In a central location on the Delft University of Technology campus, the educational building ECHO was proposed in 2017. The construction is designed to offer maximum flexibility. A superstructure is placed on 8 fixed “table legs” serving as cores, containing lifts, stairwells, shafts, toilets and other technical areas. The amphitheatre and large lecture rooms are separate from the primary supporting structure, ensuring the entire building can be delivered column-free and is highly flexible in terms of its layout and for future adaptations in education. For the façade a vertical modular sawtooth profile has been chosen, closed on one side and transparent on the other. The closed side makes it possible to connect flexible walls to the façade in the future. The sun-oriented roof also consists of a sawtooth profile, incorporating PV panels, which continue onto the façade. Echo has a powerful all-round appearance. The central atrium creates a fluid connection between inside and outside: a real Living Campus! A healthy and pleasant interior climate forms the basis for a good working and learning environment. This is based on individual controllability, good ventilation, acoustic absorption and pleasant light levels. Echo gets pleasant daylight entry through the use of north-oriented shed roofs, high vertical glass sections in the sawtooth facade and a recessed transparent plinth at ground level. A large void in the middle of ECHO ensures that daylight penetrates deep into the building. High sustainability ambitions in this assignment require an integrated approach and ECHO should become truly energy neutral, a challenging task that we have tackled with a strategy based on the motto: “calculate first, then draw”. We have chosen to make a compact building with a relatively limited glass percentage across all floors. Smart building technologies have been implemented in ECHO with a “sensory network” throughout the building, which tracks data about the indoor climate, occupancy and visitor flows over time. Via Analytics, data can be processed into valuable information about the operation costs of the building. Via the façade, ECHO functions as a kind of wind-driven cooler in the intermediate and winter season and as a heat harvester in the summer. By applying low glass percentages and a minimal investment in PV panels, we keep the environmental impact low. The loose and permanent design can look at the use of circular materials and products, in order to respond to flexibility in use, adaptations to the changing future and sustainability.