Diamond life

Newfoundland, the first residential project in Canary Wharf – and London’s tallest build to rent scheme ­­– has been completed, and it’s an architectural landmark in its own right. Lead architect Billie Lee spoke to Jack Wooler about its distinctive structure

The first residential building on the main Canary Wharf estate was completed this spring. At 218 metres, Newfoundland is a prominent addition to London’s skyline, and currently the tallest purpose built build to rent apartment block in the capital.

Designed by Horden Cherry Lee (HCL) for Vertus, the residential arm of the Canary Wharf Group, the project has been hailed by its owners as an “architectural and engineering masterpiece.” This is largely based on the external diagrid structure, which allowed the team to overcome challenging site issues while making the building a recognisable landmark across the city.

Rising 58 storeys, the building contains 636 apartments, ranging in size from studios to three-bedroom family homes. Vertus intended to stand out from the competition by kitting the building out to a standard that would make it “the pinnacle of the BtR sector.” This is manifested as a certain level of luxury plus 13,000 m2 of amenities which should appeal to its demographic, including rentable gaming and dining spaces, fitness studios and even ‘wine dispensers.’

Situated on the western edge of the Canary Wharf estate, residents have been able to snag a prime dockside setting – and be able to walk the length of the dock to the underground station away from traffic. They will also enjoy many restaurants, bars, shops and events spaces situated minutes away from their home.

The scheme has been designed to save over 8,000 kg of CO2 emissions with the installation of PV solar panels on the roof alone, and it also features a variety of wildflowers to bolster biodiversity in the estate.

Setting a precedent

Founded in 1993, the Canary Wharf Group has taken great strides to regenerate what was a deprived area, and owns nearly 100 acres of property at Canary Wharf as well as elsewhere in London. They have over 1,000 staff working 24/7 running the Wharf day to day, including landscaping, arts, events, and even security – and have been central to transforming the area into the major business district it is today.

While the group’s new residential ‘neighbourhood’ (the adjacent Wood Wharf) has created housing in the area – including the Herzog & de Meuron-designed One Park Drive – Newfoundland is the first scheme to be granted residential consent in the central business zone itself.

The site had previously been zoned to allow a tall building to be developed, but it had reportedly been overlooked for redevelopment as it had been considered too small to make an office scheme viable. Equally, a previous planning permission for a 140-room hotel wasn’t able to be brought to fruition.

When HCL were brought on to the project in 2010, they were tasked with converting the permission – which was “not making the most of the zoning it benefitted from” – and to maximise the site’s potential.

“Building heights in the area were only governed by London City Airport, and so this was clearly an exciting opportunity – and a tower was the clear choice,” says Billie Lee, lead architect and director at the practice. “It was obvious from the outset that this tower would be residential, being the most financially viable option, making the best use of the footprint, and having the benefit of introducing housing to the area.“

He tells ADF this idea was well received: “Everyone was keen to deliver homes in the heart of Canary Wharf to make it a more socially sustainable community.” He says the London Planning Authority “warmly welcomed” the proposal.

Challenges & opportunities

Besides the potential to design a tall building, Lee explains that the site offered significant opportunities, including the “naturally generous” public realm around it, its north-south site orientation for optimising daylighting, and open views to the east and west. “Of course,” adds the architect, “it had its landmark location next to the river, and its high visibility.”

The site did however also come with a number of constraints, including being next to the listed dock, its compact size, irregular shape, and the fact that its western position leaves it exposed to the elements. Lastly, and “most importantly, there are two London Underground tunnels running directly below it.”

These Jubilee Line tunnels were the key design issue to contend with from the get go, and ultimately prevented the structure rising as high as initially desired. “As they converge towards the station,” Lee explains, “they create a V-shape directly under the site, limiting options for ground piling in the narrow space between the tunnels.”

He says that while a standard central core plan would have been “the most efficient building layout” for a high-rise building, this would have meant the core would be placed directly over these tunnels.

In order to work out how to tackle this conundrum, the team established the maximum piling capacity possible – including the prospect of working into the exclusion zones around the tunnels. An agreement was struck to work within restricted areas but also certain times – and, with commitments to Transport for London to carefully monitor the effects of the works, they were given the go ahead to begin.

Braced tubes

Lee explains that with the limited ground bearing capacity around the tunnels, “it was clear that the construction would not only have to be relatively lightweight, but that a solution was needed to accommodate the necessary building loads.”

“Our solution was an external diagrid, a naturally stable structure,” he details,” and which allowed us to transfer the forces away from the tunnels.”

This external diagrid is based on a braced tube structure, where lateral loads are resisted due to the design working as a hollow cantilever perpendicular to the ground. In effect, by using an assembly of columns and beams, a rigid frame is formed that constitutes a “dense and strong” structural wall. It is designed to be sufficiently strong to allow the interior of the building to be simply framed for gravity loads.

