When you think of tax offices and student loan centres, you probably think of boxy grey buildings and gross inefficiency. UNStudio turns that notion on its head with the recently completed Education Executive Agency and Tax Offices in Groningen. Housing 2,500 workstations and room for 1,500 bicycles and 675 cars, the tower is curvaceously aerodynamic and among the most energy-efficient builds in Europe. Deliberately avoiding the intimidating, austere towers that have defined so much modern institutional architecture, UNStudio instead opted for an asymmetrical 92-metre-tall building with an organic profile calculated to appear more approachable.

The facade is girded by a series of fins that reduce the heat lost to high winds in winter, and help shade the interior in summer. Natural daylight and ventilation, adjustable at each workspace, also helps reduce energy use and provide comfort inside. Further reducing the need for artificial ventilation is a high-pressure system that takes advantage of the central engineering shafts to move large quantities of air through exterior grilles set into the 11th floor facade. Architect Ben van Berkel describes the structure as a fully integrated approach to sustainabiity: “The design contains numerous new innovations related to the reduction of materials, lower energy costs and more sustainable working environments.”

UNStudio also wanted to make the interiors more welcoming; van Berkel explains that he tried to avoid creating hallways that cut people off from the outdoors or led to dead ends. Curvy staircases and casing, and dashes of colour also add to the visual appeal inside. “We paid a great deal of attention to how people would move through the building. You can take endless walks where there is a great deal of transparency, also towards the surrounding landscape.”