Active Glass Walls: A Typological and Historical Account

This paper provides a summary analysis of the typological and historical development of active glass walls. From the beginning of the glass revolution, the fascination with large areas of transparency has been tempered by the negative environmental effects they can produce: excessive heat loss when it is cold, excessive heat gain when the sun shines, and even excessive daylighting. These problems were already recognized by the glazing pioneers of the nineteenth century, and it was apparently Jean-Baptiste Jobard in 1849 who first imagined that the air between the layers of glass could itself be heated or cooled and so modify the effects of large glass walls. In 1914, Paul Scheerbart, the visionary author of Glasarchitektur, cautioned against that practice, arguing that “convectors and radiant heaters should not be put between the two skins [of glass] because too much of their output will lost to the outside air, ” and so began nearly a hundred years of experimentation and dispute about heating, cooling, or moving the air in glass walls.1 The technique was picked up a few years after Scheerbart by Le Corbusier, who called it a “neutral wall”, and then by many others in the decades after the second world war as glass curtain walls became a normative form of construction. In recent decades, the numbers and variety of active glass walls have exploded, initially in northern Europe, but increasingly in Asia and the Americas as well. Some of the more common terms of designation are “double glass facades, ” “climate walls, ” “air-extract windows, ” intelligent facades, ” and “multiple skin facades, ” and while there are some distinct classes of these walls, the proliferation of types and of categorizations can make the field difficult t