Lee tells me that as opposed to using a traditional core-loaded building, the design resulted in the building being “30% taller, 30% lighter, and 10% quicker to build.” He comments: “This is clearly the most important innovation, and allowed us to effectively maximise the height of the building with great potential for the architecture.”

A hybrid

The rest of the above ground structure is a hybrid steel and concrete frame, constructed in eight-storey lifts that required close tolerances. According to the architect,

this core was constructed “quite rapidly,” with the diagrid structure following close behind, providing structural stability as the tower progressed.

As the team moved up the building, they utilised a number of different types of construction to create the varying floor plates inside this structure – all catering for the differing needs of the building’s functions. On the intermediate floors between the nodes, for example, a post tension concrete solution was utilised, which allowed for thin slabs and a reduction in the amount of reinforcement necessary, and weight.

Then, at the node floors, the team used a steel beam solution with precast concrete slab units. This created a deck between the buildings, which performed as a platform from which to create the next four floors of the diagrid, and separated the work above from the construction on the intermediate floors.

“Although none of the techniques we have used are unique on their own, bringing them together made for a very innovative solution, resulting in a hybrid building that is very efficient,” says Lee.

A sculpture for the city

Just as their work on the structural solutions, HCL carefully curated the building’s aesthetics and the housing of its various functions, the former inherently dominated by the external structural design itself, as well an aim to “make a statement,” given its unprecedented nature in the area.

“We wanted to create a sculpture for the city,” says Lee. “To achieve this, we desired a tall and slender structure that has a clearly defined silhouette, alongside an elegance and grandeur befitting its place as a landmark in the capital.”

The architect says that visually, this shape had to work on many scales, with its function and identity needing to be clear at long range, while attention to detail and high quality materials were required to “provide a texture” at close range, and make it “a fine building to move around, enter, touch, and use.”

The aluminium cladding to the exterior diagrid manifests this most prominently; designed to continually catch the sunlight as it moves around the building (allowing each facet by facet to be illuminated as the sun moves). Also, on a smaller scale, it provides a subtle texture “that sometimes sparkles.”

Lee says the building’s facade design, as well as its orientation, is a “direct response” to the listed dock setting and riverside location, with a “strong axial arrangement with the water, and to the direct axis of the Canary Wharf Underground Station entrance.”

He explains further: “This orientation also reduces directly facing north or south aspects – avoiding undue solar gain or heat loss.” The building’s diamond external language also provides a relationship to the nearby rectilinear office buildings, and the angled facades give the building “elbow room, alongside glimpsed views between its neighbours,” says the architect.

‘Tripartite’ design

In order to further strengthen its recognisability and legibility from a distance, the building uses a “modern but classic tripartite design,” says Lee, with clearly defined zones of a base, a middle and a top, each reflecting their functions.

On the ground floor, the building is set back underneath the above-ground transfer structure, making for an inviting entrance. This base is three double stories high, with the ground floor occupied by a grand entranceway, lobby, waiting areas, post delivery, lift lobby, and back of house facilities. The lobby has two entrances, one at each end, with open frontage over the dock, and the desk itself continues the diamond concept on the building’s exterior, in characterful marble.

Going up, there is a public “world-class” restaurant at level one, and at level two, a varied amenity space, including a lounge, private group dining, meeting spaces, fitness areas, and internal and external children’s play areas.

In the middle is the residential accommodation, located within the diagrid part of the building and covering over 56 floors. This section houses a gross external area of 76,000 m2 of apartment space, all of which is served by four passenger lifts travelling at 6 metres a second.

Lastly, the top of the building houses a screened plant area. Among the many necessities of a building of this size and function is a tuned mass damper to reduce mechanical vibrations across the building.

Framing views of London

Discussing the interior design, the architect argues that the external architecture also “significantly benefits the internal environment” of apartments, with the diagonal columns “like sculptures, sometimes framing views.”

“The lean design brought many such benefits to the apartments,” continues Lee, listing among other elements, a reduction in the energy requirements. This meant systems required to heat and cool the apartments “are minimal.”

“The high perimeter ratio means there is lots of frontage, and the radial planning ensures the apartments open out to the light and views,” he adds.

All the apartments are generously sized to include an element of amenity space, and all have openable windows and their own ventilation system with built in heat recovery.

With only four internal columns, all being near the building’s core, the clear-span structure allowed for large open plan layouts, with generous areas of uninterrupted glazing. A further benefit introduced here, as the party walls are non structural, is that the building is open to reconfiguration any time in the future.

An amazing result

Looking back on the process that achieved all this, Lee says “it has been an amazing project to design and deliver,” and was “most grateful to everybody involved, who have given a tremendous amount of enthusiasm.”

He believes the design has achieved the practice’s key aim of making the most of the space, while creating the landmark building the Canary Wharf Group desired.

“It was important to all of us to set a high standard for this new icon, with its prominent position on the edge of the estate, and I for one think it sets a fantastic example.” He concludes: “It has not always been easy, but it’s a wonderful project.”