London's tall buildings: the only way is up

Its shape is already a landmark on the London skyline, which has been transformed over the past decade or so by a host of trophy towers. And there are more to come. According to data published by New London Architecture (NLA) and GL Hearn in April, 510 towers are planned for London, with 115 schemes already under construction – a record number.

So why has there been such a sharp rise in the number of tall buildings and, as the City of London corporation prepares to assess the future of its ‘Eastern Cluster’, what does this mean for London’s skyline? Will the capital continue to aim high – or will its towering ambitions be thwarted?

It is easy to forget that until relatively recently, St Paul’s Cathedral was London’s tallest building, as it had been for the best part of 700 years. It can thank its good innings on the combination of London’s soft clay soil, which made it hard to build much taller, a legal system that prevented people from building taller, a planning system that protected views of the cathedral and an economic system that didn’t yet offer incentives to build tall.

The system protecting views of St Paul’s from eight vantage points scattered around the city remains in force. Originally nothing more than a gentleman’s agreement established in the 1930s, it has since become legally binding.

However, the London Building Act of 1894, which limited the heights of buildings to less than 80ft, has long since been revised and today, it is a ceiling introduced by the Civil Aviation Authority (CAA) that limits the height of London’s buildings, according to flight paths.

It was these regulations that scuppered the original plans for the tower formerly known as the Pinnacle. Back in 2005, the plan was for a 307.5m-tall tower, which would have been the tallest building in the UK, but the CAA nixed it.

The development was subsequently chopped down to a still sizeable 288m, but then the US subprime housing bubble burst, kickstarting a global economic recession that resulted in property investment drying up. The project was mothballed in 2012.

Three years later, AXA Investment Managers – Real Assets acquired the site and in November, the firm and its joint venture partner Lipton Rogers were granted planning permission for a more modest 278m-tall scheme.

Rights-of-light battle

There were still obstacles to overcome, not least a battle with locals over rights of light. However, the developers won out in 2016 and in October of that year announced that they were taking the project forward. They also submitted and then withdrew a plan for a shorter tower, reverting to the 278m-tall scheme that will be topped out at some point next year.

Meanwhile, The Shard was about to assume the mantle of tallest building not just in London, but the country and the continent. Although there was an issue concerning protected views over St Paul’s, in the case of the Sellar Property-owned, Renzo Piano-designed skyscraper, it was decided that the protected views system did not mean The Shard could not be part of the view; it just meant The Shard could not obstruct the view. This interpretation has paved the way for other London skyscrapers – if they can work around another idiosyncrasy of the legal system that has historically stunted the height of London’s buildings.

Rights of light affect the shapes and designs of tall buildings. The legal rights granted to some buildings for access to certain amounts of daylight are not determined by one particular piece of legislation; they have been established over years by case law.

In 1904, Colls v Home and Colonial Stores established that a tenant has a right to “sufficient light according to the ordinary notions of mankind for the comfortable use and enjoyment of his house”. In an attempt to establish what exactly this meant in practice, Percy Waldram wrote a series of papers during the 1920s.

Daniel Maddox, associate partner at GIA, says: “He considered that sufficient light required a person to be able to read the small print of The Times from one foot away. According to him, this equated to one lumen per square foot.

“Waldram then calculated that to achieve one lumen per square foot within a room, that area of the room must be able to see at least 0.2% of the total sky dome through the window on an overcast day. This has since been used by the courts in all precedents since.”

According to Maddox, Waldram’s definition is “generally accepted to be a poor way of assessing what is deemed sufficient”. However, he argues, as London’s skyline becomes crammed with ever-taller buildings, this odd definition of rights of light will become “a main consideration for most when looking to redevelop sites in central London”.

This presents a paradox for London. “The housing shortage in London requires density to increase significantly from where we are,” he says. “However, rights of light are frequently at odds with increasing density, with large potential payments that damage viability leading to developers not maximising the potential of development sites.”

