Behind The Scenes – Q&A with Christopher Christophi, Perkins&Will, London.

Chris reveals the story behind the concept and design of 150 Holborn, Sidara’s award-winning Showcase European HQ.

Hello, Chris. Please can you explain what your role at Perkins&Will involves? 

I’ve been with Perkins&Will for around 11 years, seven of which were as Lead Designer, Architect, and Associate in Charge for 150 Holborn, for both the commercial and residential aspects of the building.

Could you talk us through your contribution to the design and delivery of 150 Holborn?

As Lead Designer I was focused on driving forward the design philosophy and overall vision from concept to building design detailing, through to construction, including stakeholder engagement. 

Perkins&Will were responsible for coordinating the wider design team including structural engineers, MEP consultants, and the interior designers for the successful delivery of the project, and bringing the vision to life.

Were there any key challenges you faced in delivering any of these aspects at 150 Holborn?

It was a unique opportunity because it allowed us really to push the limits of what a multi-tenanted office building could be. Because, you know, we’re all unique, independent businesses even though we’re all part of the parent company (Sidara).

We had to balance the need to allow all the companies to have their own identities on their floors, while still encouraging everybody to come together and feel like they’re all part of the wider Sidara Group.

So, the biggest challenge was, how do you begin to create a building that can address that tension? You’re asking everybody to come together and collaborate, but ultimately everybody still wants to be independent.

Everybody has slightly different work cultures, work styles, and different ways of engaging with clients. And as the design evolved, it was more about creating spaces where we could incidentally come together rather than forcing it.

That’s the reason the staircase spirals in the way it does and lands in different places across the floors. To allow those encounters to happen naturally. And we can all meet through the central atrium and on stairs throughout the day. You have that visual transparency vertically and also horizontally because the floors were designed to be as flexible as possible and the floor plates are open.

Another challenge was making sure, when you’re investing so much time and money on designing and installing the stairs, that people will actually use them.

We did that by stacking the building. So, we’ve got the public cafe on the ground floor and the business lounge on Level 1, both of which are outward facing. And by deliberately placing the cafe and the pavilion space on Level 7, people had to move vertically throughout the building rather than staying in one place.

Normally when you go to the office you arrive at Reception, you get the lift to your floor, and go to work until it’s time to go back home. Whereas here, you’re more inclined to move up and down the building, which encourages those incidental meetings. And that’s great for collaboration and knowledge sharing when we’re working on projects together.

It’s easier to share ideas and expertise across the Group and push designs collectively. Not necessarily to drive a specific project but for the betterment of the built environment.

And that’s been a really successful outcome.

Yes, although it’s not just about the way the space was designed, it’s also about the muted materials palette in the central atrium and the shared areas. That palette has allowed each of the businesses to express themselves the way they wanted to on their own floors. Like Currie & Brown carrying through their brand identity with the pop of red in their meeting rooms. Whereas Perkins&Will’s floor is a lot more organic with wood and planting.

As you’re making your way up the building, you can instantly see each floor is different, and it expresses what that company does and their ethos. Clients and visitors recognise that as they make their way through the building.

150 Holborn is all about collaborative working and bringing everyone together, but you’re absolutely right about each company wanting to retain their own identity as well.

It was the biggest challenge of all because, historically, each company always had their own dedicated floor with a typical office floor plate, which is private and enclosed from the rest of the building.

Whereas here we’re aiming for “my space” but also “our space,” and I think we’ve successfully met that challenge.

There was also a fear that an open atrium would come with a noise transfer, which would impact neurodiversity and inclusion as the space could become overwhelming. So, the atrium acoustics have to work exceptionally hard to create an almost library-esque environment.

Reception is a little echoey with some reverberation. But as soon as you head upstairs, the acoustics completely change because the building is working really hard to absorb sound so you don’t get that noise transfer between the floors. The acoustic perforations and micro perforations in the finishes mean you’re getting all the benefits of the shared spaces but your floor feels like a single tenanted floor.

And it’s unique because you’d normally pay a premium to have access to the terraces and atrium spaces and cafes and subsidised foods that we all enjoy here. With so many people choosing to work from home because they find an open space distracting and overwhelming, it was really important for us to get those acoustics right, and to offer them a comfortable working environment.

And somewhere they would want to come to, rather than work from home all the time. Because it is quiet when you go up the stairs, there’s none of the noise you’d normally expect to hear.

