St Paul’s long influence on London is testament to the importance of getting tall buildings right says the author of a strategic design guide
On September 2 London marked the 350th anniversary of the outbreak of the Great Fire of London. The fire erased over three-quarters of the original City and about a quarter of the wider city. As we know, it was then rebuilt to higher standards and refreshed proportions. It took Wren 40 years to rebuild St Paul's Cathedral, which opened in 1711. On its completion London certainly had a huge and extremely tall new building, clearly shown in Canaletto’s famous painting of 1745. The fire damaged the fabric, but not all the other things that made London great.
Nigel Clark and I recently updated Tall Buildings – a Strategic Design Guide. It was first produced in 2005 at the time of the Gherkin. Ten years on and the City of London skyline has undergone significant change. New buildings include the Shard, at 306m the tallest in the UK,122 Leadenhall (Cheesegrater), 20 Fenchurch (Walkie Talkie) and 110 Bishopsgate (Heron Tower), among others. Critically, all these buildings have won consent through a complex planning and stakeholder consultation process. The late Paul Katz, managing partner at architect KPF, claimed achieving planning consent in London was 10 times tougher than New York in 2014. To be different by that order of magnitude says a great deal about the processes and procedures to be navigated by the investors, developers and design teams.
In the book we examine all the issues associated with tall buildings. The first three chapters are about why we need them, who builds them, who occupies them and what influences their location in a city. The middle of the book discusses the issues of design, appearance, engineering and cost. We also consider the special nature of construction and the reality of legacy and possible deconstruction. Finally we take a look at the future with a vision of tomorrow’s skyscrapers.
This is important, with much debate around the role of tall buildings in London, New York and beyond. A recent article critical of super tall buildings, by Elizabeth Diller of Diller Scofidio + Renfro, architect of New York’s High Line, focuses on height difference in isolated locations combined with reduced areas and quality of urban space in New York. Do we face the same issues here? The London skyline is being actively managed in three ways to avoid this scenario: policy frameworks, public realm policy for tall buildings, and localised masterplanning.
In London each borough has a tall building policy framework. These fit into an overall approach set out by the Mayor’s office. Developers can therefore see where taller buildings ('densification') are likely to be welcomed and where opportunities are restricted. These frameworks also take into account long distance views and local views of key city features. St Paul’s is perhaps the best known and a defining constraint on positioning of a new tall building. It is also the case that as a result of flying restrictions a maximum height – effectively the Shard’s at just over 300m – is imposed in London. Unless we change the location of our London airports we will not rise to levels such as the 426m of 432 Park Avenue, New York any time soon.
In recent years there has been an increasing requirement to ensure that these tall buildings give something back to the public realm – a sense of amenity and value for everyone, not just the occupiers. At the Shard there is a new bus station, station forecourt, tube link and top quality landscaping. At the Cheesegrater there is a vast public space beneath the building responding to pedestrian desire lines and a sense of shared environment for everyone. The building is saying ‘come in’ rather than ‘keep out, this is private – employees only’. At 225m high and only just outside a viewing corridor to St Paul’s, it’s definitely tall and a great addition to top quality buildings in London.
Elizabeth Diller referred to the masterplan at Hudson Yards, Manhattan, as a better model for development. ‘It was planned, with logic,’ she said. This has parallels in London at Canary Wharf, Battersea south of the Thames and at Stratford to the east around the 2012 Olympic Park. In all these locations special effort has been expended to define height and densification targets, address transport and infrastructure needs, create viable places and respond to leisure, housing and retail needs. Hudson Yards contains all these ingredients on a grand scale and already has a new subway connection to enhance connectivity further.
The ways that cities manage a skyline is a complex mix of technical, commercial and political judgements. Technical engineering advancements have enabled the current rush of super-tall and slender buildings in New York. For the aforementioned 432 Park Avenue we at WSP | Parsons Brinckerhoff achieved a height to width aspect ratio of more than 15:1. Residential property values are so high in the city that the technical and construction challenges can be overcome. The political will and consent framework must also be supportive of such activity otherwise the structures would not have been built. It is only the latter control mechanisms that can safeguard the city fabric. Creative engineering and a demand for residential property has pushed the skyscraper capital to even further heights. Going up is Manhattan’s identity, so creating subjective height limits could prove counterproductive in balancing the skyline’s fabric.
It is also worth considering that in the ‘history of the world’ only four buildings taller than 150m have ever been deliberately demolished. Tall buildings are immensely strong and robust. They have to be able to resist wind and earthquakes as well as their own significant weight. This means that virtually all our tall buildings are going to be on the skyline ‘forever’. This also means we should not rush when designing them. Our decisions in design will have a lasting legacy that we cannot afford to get wrong. St Paul’s has been in place for 305 years. There is no reason for it not to be there in another 305 years. Wren’s masterpiece continues to inspire our skyline and it will hopefully continue to exert some control over the fabric of London for the foreseeable future.