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Task 21



Title: Daylight in Buildings
Task Concept paper accepted: October 1993
Project definition phase: March 1994 – May 1995
Commencement date: September 1995
Completion date: December 1999


Although it is always difficult to establish facts of what was the cause and what the impact, a significant change in building design practice has occurred over the 4-6 years duration of the Task. The single most important result of this great international effort is that architects and engineers have become much more aware of the importance of daylight for good and sustainable building design.

The specific accomplishments of Task 21 should be seen as important supportive elements for the development of a building design practice in the IEA community towards the situation where daylight and luminance distribution in space and building is addressed from the beginning till the end of the design process. Among these important elements are:

  • Established international procedures for evaluation of the performance of conventional design solutions and innovative daylighting systems as well as performance of daylight responsive lighting control systems
  • A comprehensive source book on daylighting systems and components giving an overview of the main technologies for enhancing penetration or improving distribution of daylight in working spaces
  • A broad survey of actual design solutions in selected buildings throughout the IEA community
  • A comprehensive guide for application of daylight responsive lighting control systems documenting the monitored performance of available systems
  • A series of user-friendly daylighting design tools, from simple tools to be used at the early design stage to advanced tools to be used when detailed design decisions are made at the end of the process
  • Established international procedures and protocols for monitoring the daylighting performance of real buildings including the assessment of users’ opinion of their working environment
  • Documentation of the results of a comprehensive monitoring program for evaluation of the energy and daylighting performance of 15 selected Case Study buildings


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