Yes, exactly. And I guess another challenge was that 150 Holborn has quite a complex form at the back and had to integrate itself into the urban context. Corner buildings are very hard to achieve and we’re facing 3 streets, with 2 primary streets, a slightly narrow Brook Street, and we’re directly outside a tube station on a prominent corner of a thriving London Midtown area.

So, how do we address those changing scales across the buildings? Because if you walk down all three of those roads, all the buildings vary in size, material style, and in historical nature as well.

At the back of 150 Holborn, we had a neighbour who had rigorously protected rights of light, so we had to slope the form of the roof to accommodate those. We had to optimise the building form to achieve what we needed, but also respond to the overall townscape and the protective measures surrounding us. And that includes St Paul’s Cathedral in the viewing corridor, so we couldn’t go any higher.

There were so many different dynamics that really formed the overall building shape, it was multifaceted. There were also constraints in terms of the materials. The planners wanted us to protect the clarity of the Prudential building next door.

We’re always asked why 150 Holborn isn’t terracotta red brick but that was down to a stakeholder engagement process we had with Camden Council, who were more conscious of the long distance view and on High Holborn.

So, when you’re walking along High Holborn from the City, Thameslink, or coming up from Covent Garden, we’re not blending with the Pru building, we’re a complete contrast. And that means the Pru building can be celebrated and stand out in the way it needs to, rather than us both becoming one completely merged red wall.

There were a lot of constraints that have really driven the form, the massing, and the need to accommodate each of the stakeholders’ needs across the Sidara Group. The building has to work very hard to achieve a lot of different things.

That’s interesting. Giovanni Gori mentioned that although the rights of light issue was a real challenge, it was also a real opportunity.

It was. The upstairs spaces are incredible because ultimately the building form could have been very, very different.

And looking at the delivered building, what would you say you’re most proud of now?

That’s really hard to say but, I think, my part in the building as a whole, and the way it works and fits into its surroundings. It’s a building that’s deeply rooted in, informed, and driven by its urban context. But then internally it’s addressing the needs of the people who occupy it. And the thing I’m most proud of is that it’s here, and I get to live and work in it every day.

Andrew Moore said the same, that people do really like coming here to work, which is an incredible kudos.

Yes, and it’s great to see the building doing what it’s meant to be doing, both externally and internally. The general public are using the café in Reception, which means our local community are engaging with the building as intended. And all our staff are using the Pavilion space for wellness and events, as well as enjoying the Roof Garden with its access to nature.

It’s also good that people aren’t too hung up on allowing the building to evolve a little. We’re seeing people move the furniture, change their spaces, and that was the intention, for an evolving building to accommodate evolving needs.

What would you say are the key lessons learned throughout the design and build process for clients and future projects?

I think it usually takes unique projects like this to open eyes to the importance of creating good enough spaces for people to want to come to work. That’s a big challenge for any client and every sector.

It’s showcasing the art of the possible, isn’t it?

It is and I think when clients can see that at 150 Holborn, it demonstrates the value this kind of design brings to projects.

It’s making it easier to have those conversations, to be able to say that sometimes it’s not always about the drive for area, it’s about a longer term investment in creating those dedicated spaces – like the atrium – in their own buildings. Because it makes people want to come to work and you get that longer term ROI because your people are healthier and happier, and that builds efficiency and profitability.

We’ve had a huge amount of interest from educational institutions who’ve had building tours. They’ve all said that they don’t have these kinds of acoustics in their spaces. And I think that’s an important takeaway, getting acoustics right in buildings again. Because it’s one of those things that ultimately impacts the way the space feels, and not only from a neurodiversity inclusion angle.

And a lot of this could presumably be retrofitted too?

Yes, and retrofitting is a huge thing. Back in the early concept design stage for 150 Holborn we’d conducted extensive feasibility studies before we decided to demolish the original structure. Because refurbishing the existing building just wasn’t possible, we wouldn’t have been able to accommodate all the client and occupant requirements.

But we worked hard to maintain as much of the materials as possible. 97% of potential waste from the demolition was reused or recycled. And the structural design was chosen for its ability to accommodate an easier retrofit in the future. Floors can be taken up, new holes and areas opened up. Whereas concrete struggles to accommodate that kind of flexibility, as well as having a lot more embodied carbon.

So, although every design component has a lifespan of around 60 years – which is unfortunately just the nature of our industry – the choices we made around the structure of 150 Holborn means that in 60 years’ time there will be a huge amount of this building still here. And that’s a legacy to be very proud of.