Glassworks: The History of Glass and its Architectural Identity
The technical specifications can, however, determine the amount of light that is allowed to transmit through the glass faade. The technology to determine and control the selective transmittance has proved to be one of the most difficult tasks in the glazing industry. One of the main difficulties is the relationship between light transmittance and thermal characteristics. The more light transmittance the glass pane allows, the more thermal transfer it permits. Daylight performance in any urban context depends on a combination of direct sunlight, diffused skylight and the reflection of light from the faades and the ground. Glass faades influence many of these variables. This might explain the visual dominance of glass faades in many urban contexts. Daylight literatures have identified a number of technical variables that are related to the characteristics of space configuration that impact on the daylight performance. The transmittance of the reflected daylight differs from that of direct or diffused sunlight.