It is dangerous. It is illegal. And his parents do not approve.
But Titouan Leduc is not planning to give up his passion any time soon.
Leduc, a 23-year-old urban climber from northeastern France, likes to scale skyscrapers without any ropes or specialist equipment, wearing only a pair of climbing boots.
"It's a unique sensation. I'm face to face with myself," he told AFP in an interview.
"It's something that I find hard to find elsewhere and that's what keeps me going."
Alain Robert, a 62-year-old French climber who became a legend by pioneering high-risk city ascents, is of course a huge inspiration, Leduc said.
"I really respect him for his performances," he added. "He's someone who pushed the level of climbing in the '90s and he's the first person to have undertaken such extreme and random solo climbs."
Robert, dubbed the "French Spiderman", became rich and famous by climbing the world's tallest buildings, and Leduc is trying to make a living out of his passion, too.
On a recent afternoon, Leduc scaled the Franklin Tower, a 115-metre (377-foot) -high office skyscraper located in Paris's La Defense business district.
Like Robert, he performed a free solo climb, using only his feet and hands to move himself upwards.
A small bag of climbing chalk powder was fastened around his waist, and he sometimes paused to dry out his hands.
When he reached the top of the tower he raised his arms aloft in triumph.
'Childlike spirit'
"It was such a good feeling. At the beginning it was long, it was a bit hard to get into it," he said afterwards.
"After a while, halfway up, I didn't count the floors, but then it went really smoothly and frankly I went really fast to the top," he said with a smile.
The climb however took a toll on his hands, with Leduc proudly showing off fingers injured during the feat.
"I hadn't anticipated that I was going to end up with bloodied hands," he added.
Several police officers waited for him on the ground but let him off with a warning.
Urban climbing is illegal in France and can result in a fine or stiffer punishment.
But Leduc brushes off such concerns. "When I set out on this kind of performance, I expect to be stopped at the end. But that's secondary, really," he said.
"I know that there could potentially be problems later on."
Leduc has been climbing since he was a child.
"I've been climbing all over the place, climbing trees, climbing everywhere," he said.
He started climbing buildings in his hometown Nancy when he was 19. "Little by little, I diversified. I really got into the big urban projects, skyscrapers. "
His parents have not accepted what he does, even though he has tried to make them understand the appeal.
"There's a lot of conflict with my parents. We're not on the same wavelength," he said.
"There is still work to be done to get them to accept it. Which I obviously understand."
But he said he did not take unnecessary risks and climbs only when he is fully ready, physically and mentally.
"I'm looking for ways to push myself a bit," he said. "But I know my limits and I try not to exceed them. Otherwise that's where it gets really dangerous."
Urban climbing was also "pretty," he added.
"It's great to see a human figure climbing up a smooth facade like that. I really like the artistic side of it."