In the low-ceilinged, strip-lit space, coloured lights, red and blue, flash past at speeds of up to 80km/h.

The machines bank around the cement pillars, ducking and swooping, their engine revs maxing out as they hit a straight stretch and top speed.

A collection of more than a dozen enthusiasts, all men, from their early 20s to mid-50s, are sitting on fold-up chairs or tinkering with battery packs and GoPro cameras.

The racers, their faces partly obscured by virtual-reality goggles, stand in their midst, oblivious to everything going on around them, their focus on the first-person view in their headsets.

This is drone racing — an underground circuit mixing video gamers and model makers who meet in carparks, warehouses and abandoned buildings around Sydney.

They tee up meetings on social media and arrive at predesignated locations for sessions that last about five hours, with four racers competing against one another at a time.

“Underground racing is huge in Sydney and we’ve seen a lot more doing it in Melbourne,” says Jason Warring, a 41-year-old industrial designer from the Sutherland Shire.

His backpack is covered in small drones with five-inch propellers and silicon bumpers so they can safely skid across the concrete floor when they land or crash.

He builds them himself, spending between $400 and $700 on each, but you can build a good racing drone for as little as $200. A motor costs $20, a frame $30, camera $20-$60, and flight controller $60.

Live video from the drone feeds back to the goggles via an aerial, then to a transmitter before reaching the racer, for whom the action is like being in a video game.

“When you’re learning to fly in here it can be costly,” Warring says, indicating the overhead sprinklers and pylons. “Concrete’s not forgiving.

“It reminds me of skateboarding back in the ’80s and ’90s. But now I’m kinda old so I’m not jumping fences and that sort of thing now.

“Sometimes the police drive by but they usually leave us alone. We self-police and don’t bother anyone, so we’re not often moved on.”

Before a race the droners do a walkaround, pointing out any obstacles and laying down cones to mark the course.

“Once I saw one clip a sprinkler and set it off, but usually there’s not much to damage in places like this,” Warring says.

Phil Lea, 46, a production manager from Oatlands in Western Sydney, grew up building model aeroplanes and now constructs drones with his dad on the kitchen table. He also builds LED poles to make the gates that racers fly through.

“This is a bit of relief,” he says. “You get out of the hustle and bustle of life. It doesn’t affect anybody.

“It takes a while to get used to. The only thing letting us down is the batteries. The top guys last two to three minutes. I last four, five, six minutes but I’m not as hard on the throttle.”

Sam, a 28-year-old engineer with a medical devices firm, says: “These drones are built for speed so they’re more manoeuvrable and the classes are based on prop size.

“All the racing is happening on a five-inch class. The ones you see in the parks are a little larger, like the Phantom, which is seven inch.

“So they’re spinning slower, a slower motor, a larger prop. They’re getting like 15-20, maybe 30 minutes of airtime. We’re getting about two, three minutes tops.”

“We kinda soft police — we basically have plenty of rules around where we’re flying, where we land, where we take off from. We only put three to four in the air at a time.

“So some of the guys are spotting — watching what’s going on — and the other guys are racing.

“We do take a lot of care not to damage any property, and always spotting — letting people know if cars are coming or people walking by.”

NSW police are occasionally called out to public nuisance disturbances involving remote piloted aircraft but the responsibility for policing them remains with the Civil Aviation Safety Authority (CASA).

CASA authorises a number of associations, including the Model Aeronautical Association of Australia (MAAA) and the Australian Miniature Aerosports Society (AMAS), which organise official drone racing events.

Legislation requires drone operators to keep their machines within sight unless they have permission.

“This means being able to orientate, navigate and see the aircraft with your own eyes at all times, rather than through a device such as FPV (first-person view) goggles or on a video screen,” a CASA spokeswoman says.

The tight requirements are one reason unlicensed events have taken off.

Dave Purebred, the founder of FPVR drone racing, has hundreds of registered members who compete in official events around Australia for purses of up to $20,000. (The world’s richest drone race, Dubai’s World Drone Prix, offers a $250,000 first prize.)

Purebred says a lack of spaces in NSW is another reason for some drone racers bypassing official events to seek out what he calls “bando runs”, where abandoned buildings are used.

“All the states work together,” he says. “It’s just the accessibility to field and clubhouses that other states have. Brisbane has six temporary drone-safe flying fields to try it out. Victoria is also very open to the whole idea. They see the value of giving clubs allotments of land to do it safely.

“In Sydney, a combination of a few things, including archaic policy, has slowed it up from becoming a bigger sport. We can’t actually take off from council land here. But we can fly over it. It doesn’t make a lot of sense.”

NSW has four registered drone racing clubs, with events up and down the coast, in three classes (rookie, pilot and pro) held in open fields where drones fly through various hoops and around obstacles.

“In Sydney, we’ve got one of the largest clubs,” Purebred says. “There are hundreds of racers around NSW, as well as many more who don’t consider themselves up to spec yet.”

Kevin Dodd, the secretary of the MAAA, which has 10,000 members, says his association is working with CASA on education and safety. Dodd says many drone users don’t fully understand their liability for damage or infringing people’s privacy.

“Drone racing is growing at a massive speed,” he says. “It is a game changer, like digital cameras were when first introduced.

“It would be wonderful if more councils supported the sport or, over time, as drone racing becomes more established, we expect more and more councils will embrace it.

“It is a very popular sport with our youngsters. So from a community point of view, we expect councils will progressively embrace drones.”

Of the 18 racers assembled in the carpark, many are engineers and designers.

Jack Su, a 33-year-old IT expert, says: “The tech that’s behind it has opened it up. You’re a pilot inside the drone.

“I race at least once a week. You can build a drone for $200. But once you start getting serious you want to have a whole fleet of them.

“They all handle differently based on the frame geometry, just like in a race car where you have different weights and different body shapes that affect its aerodynamics and its performance parameters.

“A micro-drone weighs the same as a cheeseburger. We pick the right drone for the right track. It’s about more than just flying.”