THE OWNER CHARLIE GREEN OF THE OFFICE GROUP
When we started The Office Group (TOG) 20 years ago we wanted to distinguish ourselves in the office rental sector and decided the way to do it was through better design. That’s been our north star. We wanted to create buildings that people want to be in and that we could legitimately stand behind.
For us environmental performance is also absolutely central to better design. We now have a portfolio of 72 properties, covering 3.1 million ft2, and until the Black & White Building all of them have been existing buildings which we’ve refurbished, in itself an environmentally sound thing to do. But, an essential part of refurbishment has also been to further minimise our buildings’ environmental impact. For instance, at one of our properties, 81 Rivington Street, opposite the Black & White Building site, we planted an intensive green roof and installed storm water run-off and grey water recycling systems. We also used a lot of recycled material.
And not only is this the right thing for the planet, it’s right for the business. It’s good for TOG when we can show prospective occupants solar panels and green roofs and talk to these sorts of initiative.
The Black & White Building is our first purpose-built property and we did have planning permission for a glass and steel design. But it wasn’t right for the site. Then I met Andrew Waugh of the Black & White Building’s architects Waugh Thistleton. It was at an event on sustainability. I was talking about our approach to it, he was talking on timber building and we got chatting. He invited me to go to furniture maker Vitsoe’s hybrid timber warehouse in Northampton. Walking into that building was such a different experience, with its bold use of engineered timber, including beautiful slender beech BauBuche beams and columns. It really brought home to me that what you put into a building determines your experience of it. Moreover, Vitsoe rent out part of the space and the occupants were a local ballet company. So you had this beautiful structure, people all around packaging goods and classical music. I was in already, but that really sold it!
So we decided on timber for the Black & White Building. Perhaps it was a bold move for our first purpose-built property. But we wanted to push boundaries. We wanted to be different and to make statements about what we believe in and feel is needed in the real estate industry. We wanted to create a building that would challenge the norm and demonstrate that you can build better.
We decided with Waugh Thistleton that there would be no tokenism in construction. Besides the BauBuche beams and columns, CLT panels, the glulam-framed façade and the sustainable US tulipwood louvres, we have end grain oak flooring, ash furniture, cork wall coverings in the lift and totem sculptures made from beams recovered from the warehouse that was previously on the site. Even the lift core is CLT. We wanted to maximise the biophilic benefits and achieve an invasion of the senses with all these natural low carbon materials.
The structural frame was erected by a team of six in just 14 weeks and compared with a steel and concrete building site, it was clean, with fewer material deliveries – and it was quiet. We mounted a decibel meter on the side of the building and promised to compensate our neighbour, a recording studio, if noise exceeded a specified level. It never did.
The finished building has more than exceeded expectations. When you walk in it makes such an impression. It’s got a warmth and intimacy emanating from all the exposed timber. It shows that with design and care you can create something really human – and people experience it without even realising it’s the building influencing the way they feel. It’s also acoustically highly efficient. And then there’s the smell of the wood, which actually changes with the seasons. It’s an extraordinary achievement.
The initial cost was about 15-17% above conventional build. But this has been partly defrayed through programme savings and rapid occupancy. This building just appeals to people and it can benefit their businesses as it speaks to their brand and their ethos if they can say to clients ‘we’re in the City of London’s tallest timber building’ that represents a 37% embodied carbon saving on a steel and concrete equivalent. So we’ve shown you can create a building that’s sustainable, beautiful and commercial. We’d budgeted for full occupancy in 12 months. But we were at 55% after six weeks!
THE ARCHITECT DAVE LOMAX OF WAUGH THISTLETON ARCHITECTS
The Office Group was very clear that timber construction was the way they could deliver best in class sustainable workspace for clients. However, like most people procuring a timber building, there were questions to answer. This is Waugh Thistleton’s 28th mass timber building, so a large part of the Black & White Building journey was illustrating solutions from previous projects. Sometimes, if a client has a question about, say, noise or vibration, the best thing to do is go to a building you know well, jump up and down in it and turn up the stereo. That’s exactly what we did together.
Ten years ago when I started working with Andrew Waugh and Anthony Thistleton, we were pushing clients to adopt timber when, really, there was nothing else to compel them to do so. I’m delighted to report that now, nine times out of 10 when the phone rings it’s someone who already sees the benefit of this approach and is simply asking for our help to make it happen. But they also need to convince their board, lenders, their insurers and a great many other gatekeepers. Even there though we’re seeing change, with major funds identifying the threat to their business of holding assets that may not meet coming ESG reporting requirements, or might be subject to carbon taxes in the future. So sometimes it’s now gatekeepers opening the gate and pushing unconvinced developers through!
On the relative cost of building in wood versus other materials, a challenge in designing buildings is that you never build the same one at the same time in two different ways, so we can never know. However, WTA can say after 20 years of having this conversation with developers that there’s rarely a ‘free pass’ for doing something above and beyond statutory requirements. So we have to get every project down to a budget. The Black and White Building was no different.
