The quality of life and attractiveness of cities depend, in large part, on the mix of uses and activities a neighbourhood can offer. The separation and segregation of functions, which characterized urban planning and architecture in the past century, are today inadequate for contemporary lifestyle and inefficient to face the new sustainable challenges: land shortage and its higher prices; the need to reduce buildings life cycle energy demand and the greenhouse gas emissions; the demands of new building typologies to meet the changes in society, work and leisure. The aim of the research project is to investigate the sustainable potentials of mixed-use buildings. The paper presents in particular the benefits for circular economy coming from the pooling of spaces and energy in one single structure with different uses. Building programs of the following SIA (Swiss society of Engineers and Architects) categories have been taken into account: Industry and Crafts, Trade and Administration, Culture and Social Life, Leisure Sport Relaxation, Hotel and Tourism, Housing, Education Training and Research. Representative building programs were established on the analysis of about eighty architectural competition programs held over the last ten years in the Cantons of Geneva and Zurich. The review shows how in the French speaking area the practice of mix-used building is less widespread than in the German-speaking area (only 50% of the analysed competition programs gather together two or more uses against the 70% of the Canton of Zurich). To evaluate the potential of building programs interconnection, two series of matrixes have been developed: a series of monodisciplinary matrix on architecture, structure and energy, and a series of multidisciplinary matrix. This paper focus on the architectural and energy monodisciplinary series. Each matrix has twenty-five rows and columns representing a room/space typical of the analysed architectural programs. The different degrees of pooling of rooms and building programs are presented and in particular their aggregation with those of the energy matrix for the following criteria/parameters: 1. space heating demand smoothing; 2. space cooling energy demand smoothing; 3. space ventilation energy demand smoothing; 4. thermal waste (spaces for which energy services produce thermal waste); 5. thermal cascade (spaces with decreasing or increasing heating or cooling temperature levels); 6. thermal zoning (spaces with similar temperature levels). Sustainable combinations of programs open to new possibilities in the field of building typology. Results show that the mix of uses and an interdisciplinary approach in architectural programming at an early stage of the design process contribute to reduce the carbon footprint of the building, provide environmental benefits and generate at the same time long term savings cutting down construction and operating costs.