The present research investigates an innovative use of fibre-reinforced composite materials (FRP) in the building industry and develops a construction system that has the potential to fuse structural, energy and architectural performances in one single shell, which is light, load bearing and efficient, with systems integrated inside it. This gives the opportunity to deal with the concept of sustainability in a broader sense, changing the approach from assessment protocols based on checklists to the idea of integration and inter-dependence of different aspects. The aforementioned concepts are applied to the design of a University students’ pavilion: its energy and daylight performances are analysed through simulations, while a 1:2 scale prototype of a pavilion portion has been fabricated to test the material characteristics. The construction system consists of a double curvature, load bearing, sandwich shell composed of two external FRP layers and a polyurethane core where systems are included. Potentialities and limitations connected to these materials are discussed, including a critical discussion of the building construction, transportation, energy consumption, environmental impact and overall efficiency and cost. The pavilion design aims to maximize daylight autonomy and solar gains in winter, while avoiding glare and minimizing cooling loads in summer. A ventilation system capable of refrigerating during the night is developed in parallel to a VRF system with heat pump, which is completely autonomous from the existing building. Operative temperature and comfort are evaluated for different periods of the year and results are displayed on maps. Software integration is a key factor in this process of extreme integration of different functions: opportunities and limitations related to the use of software are also discussed.