The aim of this restoration project was to preserve the architectonical complex of the Glass Church of Nostra Signora della Misericordia (Our Lady of Mercy) in Baranzate, retaining the original appearance of the building while updating it and adapting it to today’s requirements and the needs of the local community. Originally designed by Angelo Mangiarotti, Bruno Morassutti and Aldo Favini and completed in 1958, the church is an outstanding example of structural engineering and Total Design with its pioneering use of a pre-stressed concrete structure and steel and glass cladding. This church was one of the first industrialized buildings in post-war Europe and has recently been declared a listed building. Since its construction it gradually fell into disrepair and was unfit for the congregation due to the unacceptable thermal conditions. The restoration work, which was completed in 2015, was undertaken by SBG Architetti, Milan, under the guidance of the original architects. Accurate research was required as, although the concrete structure remained, all of the external walls and floors had to be reconstructed and new services and a hall floor structural reinforcement needed to be added without interfering with the architectural characteristics of the building. Careful attention was paid to environmental issues and the use of energy efficient technology such as the geothermal heat pump and the quadruple-glazed window system. In order to reproduce the effect of the original facade with its plastic insulating material, new multi-layer glass panels were designed to imitate the original pattern. The iron framework of the cladding was replaced with a shot-peened stainless steel version. The community was actively involved in design and construction process leading to a sense of civic pride and social participation. Finally, after more than ten years of painstaking work, the religious community can once again use the building as intended by the original designers.