Why Do London Skyscrapers Look Like That?

London has some seriously odd looking skyscrapers

with some very unserious nicknames,

The Gherkin, the Scalpel, Can of Ham,

the Cheesegrater, the Walkie Talkie.

But buildings this large and this expensive

in the heart of one of the world's most important cities

don't just happen by accident.

So how did these skyscrapers

end up with such unique designs?

I'm Nick Potts, I'm an architect,

and today we're taking a walking tour

of London's most interesting skyscrapers.

[bright music]

To understand why these buildings look the way they do,

first, we need to understand three major factors

about building in the city of London.

First, unlike some other major cities around the world,

London doesn't have a uniform street grid.

Each lot has a unique shape and unique dimensions.

Some lots are rectangular,

others are triangular, some are just bizarre.

Secondly, in addition to,

or maybe because of these irregular lot sizes,

what gets built on them

is subject to a huge amount of negotiation.

In a city like New York,

there's a defined buildable envelope

that regulates the bulk, the shape, the size,

the height of new buildings.

London doesn't have those sorts of rules,

so every new large building

that impacts the skyline is up to negotiation.

And the third factor is that,

within the square mile of the city of London,

there were no skyscrapers until the 1980s.

Before the 1980s, nothing this tall could legally be built

in the historic square mile of the center of London.

[Narrator] We are right over the center

of the hub of the world, the city of London.

No view of London would be complete

without a view of Sir Christopher Wren's master work,

Historic Oath St. Pauls.

These buildings only started going up

when those laws were changed,

and actually the political organization of the city changed

to enable it.

And so for the first time

with the creation of the greater London Authority,

London had something it hadn't had before, a mayor.

And given the trend towards globalization

that was occurring,

the New London plan saw the opportunity to cement London

as a global financial capital with a downtown.

So in the London plan,

there's no clear definition about what a tall building is,

only a somewhat puzzling statement about,

The higher the building, the greater the scrutiny.

But they did, however, create a framework

of five major tenets

that would feed into the approval process

for any major tall building,

the functional impact, the visual impact,

the cumulative impact,

the environmental impact, and public access.

[bright music]

This is 30 St. Mary Axe,

known to many as the Gherkin

because it looks like, well, a pickle,

but there's actually a good reason why it looks like this.

This was designed by Lord Norman Foster

and completed in 2001.

This was designed to be a symbol of sustainability.

And 30 St. Mary Axe really leaned into the idea

of environmental impact as the path towards approval,

simply through its formal massing,

the rounded shape, the curves

minimize wind at the base of the building,

which was a really crucial thing

for the regulatory agency to get behind.

And the second of these was really about

the performance of the building

in terms of environmental responsibility

and trying to minimize the use of fossil fuels

to heat and air condition

in the way that you typically would in a glass-enclosed,

rectangular skyscraper.

So if you look at the black stripes running up the building

within those are multi-story atriums.

And these were meant to allow airflow to move up

and through the building, almost like a chimney.

And in addition to that,

there were windows that were designed to open and shut

to allow air to move in and through the building,

minimize the use of air conditioning.

Also, if you look closely at the building,

you don't see any louvers,

and they achieved this shape and this sleekness

by actually moving the cooling towers

and the heating plant to an adjacent six story building.

So even though the building communicates sustainability,

its performance is still very much traditional

and just hidden.

[bright music]

This is the Leadenhall Building,

which some people have taken to calling the Cheesegrater.

This building was designed by Richard Rogers and Partners,

and it was completed in 2013.

The design here might look like an odd choice,

but it makes a lot more sense

if you look at it up against another building.

St. Paul's Cathedral is just a few blocks away,

and the shape of the Leadenhall Building is

actually a gesture of respect

looking back towards St. Paul's Cathedral.

So thinking back to the approval guidelines

in the city of London for a tall building,

the visual impact is one of these core tenents,

and this is the one that the Leadenall Building

really leaned into.

Across London, there are these protected view corridors,

essentially making sure that St. Paul's is visible

from various vantage points

across the entire metropolitan region.

And these view corridors,

in the approval for any tall building,

need to be kept clear, both in front and behind.

[Narrator] Working on top of London's tall buildings

is not the most comfortable of jobs.

But when the sun shines and the air's clear,

the views around and below are well worth compensations.

Looking across London,

St. Paul stands out with proud dignity.

So the Leadenall building

by leaning away from one of these protected viewpoints,

freed up one of these views

and it enabled the building to be quite tall.

And there's also a somewhat interesting parallel

with this building and another building by Richard Rogers

just a few streets away, the Lloyd's of London headquarters,

which is almost an extreme version

of an inside out building with exterior stairs

and a fairly wacky exterior shape.

Leadenhall building kind of simplifies this,

it's almost like a mature version of the same sort of idea.

You have your very functional office floor plate

with all of the mechanical guts stuck on the outside of it.

Over here it's only on one side

to essentially maximize the efficiency

of these rectangular floor plates

as opposed to Lloyd's, which is a little bit more artful

and composed with the distribution of stairs and duct work.

And this is a very British through line

of modern architecture, going back to,

you could even say the Crystal Palace in HydePark in 1851,

which was this exploration of metal and glass

and this sort of techno futurism of British architecture

that that building really started.

But while the Cheesegrater gets smaller towards the top

to preserve these historic sight lines,

the next building we're going to look at

turns that idea upside down, literally.

[bright music]

Behind me is 20 Fenchurch,

which some people have taken to calling the Walkie Talkie.

And this is one of the only skyscrapers in London

that you can actually visit the top of for free.

That is if you can get a ticket.

The building was designed by Rafael Vinoly,

it was completed in 2015.

And if you notice,

the top of this building is larger than the base,

which is quite unusual for a tall building.

But these curves are not about preserving historic views,

this design is actually a clever way

to create a public space

within the footprint of a private building.

In the London plan,

there's actually a requirement for public space

and the magic here is that

they've managed to create a total area of public space

that's actually bigger than the lot that it's built on.

Directly underneath the almost dome

at the top of the building is public part.

So it's actually interesting that the top of the building

is the size of the lot and the bottom is smaller.

It's the opposite of what we're used to

when we think of tall buildings

that gets smaller as you ascend.

And because of this essentially trick of geometry,

there's about one and a half times

the amount of public space than the lot even contains.

One of the other aspects of the visual metrics

for any tall building getting permission

for the London plan is actually design quality.

Because there wasn't a set visual metric

that this was assessed against,

what the developers ended up doing

is actually hired other famous architects,

including Jean Nouvel, who did not design this building,

to essentially write an ode of praise

towards the building design

saying, This would be a contribution

to generations of Londoners to build this,

quote-unquote masterpiece.

And this is just a small bit of what it takes

to build a skyscraper in a city like London.

[bright music]