“When we see increased density, we immediately think of the need for something more than occupied space, sold space, work space, living space – something more public or collective that could animate such a mass of habitation or work,” says James von Klemperer, president and design principal of Kohn Pedersen Fox Associates.

Creating Vertical Cities

The ideal is to infuse large structures with a series of places where people could wander or congregate, just as they would in a city streetscape, “to create a very complex, inviting and interesting set of sectional experiences”. In mega-projects, architects can create ‘vertical cities’ by taking advantage of the gaps between different uses to create gathering places. KPF’s JR Central Towers project in Nagoya put almost 5 million ft2 of retail, office, hotel and public space stacked on top of a bullet-train station – it holds a Guinness World Record as the largest station building in the world. There is a range of public and outdoor spaces throughout the building, as well as Sky Street – a huge concourse on the 15th floor of the podium joining the two towers, which offers panoramic views to anyone who takes the elevator from the station.

“Part of the challenge is to show the vertical transportation in a very visible way at the front to bring people up naturally,” says von Klemperer, “so that they feel not compelled but interested in achieving these higher levels where they could do things not necessarily programmed by their rental agreements but by some sort of public street.”

At Hysan Place in Hong Kong, another mixed-use scheme of 716,000 ft2, the building is conceived as a series of shifting forms to create a series of vertical gardens over the height of the project. Here too, the escalators are clearly expressed on the outside of the building, zigzagging up the façade and “beckoning to the crowds to find retail space at the upper levels”, says von Klemperer.

“It’s finding opportunities to make spaces. The melange of tunnels and walkways that go through this project becomes a sort of jungle gym for a series of truly public spaces through this mixing chamber of retail, and ends up in pockets of space above that are semi-public. So there’s a pallet of interior spaces that animate this sectionally articulated piece of the city.”

Multitude of Uses

It’s not easy to create genuinely public spaces in mega-projects – but it can be done. KPF’s design for the 555m Lotte World Tower in Seoul includes a cultural centre, kids’ park, jazz bar and aquarium as well as a 2,000-seat concert hall, which will be the home of the National Orchestra of Korea.

“It’s not a piece of commercial formula, it’s mandated by the city,” explains von Klemperer. “But the point is that it is possible to provide truly public space of a civic sort within the complex section of a high-rise building.”

“A mix of facilities is important for keeping highly skilled workers in cities as they grow older,” adds Steve Burrows, executive vice president at WSP in San Francisco. “We need to consider all the things that make a living city,” he says. “Sport for example – are stadiums civic buildings? Should they be downtown? And how do hospitals and schools fit into vertical cities? In order to capture families, something’s got to change. How are our cities going to become liveable for people throughout their entire life cycle?”

Building Community

One of the phrases von Klemperer uses is “building community” – a concept that will become more and more relevant as the life of towers extends throughout the day and night and people spend increasing amounts of time in high-rise developments. This is something that Woods Bagot has also been considering in the context of the vertical campus. “You have to think about what makes a strong community,” says global workplace leader Steve Hargis. “It’s not just an office – you have to supplement that with all the services and experiences that people need.”

In the design of these buildings, he thinks that the role of architecture crosses over into urban planning. “We are in the middle of an unprecedented migration to urban centres, so it’s up to us as a profession to build something that is sustainable, where people want to be, that supports the kind of community life that we’re all looking for.”