The aim of the IEA Solar Heating and Cooling Programme Daylight for the 21st Century research was to address daylight in buildings issues that had arisen in the 1990s particularly the need to integrate human response with the application of daylighting systems. Daylight systems are defined to include the associated shading and electric light control strategies. The research focused on non-residential buildings, such as offices and retail stores, and institutional buildings such as schools.

Two key research issues were identified:

• The determination of occupant response towards the luminous and thermal environments in buildings which use daylighting systems and daylight responsive controls.

• The integration of daylighting systems, electric lighting, and shading controls in order to optimise energy savings while taking into account occupant response.

The research planned a number of Outcomes

• Generic descriptions of daylighting requirements for inclusion in
  codes.
• Technology roadmaps for designers with performance targets.
• Guidelines for control system interface design to account for user
  reaction.
• User friendly computer tool releases with working documents on plug-in
  specifications for sky models and fenestration systems.
• Guidelines on appropriate use of tools.
• Demonstration of solutions which are adapted to commercial and institutional
  buildings.
• The transference of practical results to architects, engineers and
  industry by means of workshops and by regional support groups and an
  international web site to include data sets of user preferences, building
  performance targets and case studies of noteworthy buildings.