Concrete-and-glass composite construction was used in church building throughout the world in the 1950s and 60s. It consists of thick, intensely coloured pieces of glass (“dalles de verre”), usually 2–3.5 cm thick, cast into flat concrete panels or blocks. Though once prized as a means of overcoming the dialectic between wall and opening, this form of construction is rarely used today. Without an additional protective layer of glass, it is incompatible with modern indoor climatic standards. In many cases, too, the different expansion coefficients of concrete and glass were ignored, a fact that ultimately necessitated extensive refurbishment work. Furthermore, the outer face of the exposed concrete and the lack of figurative depictions did not always meet aesthetic requirements, and in a number of cases, the internal spaces were too dark for church use. Kai Kappel