On this building there are some specifics – for example upgrading the structure from glulam to more expensive BauBuche LVL – that came with a capital cost. But the reduced beam depth and footprint of columns this allowed came with trade-offs like a lower building height (so less cost in cladding) and increased lettable area. We also explain to our clients that foundations get smaller with lighter timber construction and programmes get around 20% faster – and if you’ve borrowed to build then a 20% shorter programme is real money in hand.
We think the well-being benefits are also a really important part of the timber building story, and yes, creating a high quality, appealing and biophilic environment was also important to TOG.
For the wider construction world, it is absolutely correct that we should be doing more with less, including timber. But when we design with timber we often have to compete on cost with materials that are more cheaply available. This forces us to design in ways that do not encourage structural gymnastics or costly transfer structure. It has directed us to understand the most efficient way to engineer a column grid to make optimum use of a material’s strength before weight adds a burden. The interesting thing is all these efficiencies could equally be applied to concrete and steel structures, but typically are not. This is due to the perceived cheapness and expendability of the materials and ‘this is how we always do it’. And if we’re talking about running out of raw materials, let’s focus first on the ones we cannot regrow, like sand used in concrete.
WTA is not attached to a specific product, aesthetic or even material. What we are interested in is sustainable design that can attain the highest quality outcome whilst living within our means in terms of carbon.
On use of hardwood, we’d never specify one that is endangered or clearly unsustainably forested. But when it came to using US tulipwood for the Black and White Building’s solar control louvres our collaborators at the American Hardwood Export Council (AHEC) explained that it’s in oversupply; growing faster than it can be harvested. So here we have a hardwood which is sustainable and suited to external applications. We should consider the best solution for every use case. In this scenario, with this species, for this location on the building, a hardwood is the correct solution.
The louvres cover approximately 40% of the elevation on a typical floor and AHEC says this is the largest installation of thermally modified tulipwood as a façade anywhere. We think it can be very significant in helping define a viable new use case and WTA has a number of live and pending projects in North America, so we’ll continue to highlight the potential of the material.
Our overall aim in timber construction is to achieve a new normal; to get it to absolute parity [with other materials] in the decision making process for designers, clients and contractors in terms of how it can be designed safely and cost effectively. From there, its ability to deliver sustainable outcomes won’t need our advocacy as the solution will be clear.
THE TULIPWOOD TECHNICAL ADVISER DAVID VENABLES OF AHEC
The construction and timber sectors should celebrate and engage with the just opened Black & White Building in Shoreditch.
The 17.8m, seven-storey structure, commissioned by work space providers TOG, lays out a roadmap for the office environment of today. In fact, architects Waugh Thistleton (WTA) say it demonstrates how all buildings of its type and scale could and should now be constructed. The focus is on combining technical performance, environmental ethos and functionality, while taking into account the changing way people are living and working and perceiving the workplace.
Well-being lies at the heart of the design. It’s about the materials used; what they are – predominantly bio-based – their aesthetic, how they’re perceived and how they make occupants feel. From the façade to the interiors, these are not just individual components of the building – they are the building. And structurally it’s an entirely wood solution.
The key structural elements, all supplied by James Latham, comprise the Züblin-made CLT core, floor and wall panels, plus the glulam frame for the façades. These tie into beech BauBuche LVL beams and columns from Pollmeier. This is a phenomenally strong engineered product. It makes less timber do more, enabling the architects to design a refined, elegantly slender framework.
An eye-catching feature externally – and key contributor to the building’s energy performance – are the brise soleil fins in thermally-modified American tulipwood. Supplied, via Morgan Timber, by Northland Forest Products, these are individually shaped using parametric modelling and are vertically or horizontally mounted according to the angle at which the sun strikes the building through the day. So they help maximise the building’s use of natural light, but break it up and control energy gain, minimising the need for non-recyclable solar control coating on windows.
AHEC worked with WTA in a technical advisory role on the specification of tulipwood. It was chosen due to its technical performance and sustainability, with the species comprising 7% of the overall US hardwood forest. It has not been widely used thermo-treated, but where it has, such as in the Maggie’s Centre in Oldham and playground structures at Chisenhale school in London, it’s been shown to be durable, strong and stable in exterior use. Our tests also showed it takes fire retardant treatment well. Moreover, it ages in a pleasing, gentle way – and we’ll be back to record the process as a reference for other projects. It’s been tremendously exciting to be involved with the Black & White Building. It’s underlined the range of solutions timber products can offer and how they can all work collectively and effectively together. It’s also emphasised the importance of teamwork in such a project.
It was driven by an architect with a vision for timber to deliver a building that satisfies the regulations, looks good and performs, but everyone involved was also determined to make it work.
The end result is a structure comprising 1,330m3 of timber – including two container loads of tulipwood – that stores 1,014.7 tonnes of C02 and delivers a carbon emission saving over an equivalent concrete build of 37%. It also works for the client – significantly it’s TOG’s first purpose-built office project – and it should be taken on board by planners as the way to build a successful, sustainable, safe workspace.
