Cologne Oval Offices, Cologne
“A perfect office is just like the people that work inside of it: imperfect and emotive”
Matthias Sauerbruch
With the Cologne Oval Offices, Sauerbruch Hutton ArchiteKten have succeeded in creating stimulating offices in the best sense of the word. At the same time, they have designed an architectural icon that is not only uniquely distinct, but also highly efficient.
How will we work in the future? What do prestigious, efficient and exciting offices look like? And how can state of the art building technologies be intelligently and efficiently implemented while remaining user-friendly?
On Cologne’s Gustav Heinemann-Ufer, less than three kilometres from the dome, stand two buildings that answer all of these questions in an impressive manner. The “Cologne Oval Offices” (COO), as the Berlin-based Sauerbruch Hutton architects call the structures, have cleared up numerous stereotypes. These include the old, and sadly all to often true, notion that office buildings have to be rational, grey, square and above all boring.
The COO, which were constructed from 2007 to 2010 for investor MEAG, prove to be the exact opposite in almost every way. Like softly curved contours formed in the Rhine meadows by the glacial movements of the last ice age, these two structures blend into the river’s banks as though nature herself had placed them there. Their 43,000 square metres are spread over five stories as well as two staggered floors, that wind around two courtyards and thereby allow sunlight to illuminate nearly every one of the 1,600 workspaces in the building. Each building has three “cores”, each equipped with its own elevator, stairway and infrastructure, which makes a highly flexible distribution of the office space possible. The most noticeable characteristic of the Cologne Oval Offices though are their colourful façade elements - a Sauerbruch Hutton trademark which has already appeared in such designs as the Museum Brandhorst in Munich, the GSW building in Berlin and the Dessau Environmental Agency. “Our interest in colour came during our studies and was partially borne out of the necessity of achieving high-impact architectural effects on small budgets,” says Matthias Sauerbruch. Colour, adds his partner Louisa Hutton, provides spaces with an emotional dimension. “People react instantly and emotionally to colour. When a building is colourful, people develop an almost direct relationship to it - which is something that cannot be said of every architectural device.”
The architects used seven red and seven green tones to cover the 2,500 full-length windows which account for about 60 percent of the north side’s façade surface and less than 50 percent of the sunny south side. The shutters are controlled by a sunlight monitor on the green COO roof. From its vantage point, it can see well beyond the Rhine up to the Siebengebirge and the Bergische Land, ensuring the optimal amount of sunlight and warmth for the COO. Depending on the angle of the sun and how the shutters are positioned, the COO’s colourful glass shutters can give the buildings a completely different look and feel. “Together with the building’s insulation, the shades ensure low cooling and heating requirements,” says Wilhelm Herkersdorf of ZWP Ingenieur AG, the company responsible for the building’s technology. “Because we were able to keep the base load so low, we can cover the residual demand mainly with sustainable resources.”
These sustainable resources can be found in a basement room in the COO, where the energy engineer stands between a tangle of large pipes emitting a soft rustling noise. This rustling is caused by the flow of 13 to 16 degree Celsius groundwater that is being pumped from 32 metres down. It passes through a cold exchanger, then flows through thin pipes in the ceiling of the Cologne Oval Offices before draining into an old rain water canal that flows back into the Rhine. During the summer months, the groundwater serves as a natural coolant, while the offices are heated with district heating during the winter. The heat exhaust from printers, computers and users is captured (up to 80 percent) by the heat recovery system installed in the ventilation system. There it is mixed with fresh air and fed back into the offices – a holistic approach that was rewarded with the European Union’s “Green Building” certificate. With just 105 kilowatt hours per square metre per year, the primary energy consumption of the Cologne Oval Offices amounts to about half of a similar office building. This results in the reduction of the so-called “second rent” in addition to lowered energy consumption and CO2 emissions. While normal offices with air conditioning systems cost about five to six euros per square metre per month, the COO can maintain comfortable temperatures at less than three euros per square metre. But it isn’t just the occupants that benefit from energy-efficient real estate - the owners of the property also reap rewards from sustainable building structures, as a study by the RICS, a group of British real estate professionals, shows (“Sustainability and the Dynamics of Green Building”). According to the study, sustainable real estate developed more favourably in 2008/2009 and posted greater asset values than conventional properties.
The biggest accomplishment of the architects, however, is not the thoroughly planned energy concept, but rather that the design isn’t limited by this fact. The offices, with their meandering layouts, along with the shell-contoured, terrace-like stairways and colour concept that extends all the way into the depths of the underground parking, provide a warm mood for the interior. In contrast to some other energy-efficient structures that force their occupants into a corset of high tech gadgetry and user constraints, the COO provides its occupants with the greatest possible freedom.
With the custom-manufactured Berker TS Sensor, occupants can adjust room temperature, brightness and even the angle of the shutters down to the finest detail to suit with their personal tastes. And those that enjoy working with an open window on a beautiful summer’s day can do so without worry – the climate control system will automatically shut off when it senses an open window. A perfect office, explains Matthias Sauerbruch, is just like the people that work inside of it: imperfect and emotive.
Regarding the question of how we will work in the future, Sauerbruch Hutton Architekten in Cologne have provided a pleasant, optimistic answer: The best solution, as the Green Buildings on the banks of the Rhine in Cologne have shown, is working in buildings that not only have a green heart, but a human soul as well.