Ten years in construction and 20 on a skateboard, Matt Elms is perfectly qualified to turn a patch of north London into heaven with a half-pipe.

鈥楲ook at the finish on that!鈥 exclaims Matt Elms, crouching to run his finger along a paper-smooth block of solid concrete with a gleaming stainless-steel edge.

This is what skateboarders like Elms call a grindbox 鈥 in street-skating they slide their boards along it at high speed.

Elms is giving me a tour of the new Cantelowes skatepark in north London, which he鈥檚 been project managing. Now 34, he鈥檚 been skating since he was 14. By day, Elms is a for Mace, but for the past five years, he and three skater friends have been devoting their spare time and professional skills to project managing the refurbishment of one of their old haunts.

When we catch up with him, the relaunch party is just a-week-and-a-half away, the banks and bowls where skaters will hone their tricks are in place and the hand-finishing of the concrete on the 1,000m2 site is almost complete.

鈥淭here鈥檚 a lot of excitement about this in the skateboarding world,鈥 says Elms. 鈥淎ll of us 鈥 the skaters, the council, the contractors 鈥 wanted to build the best skatepark in England. We volunteered because we knew we had the skills and we wanted a really good skatepark to replace the old one,鈥 says Elms.

鈥淲ithin the group that skated there, there were people who had experience of design, building and engineering that we could use. We didn鈥檛 want Camden to employ someone to tell us what to do. I鈥檇 never built or designed a skatepark before but I鈥檇 been skating for 20 years and building for 10.鈥

His opportunity came when Camden council began a 拢1.5m redevelopment of the shabby Cantelowes Gardens, which includes the 20-year-old skatepark. Although it had a basic design and the concrete was starting to crack, it was a favourite among skaters from across the city. Elms is from Barnet, to the north, but recalls making many trips to Camden. The council asked Elms鈥 friend, Perry Wilson 鈥 a local BMXer 鈥 if he knew anyone familiar with skatepark construction.

Elms jumped at the chance. He roped in two friends he鈥檇 met through skating 鈥 Jeremy Donaldson, an architect at Robert Dye Associates, and Hareth Pochee, an working for Max Fordham 鈥 and they formed the Cantelocals design team.

鈥淣ext thing, I was in a room with four people from Camden council I鈥檇 just met and four people from Sport England wanting to know what we wanted,鈥 he says.

Through Mace, the council employed Elms to project manage the submission of a bid to Sport England for 拢70,000. 鈥淭hat was really hard,鈥 he says. 鈥淚t was the first time I鈥檝e ever done anything like it. The application is geared towards sports centres, and not just for capital projects but also for timetabled teaching. But with skateboarding nobody really teaches you; you teach yourself. It appeals to people without the team-game spirit, who don鈥檛 like being competitive or the hassle of being at a certain place at a certain time to be taught something.鈥

Nevertheless, the money came through and the Cantelocals set about developing designs with landscape architect Watkins:Daly. The team wanted the park to allow as many people as possible to skate together, to accommodate skaters of all abilities, and to offer a variety of terrain. They opted for equal amounts of banks, bowls and streetscape of varying gradient and height.

They were determined to avoid errors made in other parks. 鈥淪o many councils build them with tarmac floors rougher than the road and then fibreglass banks that make a humming noise when you鈥檙e on them and a metal lip in between that jolts you,鈥 says Elms.

Today, Donaldson has taken a late lunch to help hand-finish the last bits of concrete around the edge of the bowl. The Cantelocals have not only pored over how every inch of space is used but they鈥檙e also there most days to help with the building work.

He says that to design the park, they had to think about the different routes people would take as they skated. 鈥淚 wanted to have separate bowls, but that added about 40% to the cost and you ended up with very little useable space,鈥 he says.

Donaldson says the project has involved very different tolerances from most construction projects. 鈥淚f the coping sticks out by a few millimetres, that inconsistency can limit the utility of the obstacle,鈥 he says. 鈥淏ut if the ramp itself is a foot longer it doesn鈥檛 make that much difference.鈥

Finding someone to build the park was also a challenge. Elms says: 鈥淭here aren鈥檛 many skatepark contractors in England and there aren鈥檛 many designers or other professional staff with experience in this kind of work.鈥

The team looked at using US contractors but none could meet the local authority鈥檚 risk requirements at the right price. In the end, they settled on Wheelscape, a Bristol-based skatepark specialist owned by Nick Fyfe.

鈥淲hen I met Nick, I couldn鈥檛 work him out,鈥 says Elms. 鈥淗e鈥檚 passionate about skateparks but isn鈥檛 a skater. Then I found out: his passion is concrete, so skateparks are a unique challenge.鈥

Elms is full of praise for the way the council has handled the project. 鈥淭hey鈥檝e been transparent all the way through, and let us get close to the people building it,鈥 he says.

Having said that, he has found the pace agonisingly slow at times: 鈥淟egal and technical barriers are most frustrating. But it鈥檒l be worth it when it opens.鈥

He admits it鈥檚 been hard to maintain the support of the park鈥檚 users during the project, but now it鈥檚 nearly finished there鈥檚 a great sense of expectation. One of the most eagerly anticipated elements is the over-vert cradle 鈥 a round lip on the edge of one of the bowls that allows skaters and BMXers to go upside-down 鈥 the first of its kind in the UK.

The project has left Elms keen to work on more skateparks. 鈥淧eople think it鈥檚 a fad but there are more and more skateparks around the country and they鈥檙e always going to be used by BMXers or rollerbladers or whatever.

鈥淚鈥檝e been skateboarding for 20 years and my wife skates, and when we have a kid, he or she will do it too. I鈥檓 never going to stop.鈥