Red Oak delivers warmth, wellbeing and the wow factor
A major and ultra-prestigious application in the City of London could really put U.S. red oak on the European map.
The European market has been something of a frustration for U.S. red oak suppliers. The species is Americaโs most prolific hardwood, so, in those terms, its most sustainable. In the U.S. itself itโs used extensively in a huge range of construction, interiors and manufacturing applications, while other markets, such as China and Japan, also canโt get enough. But in Europe red oak has lagged some way behind its ubiquitous U.S. white cousin in popularity.
The market breakthrough itโs needed, say admirers, has been a major showcase project to demonstrate its aesthetic and performance appeal.ย Well now it has one โ and wow. They donโt come much more major or more showcase than the just opened 1.1 million ftยฒ European headquarters of global financial data, software and media colossus Bloomberg.
Designed by a Foster + Partners team, led by Norman Foster himself, the stunning City of London building, is already being lined up for architectural awards. Itโs also scored on the environmental front, achieving a record BREEAM rating for an office development of 98.5%.
Making the building more significant for red oak still, project architect Michael Jones said the timber is not used in any token, decorative way. Itโs core to the interior aesthetics and to delivering on the designersโ wellbeing and environmental goals. Itโs also used in considerable quantities โ 37,160 mยฒ for the floor alone.
To answer the question why wood in the first place, and so much of it, Mr. Jones tracks back to initial conversations with Bloomberg CEO Michael Bloomberg.
โPreviously the company has occupied existing commercial space, but establishing their European headquarters, they felt, deserved something bespoke and tailored to the way they operate,โ he said. โAs well as expressing this through the architecture itself and while wanting the building to be very much of its own time, they also wanted it to be very contextual and historically rooted in its place through the palette of materials. Hence the extensive use of bronze and Derbyshire stone โ 9,000 tonnes of it โ but equally timber, all of which you see quite typically around London. The task was to take these materials and use them in a fresh, innovative way.โ
Sustainability also led Foster to timber. โBy this we mean not only that timber is renewable, energy efficient, carbon rich and all those other good things, but that it helps achieve sustainability in the broadest sense,โ said Jones. โThe sustainability of a building is also about the wellbeing of people โ and people feel better in a place featuring natural materials.โ
While some discount red oak because of its pinkish hue it was this, combined with its technical properties, that actually helped decide its choice for Bloomberg and Foster. โWe wanted a species with warmth that would mellow and mature with age,โ said Mr. Jones.
Architects and client did consider other species, but cherry was discounted due to its tendency, in certain circumstances, towards significantly darkening on exposure to light. It was also felt the white oaks of Europe and the USA would produce a finish that was too light in colour, with a more โyellowy hueโ. The fact that the U.S. produces red oak in such volumes also played in its favour.
โAlthough there were still times I was nervous about whether weโd get the amount we needed in the time allowed, and with the homogeneity of grain and colour required,โ said Mr. Jones. โWe were asking an awful lot of the U.S. timber industry, but they rose to the occasion.โ
The significance of red oak to the interior aesthetic is obvious from the moment you enter the lobby. In fact it helps make the buildingโs dramatic opening statement. Called the Vortex, this dramatic swirling space features 1,858 mยฒ of red oak cladding on its intersecting arching walls.
โThe Vortex is a literal and metaphorical modern twist on the timber-lined entrance hall you find in so many classical English buildings, particularly in London,โ said Mr. Jones.
This application is also one example in the building, as he describes it, where innovation has overcome the potential challenges of using wood. โHaving this much vertical cladding risked reverberation, so the timber was micro-perforated by laser. This makes it absorbent of sound, while the aesthetic is unaffected as the holes are so small. You canโt see them until youโre about 20mm from the surface,โ he said.
Red oak also features prominently in the multi-purpose room, a flexible space for meetings and presentations adjacent to the buildingโs auditorium. Here it is used in the form of glulam, a total of 1350 mยณ, comprising the โfin wallsโ which define the space.
The daring decision also to use timber for the flooring came out of a New York meeting between Michael Bloomberg and Mr. Jones and posed perhaps the biggest technical test.
โWe were talking about possible flooring types and he just asked, why canโt we use wood?โ said the latter. โThe key reasons you donโt often see it in offices is footfall noise โ and there is capacity for just shy of 7,000 people in the Bloomberg building โ and the need to access the services beneath. We wanted the aesthetic of a seamless, monolithic surface, but using conventional tongue and groove boards would cause huge problems getting to all the communication cabling and other systems.โ
Once more innovation overcame technical and functional hurdles. Teaming up with contractor and building systems and materials provider Kingspan, Bloomberg devised a solution where individual boards could be lifted and refitted at will.
โEach board has a magnetic strip running its length, which sticks it to the metal access floor below,โ said Jones. โSo you can sucker one up, lever up the surrounding boards then just drop them back into place.โ This approach also means zero creaking, while the sound of footsteps is deadened by an additional acoustic layer between board and access floor. Itโs also straightforward to replace any areas that suffer damage.
So convinced were Kingspan by the flooring solution, theyโve now brought it to market, and itโs already been used in a number of other projects. Using red oak in these various applications was also a logistical exercise.
Over and above sourcing it โ and it all had to be FSC verified sustainable or equivalent โ and shipping it over the Atlantic, the Vortex panelling was laser perforated in Switzerland, the multi-purpose room glulam walls made in Germany and the flooring machined in Italy.
The timber will need maintaining, but this should be minimal thanks to the combination of oil finish on the floor, lacquer on paneling and the materialโs inherent natural durability. And if added testimony to the latter were needed, it is also housed in the new building. Itโs constructed on the site of the Roman temple of Mithras and fresh remains, including structural timber elements, were uncovered during foundation excavations. Among other discoveries were 400 timber writing tablets and some of these and other artefacts are now on public display in what Bloomberg describes as a โfree new cultural destinationโ, the London Mithraeum, deep in their buildingโs basement.
As to whether the project will inspire Foster to use red oak again, Mr. Jonesโ response is why not? โWe used to be best known for our use of steel and glass, but the commercial market is changing and weโre using more timber generally,โ he said. โBusinesses now want their buildings to have a different sense of personality and be more responsive to people who work in them.
Timber is rather successful in delivering both these things. People warm to it and it makes them feel better about their environment. And, while each building is the result of conversation between client and architect, for sure we may use more red oak. Bloomberg loves the result itโs delivered and so do we.โ
