The Centre for Free-Electron Laser Science (CFEL) is a joint initiative of DESY, the Max Planck Society and the University of Hamburg. The building has 24 laser measuring rooms and as such the design needed to take the special demands on the structural dynamics associated with the use of advanced lasers.The layouts of the offices and laboratories were carefully considered to encourage an atmosphere of communication and collaboration. Texlon® ETFE skylights with a “filigree” steel supporting structure consisting of tubular steel profiles to cover the complex geometry of the central high foyer.The Texlon® ETFE foils were printed with speciality lacquers to allow high levels of light transmission into the building while simultaneously reducing solar gain – to ensure optimal ambient temperatures for the building occupants to feel as if they are outside all year round – but at the same time they are protected from the elements in the colder seasons.The lightweight Texlon® ETFE system offers tremendous advantages over traditional roofing systems in terms of energy savings, sound dispersion, lower structural costs and better light transmission.