It is a problem that will need to be resolved because the reality is that with developers running out of space to build on, the only way is up. “Land prices as they are, buildings are only going to get taller,” argues John Munday, managing director of Paragon. “It’s kind of inevitable.”

Paragon director Matthew Dunn agrees and adds that the difficulty of getting planning permission gives developers an incentive to build as tall as they can with the limited space they have. “If developers get planning permission to build vertically, that’s a quicker solution [to the land price problem],”he says. “And they can get a quicker return on their investment.”

Another advantage of tall buildings is that they are easier to develop than shorter or more spread out schemes, says Kamran Moazami, managing director of property and buildings at WSP, the construction engineer on 22 Bishopsgate. Rather than having to bring materials and labour to a huge area, you bring them to a small area and build up, he explains.

They are also more sustainable, adds colleague Ross Harvey, WSP’s technical director of structures, pointing out that when people live closer together, they generally have a smaller carbon footprint.

Balancing act

Sometimes tall buildings are simply the only option as well as the best one.

“Affordable buildings in London have to be tall because of land prices,” contends one planning legislation law expert. “It’s not quite the economics of scale because it’s expensive to build taller, but on the other hand, you can charge more for the property, because the view is seen as valuable. So the whole thing is a balancing act.”

However, there are downsides to building tall. In 2013, the Walkie-Talkie was heavily criticised for reflecting the sun’s rays and melting the bumper of a Jaguar car in a nearby street, and schemes have also hit the headlines when intense winds bouncing off them have knocked over people and objects.

Then there are those who just do not like the look of tall buildings. Pressure group the Skyline Campaign argues that London’s heritage is being permanently damaged by tall buildings and that ugly, generic tall buildings will turn London into a “bad version of Dubai”.

We need to get creative if we’re going to tackle London’s housing crisis with taller buildings

Peter Barbalov, Farrells

With as many opponents as advocates, it is no surprise that many tall buildings don’t make it beyond the drawing board.

Another issue that has come to the fore since the Grenfell fire tragedy is safety. “Most opposition to tall buildings in London comes as a result of Grenfell,” one expert comments. Paragon’s Munday agrees: “As we build taller, Grenfell is going to have even more of an impact than it has already.”

Time to adapt

The regulations developers currently abide by are basically an evolution of those introduced after the Great Fire of London, which were conceived to stop the spread of fire from building to building. Munday believes that regulations need to adapt to the fact that as well as spreading out horizontally, London is getting taller.

Darren Wood, director of security consultancy at Cundall, has spent years analysing the potential dangers of all kinds of buildings. “With a project like 22 Bishopsgate, the challenge is getting thousands of people into the building in a timely manner – because they’ll want to be at their desks in 10 minutes – but also in a safe manner,” he says. “Then you need to find a way to get them out again safely without using stairs.”

There are other safety challenges that many people won’t have considered, he adds.

“The ground-floor security becomes even more important as buildings get taller,” he says, noting the taller the building, the bigger the target for terrorists.

Given the concerns over terrorism, lack of available space, rights of light and London’s skyline, the challenge for developers in London becomes how to create a development that is simultaneously tall, safe, financially viable and aesthetically pleasing.

It is a challenge that architects such as Farrells design partner Peter Barbalov have embraced. “London is challenging from an architectural point of view, but this is what makes my job more interesting and more creative,” he says. “We need to get creative if we’re going to tackle London’s housing crisis with taller buildings. Rising to this challenge is a matter of how good we are as professionals.”

The good news is that there seems to be a real desire to make things happen. The upshot is that the whole process is becoming more straightforward. Comparing his experience working on The Shard 15 years ago with his experience working on 22 Bishopsgate today, Moazami says the latter has been much easier.

With the housing crisis not going away any time soon and demand for new office space only growing in London, the hope is that whatever challenges are thrown at developers, they will continue to rise to the tall building challenge – and that a Brexit-shaped spanner is not thrown into the works.