Race For The Skies: How Zhang Yue builds skyscrapers at jet speed

Cities in China seem to spring up almost overnight, but building a 57-storey tower in just 19 days is impressive even by their own high standards. For a new BBC World News documentary, Race For The Skies, I have been to Changsha to meet the man who aims to revolutionise construction with his new, speedy method of building.

Zhang Yue is a difficult man to unpick. Leaf through the Chinese press and you'll discover a wealth of contrasting facts about him, jostling with one another in an unlikely coalition.

That he, for example, is a self-taught engineer who made his millions selling air-conditioners. That he's also a committed environmentalist with a fierce moral code. That he puts all new recruits through a week's intensive military boot camp. That his expansive grounds house a replica of Versailles and a huge gold pyramid. That he was the first Chinese civilian to own a private jet. That he eats only one meal a day. That he loves Plato. That he commands absolute respect and loyalty amongst his 4,500 staff. And that he started his career as an artist.

I want to know what makes him tick. So I've come to visit his company Broad Group, in the city of Changsha in Hunan province, to film him for a BBC World News documentary as he conducts his grandest project to date: a 200m "instant skyscraper". It's to be made in a factory and then slotted together on site, like Lego. Doing things in this modular way, he says, is not only quicker, but greener and safer.

But even this undertaking is nothing compared to his master plan - to build the world's tallest tower: an 838m behemoth called "Sky City", in just three months. The incumbent took five years: the 828m Burj Khalifa in Dubai which may be forgiven right now for glancing anxiously eastwards over its slender steel shoulders. As our documentary's title suggests, this really is an engineering "Race for the Skies".

So now, after a year of research, emails and phone calls, after a week in Changsha touring his pristine factories, meeting diligent staff, and eating well in his organic canteen, I'm finally about to meet the man himself for the first time. Winning him over will be crucial to a successful film. It's almost 7pm on a Wednesday evening. I'm a bit nervous.

"Finn, welcome. Listen, it's late and I've not eaten today. I have to go home for dinner." My heart sinks.

"Please join me," he offers, with a roguish smile.

And like that, we're in his car - an environment-friendly Tesla of course - as he drives me through his company town. Broad Town is a 100-acre park dotted with dorms, farms and factories. He drives fast, clearly enjoying the power of his car. We pass his fleet of limos and his helicopter - it's in the hangar - too "fuel-hungry" to justify pleasure flights. Suddenly, he brakes hard and throws an aggressive right past a gaggle of geese onto a side road that leads to his villa.

"You can't do it like that. Way too much salt! Give it here."

We're now in his kitchen and Zhang Yue is giving his maid short shrift on her culinary skills. He takes over frying the fish himself, and I hover awkwardly, clutching a glass of Spanish rioja, thinking up topics I know he's interested in: Monet, Laozi, wind energy...

The fish is good; it's from a local farm. Eating well is paramount in China, and Zhang Yue feeds his employees handsomely. Three hot meals a day in the canteen, prepared by skilled chefs. But if staff dare waste "a grain of rice, a drop of wine, or a crumb of your food", as a metal sign on each table warns, they're banned from eating in the canteen for two days and fined $30.

Most staff come from near Changsha, the provincial capital where morning mists from the Xiang river swirl and mix with smog of the city. It's a place famous for its spicy food, including Mao Zedong's favourite - twice-cooked pork. Mao was born in these parts, and is revered here.

But it's another Chinese leader who takes pride of place in Broad Town - a statue of Deng Xiaoping, the man who reformed and opened up the economy in 1978, stands outside the palace. Broad Group's chairman is one of a generation of entrepreneurs who seized the brave new world with both hands.

Back in his dining room, his family have now joined us at the table. I find myself fielding friendly, but personal questions from his mother, wife, son and sister. I realise that he's interviewing me as much as I'm interviewing him. All in the name of the film, I think to myself, taking another sip of red.

The house isn't opulent, but confidently decorated by a man whose company is one of China's most successful. Boilers, air conditioning and air purifiers might not sound the most glamorous of products, but Broad Group's focus on quality and eco-friendly features have opened markets for them in more than 80 countries, and left Zhang Yue with an estimated fortune of $900 million.

I tell him I've just been inside his new tower. It's already impressive: they're about halfway finished, 30 storeys of steel skeleton hulking intently on the horizon. I tell his family how I enjoyed watching the hundreds of workers dressed in blue overalls climb all over the building: slotting, bolting, welding. How everyone has a purpose and things appear meticulously ordered - like an elaborate ballet.

We've now put a good dent in our second bottle of red, and the rice wine has made an appearance. This is going well. I anticipate a good session of filming the next day.

Just then my phone vibrates. It's my editor in London - I hadn't expected to still be talking to Zhang Yue this late and we'd planned to catch up.

But whether to pick up? I decide it's best to answer and tell her to call back. Can't hurt.

As I turn my body away, from the corner of my eye I see Zhang Yue getting up and leaving the table.

I turn back after the call - it lasted no more than 10 seconds. We continue eating, somewhat less boisterously than before. Zhang Yue doesn't return. He doesn't return all night.

After we finish up the meal, I make the long walk back through his campus alone. I've blown it. How could I have had the nerve to answer a phone call in front of this guy? I claim to know about Chinese culture, and I've made a big faux pas here.

But next morning, his assistant calls. Zhang Yue is in good spirits. It turns out he'd gone back to the office to work. Lots to do. If you want to build towers as fast as he does, you're going to expect a little overtime.

(Finn Aberdein's interview with Zhang Yue can be seen in Race for the Skies, to be broadcast on BBC World News on Saturday, June 13 at 09.10, 21.10 GMT and Sunday, June 14 at 02.10, 15.10 GMT.)