Task to Promote Daylight-Conscious Design

Artificial lighting represents a large part of the energy consumption in non-residential buildings, but daylight-conscious architectural solutions can allow a considerable part of this electricity consumption to be replaced by natural light. At the same time, cooling loads generated by heavy use of electric lights are often reduced. In addition, it is generally recognized that effective design of fenestration systems and the proper use of daylight in building interiors contribute to the occupants' well-being, satisfaction and productivity.

However, there are a number of barriers that hinder appropriate integration of daylighting in building design. One is lack of documented, empirical evidence that daylighting can substantially improve energy efficiency and visual quality in buildings. Furthermore, there is insufficient knowledge and a lack of information on new fenestration technologies and lighting control systems and the ability of such systems to enhance utilization of daylight. Finally, there is a lack of user-friendly daylighting design tools.

These problems will be addressed by Task 21, "Daylight in Buildings," which has received a "green light" from the Executive Committee. To advance daylighting technologies, testing and evaluation of systems will be carried out in laboratory tests emphasizing visual performance, energy savings and user acceptability. Monitoring of daylighting systems in 8-10 new buildings will also be performed to provide cases studies which can be used to promote daylight-conscious design. Work will also be carried out on daylighting design tools, building on the work done in Tasks 11 and 12.

The main deliverables will be:

• A system-specific design guide on daylighting systems and control systems providing recommendations on systems integration and data on energy savings potential.
• A set of daylighting design tools that improve the designer's ability to predict the performance of daylighting systems and control strategies and to evaluate the impact of daylight integration in the overall design concept.
• A case studies report with measured data on the performance of a variety of daylighting systems, their energy savings, and user appraisal of the environmental conditions.

The target audience for the system design guide and the design tools are primarily design practitioners, engineers, and architects, and product manufacturers. The target audience for the case studies are primarily architects and building owners, i.e., the key decision makers at the early stage of building design.

Task 21 will be led by Kjeld Johnsen of the Danish Building Research Institute, on behalf of the Danish Energy Agency. There will be close coordination with the IEA Energy Conservation in Buildings and Community Systems Program.