The DHV main office in Amersfoort was designed in the ‘70s by DHV and architect David Zuiderhoek. The basis for the design was to realise communication between engineers from various disciplines and work activities, within a green and healthy environment. The large open office spaces around the attractive atrium, which have many green features, are still used today.This indicates that the current main office is one of the most accomplished representations of structuralism found in Dutch architecture. DHV’s renovation of the 40-year-old building helps the company to once again shape its (sustainability) ambitions. Sustainability measures were evaluated for energy performance and CO2 reduction by a multi-disciplinary design team. On the basis of effectiveness and costs, a number of measures were integrated into the design. The facades are made entirely from glass and feature sun-regulated light protection, whereby more daylight enters the workplaces. The building’s energy performance has been improved from EPA label G to EPA label A, which has helped to achieve new-build status. The characteristic open structure inside the building has been retained. This has been made possible by the innovative use of fire compartmentalisation (fog screens). Finally, a decision was made to modify the immediate landscape around the building, in order to improve the feeling of "working in the midst of nature".