't sure it would all fit. Then we put the white bins at every entrance. Once people started leaving uniforms, we sorted them into piles of different sizes in the classroom."
Word of mouth, text messages, and school and church newsletters helped get the story out to parents, says Ms Kennedy. "Our computer system lets us send the same text to everyone and lots of uniforms were left.
"We now have a big wash planned this week, which the children are looking forward to, with volunteer adults doing all the ironing. Our Ecoforms Shop - from 'eco-friendly' and 'uniforms' - will officially open at the end of November."
So what exactly is the point of this ambitious enterprise - are the children aiming to make lots of money for themselves?
"No!" they reply loudly, immediately and in chorus.
"We are trying to help," says Kieran. "People don't like buying new uniforms all the time. Some can't afford it."
"If we help people, they will help the school," says Emily. "Then we will all be happy."
The finals of Renfrewshire's Dragons' Den are held in Reid Kerr College. "They provide the venue free, allowing us to keep more funding for schools to bid for. Their new principal will be one of the Dragons next year," says enterprise development officer Wilma Leburn.
The aim is to link financial education with social enterprise, stimulating pupils to create ideas, develop business plans, apply for funding, then run real businesses, she says. "The Dragons evaluate the proposals and decide what level of funding is appropriate for each finalist. Enterprises have to be sustainable and comply with practices adopted by businesses in the real world - as in the exemplars from the Social Enterprise Academy."
A conventional classroom approach would not have had the same impact, she says. "We're giving young people a role and encouraging them to be responsible for their own business. Schools have really engaged with the idea, and their businesses are now going concerns. This project is education in its original sense. It leads out of children their natural interest and desire to learn."
The next round of Renfrewshire's Dragons' Den begins in January 2011, with the finals at Reid Kerr College on June 1.
Social Enterprise Academy www.theacademy-ssea.org.