Definition of Daylight Zone

A daylight zone is a portion of a space that receives sufficient natural light to reduce the need for artificial lighting during daylight hours.

Code Requirements for Daylight Zones

The International Energy Conservation Code (IECC) and the California Building Code (CBC) require that new buildings include daylight zones in certain spaces, such as offices, classrooms, and retail stores. The specific requirements vary depending on the jurisdiction.

Separate Controls for Daylight Zones

The IECC and CBC require that daylight zones have separate controls from general lighting. This means that the lighting in the daylight zone can be turned off or dimmed when natural light is sufficient.

Code Compliant Examples

Examples of code-compliant daylight zones with separate controls include: Office with Automatic Lighting Control

The lighting in the daylight zone is controlled by a photocell or other sensor that automatically dims or turns off the lights when natural light is adequate.

Classroom with Dimmable Lighting

The lighting in the daylight zone is dimmable, allowing the teacher to manually adjust the light levels based on the amount of natural light available.

Retail Store with Occupancy Sensors

The lighting in the daylight zone is controlled by occupancy sensors, which turn off the lights when the space is unoccupied and turn them on when someone enters the space.

Benefits of Daylight Zones

Daylight zones offer several benefits, including: Energy savings

Reduced need for artificial lighting during daylight hours.

Improved occupant comfort

Natural light promotes well-being and reduces eye strain.

Increased productivity

Studies have shown that natural light can improve mood and increase cognitive function.

Reduced glare

Properly designed daylight zones can minimize glare from windows and skylights.

Considerations for Daylight Zone Design

When designing daylight zones, it is important to consider factors such as: Orientation of building

The daylight zone should be located on the side of the building that receives the most natural light.

Window size and placement

Windows should be sized and placed to maximize natural light distribution.

Shading devices

Shading devices, such as blinds or curtains, can be used to control the amount of natural light entering the space.*

Reflective surfaces: Light-colored surfaces, such as white paint or light-colored furniture, can help to reflect natural light and distribute it throughout the space. Flag for review