It seems appropriate that renewable energy abounds at the House of Vestas, a 30,500-square-meter office building that is the anchor of the wind-turbine manufacturer Vestas Wind System’s campus in Aarhus, Denmark. A geothermal system snakes a total of 36 kilometers under a 10,000-square-meter triangular park—which links the new building to an existing building next door. The system is producing nearly 1,000 megawatts of power annually. A total of 850 square meters of photovoltaics is spread out between 350 square meters of solar hot-water heaters on the ground level, a separate installation on the roof of a southern office wing, and thin-film PVs in the skylight glass that tops the building’s central atrium. Missing from the renewable mix, however, is the backbone of Vestas’s business: wind.
Although the company’s previous main building in nearby Randers, Denmark, had a turbine, the zoning of the Aarhus campus prohibited one. So, to get a lesson on the power of wind, visitors now stop by a high-tech, 3D second-story multimedia room for a quick presentation.
The new structure, which is composed of six three-story office wings united by an expansive atrium and central meeting center, consolidates departments that were previously distributed between buildings in both Randers and Aarhus. The new building also creates a home base for the international company. (Hence the building’s name: House of Vestas).
From the beginning, Vestas sought a flexible, energy-efficient structure, targeting both low-energy class 1 building regulations set by the Danish government (which requires energy demands to be half of that of a standard building) and LEED Platinum certification.
To meet this goal, Vestas hired local Danish architecture firm Arkitema, which, at that time, had just finished a neighboring Vestas building that houses research and development departments. In addition to a high-performance structure, the design brief required space for 500 people with the ability to expand that in the future. (This was a lesson learned from the aforementioned R&D building, which Vestas outgrew before it was completed.) To that end, the current building has five office wings on the north side of the structure, but can support two more wings to the northeast.
Packaged within the dark exterior of slate panels and a black-tinted glass sunscreen are light-toned, airy offices currently for 450 people, 85 meeting rooms of various sizes, a professional TV studio, a 342-person auditorium, a canteen that serves meals cooked on site daily, and lockers and showers in the basement for commuters to use. Rather than lump all the components in one big block, the individual office wings—which are connected at each exterior end by floor-to-ceiling glass walkways and feed into the common atrium in the center—are structured to break up departments as needed while still providing visual connections, allow in ample daylight, and reduce the need for artificial lighting. In between each wing is a sheltered courtyard.
“The courtyards are about getting daylight in and also provide a view from each office,” says Glenn Elmbæk Olsen, senior creative leader and associate partner at Arkitema. All interior spaces are outfitted with daylight and occupancy sensors to adjust the high-efficiency lighting as needed. To help regulate daylight, each office wing is equipped with a dynamic sunscreen made up of 3-meter-by-80-centimeter panels of matte and reflective glass. The panels are arranged in a two-layer system, with the exterior level protecting the highly insulated interior layer. The system is designed for motion, with some of the panels fixed and others that move up and down individually, adjusting the shading in increments of one to three panels in response to daylight levels. The configurations of the panels vary, with fewer openings on the west façade to better regulate direct sunlight, while the façades to the north and east are more open. Arkitema worked with the project contractor Pihl, the engineer Cowi, and the subcontractor Glasbyggerne to create a 3D visualization of the site that served as a guide for the system’s programming. Since moving into the facility last November, Vestas’s facility managers have been fine-tuning the technology.
“The system has been a lesson,” says Morten Kjeldgaard, senior project manager in construction and civil engineering and plant product and technologies at Vestas, noting that the 3D model still needs tweaking. “The system should regulate itself. We’re quite sure we’re going to have it working, but we’ve had some mechanical defects,” he says.
Energy efficiency wasn’t the only focus of House of Vestas. Each of the five office wings on the north side of the structure is equipped with a green roof (for a total of 7,000 square meters) to help reduce the heat-island effect and manage stormwater on site (the long office wing on the south side houses a PV array). Collected rainfall is sent to two underground cisterns in the triangular park, and then reused for toilet flushing, irrigation, and maintenance of two ponds at the entry way. Low-flow water fixtures help reduce water use by 20 percent over a standard office building. The atrium is designed to be naturally ventilated, drawing air in on the ground level and exhausting it via the roof system. And its stylish design isn’t just for looks—behind the polka-dotted ash panels lining the atrium are acoustic dampers to regulate noise. In the ground-level canteen, organic kitchen waste is composted on site and then sent to a bioenergy plant for processing every two weeks. A multitude of stairways encourage walking over elevator use. (The entire building has only four elevators, which Kjeldgaard reports are rarely used.)
The company’s basement-level locker rooms encourage cycling (as do Aarhus’s extensive bicycle paths) and feature a special room with additional ventilation to help dry out damp clothing in time for the commute home. Priority parking is offered to employees who carpool, and Vestas has several electric cars for employee use, as well as additional charging stations. A public bus line is a five-minute walk away. In all, the building’s carbon dioxide emissions are 90 percent less than those of a standard office building.
Vestas is finalizing LEED certification paperwork, and an independent company is commissioning the building. “A lot of things are adjusted [during commissioning] … such as ventilation, water pumps, electricity use,” Kjeldgaard says. “We don’t yet have a year of production data. We’ve faced some issues with the heating system, but need at least one year to see how it copes. But everything we see is that it’s going to work as it’s designed. Now it’s just gathering proof.”