Reviews the development of improved visual and thermal performance of glazing during the last 30 years. Discusses complementary glazing devices such as blind systems. Gives examples of how automatic control systems have been or might be used to optimise the visual and thermal performance with regard to the varying external climate in achieving specified building management strategies, such as energy economy. Describes and discusses variable performance and glazing products. Summarises the current situation or potential for commercial development. Discusses current developments in further improving the thermal performance of glazing materials and presents the latest advances in low-emissivity glass technology plus the potential for future applications. Concludes by describing the international project 'Fenestration 2000' and presents the findings of the first stage.

KEYWORDS: Buildings, walls, windows, glazing, controls, performance, energy management, glass, blinds, coating, aerogels, electrochromic, automatic, energy conservation, thermal insulation.