One London is the City’s new super-tall building – here are all the design questions answered
One London, the upcoming tower formerly known as 1 Undershaft, is set to become the UK capital's joint tallest building, reaching as high as the Shard; we spoke to its architect, Eric Parry
One London is not simply another tower in the City of London. Upon completion, come 2033, this high-rise, formerly known as 1 Undershaft, is set to rival the Shard, becoming the UK capital's joint tallest building, its developers, Aroland Holdings and Stanhope, emphasise. This is no small feat – and the ambitious scheme's architect, Eric Parry, also highlights his design's provision for extensive publicly accessible green spaces, carefully planned environmental performance and amenities, including the highest bar in London and an 11th-floor public garden.
One London – the capital’s newest high rise
Construction is planned to start in 2028, and the numbers are impressive. The tower reaches 309.6m high and spans 74 storeys (the London Museum will operate education spaces on the top two, for school children and young people to learn, experiencing London from on high). The project's creators are also exploring BREEAM and NABERS UK rating frameworks for its sustainability credentials, and underline that its landscape strategy 'delivers a 960 per cent Biodiversity Net Gain'. But what does this mean for the capital? We spoke to Parry about what is aiming to be the future tallest building in the City of London.
Eric Parry on One London
Wallpaper*: Let's start with the basics – what is One London?
Eric Parry: Well, first of all, it has to be said that the building is the centre of the Eastern City Cluster. That's an interesting concept, because it's a very English one, this sense of a cluster of buildings that relate to a landscape idea, placed as sort of foothills, as if one's looking at an image of landscape. It is completely different to the way in which tall buildings are conceived in Canary Wharf or Frankfurt, or Paris at La Defense. They're closely bound. One London will be at the cluster's heart and that has been part of the ethos of this building, having a certain dignity, carrying with it a lot of responsibility for being in its position.
W*: So you speak about clusters, tall buildings. We're in the City; is the building office space, or mixed-use?
EP: The majority is commercial workplace, and that's incredibly important for the 7,000 to 10,000 people that will be working in the building. But at the same time, I think there's a spirit of generosity in it, which is really important. So, from the outset, I had a vision for the top of the building to be civic rather than commercial.
W*: That is very important, and it also sets it apart from similar tall and super tall buildings. Would you like to tell us a little bit about the brief? How did you balance commercial needs and architectural and urbanistic vision?
EP: This is the 11th year of working on this project for us. It was a competition, and it had a pre-Covid life as a proposal that was much more a plaza with a tall building. After the pandemic and the City of London Plan for 2040 [approved in 2024], there was a realisation that there's a massive problem with supply [of office space in the City]. There was a need for space, but also for breathing space, for access to air and the environment, to get away from the sealed box, which gave rise to this idea of a building that works on multiple horizons in a way that really is beneficial to the wellness of the occupant.
W*: It sounds like there were different iterations and the design evolved a bit over time. Was it always meant to be this tall?
EP: Oh, yeah, it was always up at the centre of the cluster.
W*: Did the height itself attract you; was it a challenge, an opportunity? I know your studio, and you, often undertake large-scale projects, but not necessarily super-tall.
EP: There was no sense of muscular desire in the height, particularly. But I think there's a real interest in the complexity that height brings. And then, of course, there is the thing about the sky. In lower buildings, architecture is about the urban block, about streets, about squares. A tall building is about the skyline; you address the clouds, the weather. There is something incredibly important about the way a building develops from the ground and reaches to the sky.
W*: Agreed. And there are different ways a building is experienced from afar and from up close. How did the very famous buildings around the site factor into your design development?
EP: You know, this iteration is very similar in height and in various aspects to the Eiffel Tower in Paris. Towards the bottom, the Eiffel Tower has this deck above the great arches and the deck here, which is public at the 11th floor – an amazing set for the public, an amazing set of new views of that very precious surrounding. I didn't want to do another sloping glass surface.
W*: Tell me more about the public spaces and the special place for the London Museum and the education spaces at the top.
EP: We made a deal with them. From a personal point of view, I took my own child's class up the Heron, when it was completed but not occupied, to look down on the city they dwelt in. And that was amazing. They all remembered it, you know, and I thought when we were dealing with this, let's do this here. So every school kid should get the opportunity to go up to the top of the building and see the view.
W*: There is something to be said about the democratisation of that space, because traditionally, you would have the tallest point of a tower, and it would signal maybe corporate wealth or power. But now it's open to everyone who wants to use it.
EP: That has also been reflected at the ground, of course, because the ground has two sides, actually. There is the 11th floor, the public garden. And the eastern side has this great reception space, the celebration of entry, I would say. It's incredibly levitational. The proposal has an expression of structure. The pillars I like to call the 'giant redwoods'. They are huge, made of weathering steel and slim like a beautiful tree. They branch to support the garden, but they also continue to support the 300m up. So this huge building comes to the ground in an incredibly light way.
W*: Your work, for me, is associated with craft and attention to material and detail, and everything on that ground level speaks to that. There is also an elegant restraint overall; it's not flashy.
EP: Thank you. I didn't want to make another building all in glass with a closed cavity system with blinds that come down. We wanted it to be passive, with shading. It is very high performing, and I wanted it to be white, not glass. This also has to do with longevity.
W*: Let's talk about that too, and about sustainability at One London.
EP: There are very few buildings over 200m that are ever pulled down, so there's a responsibility. This is going to be there, perhaps, as long as the Tower of London. I've got a bit of an obsession about biodiversity and planting, so we like to practise what we preach. With One London, there's a 1,000 per cent increase in terms of biodiversity from the existing site to this. Urban greening is very important, and we have shaded, hanging gardens. There's a great mix in the building that allows it to rise with great confidence from a beautiful ground plane. I have seen from past projects the joy a beautiful garden can bring.
