GSA
Courtroom Lighting Criteria Evaluation
Task 1 Report
4
Current Design Guidelines
4.1
U.. o rs D sg Gud
S C u t' e in ie
For reference in the survey information reported below, the following are key components
of the Design Guide related to lighting:
Recommended illuminance levels are 40 to 75 footcandles, given as a range, for all
areas of the courtroom interior, except for spectator areas.
Fluorescent lighting is allowed in indirect or direct applications.
Incandescent lighting is allowed in direct applications.
Metal halide lighting is allowed in indirect applications.
Vertical footcandle level and flexibility for video and evidence display are emphasized,
as well as good color rendering.
A dimming control system is required for flexibility, allowing the judge to vary the
intensity and type of lighting.
Refer to the table in section 4.3 in i tgteD s nG i slmi ne
d ai h ei u e i n c
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recommendations for individual courtroom areas.
4.2
IESNA Lighting Handbook Guidelines (9th Edition)
Also applicable to our study are the guidelines of the Lighting Handbook (9th Edition) of the
Illuminating Engineering Society of North America (IESNA). This comprehensive
handbook serves as a standard reference and design guide for lighting in all types of
interior and exterior spaces and is used by many lighting designers to help guide their
designs.
The handbook indicates target illuminances for several task areas in a courtroom, which
are listed in section 4.3.
The IESNA handbook also indicates important factors relating to the design of lighting in
courtrooms.
Modeling of faces and objects: this refers to the amount of definition a lighting scheme
produces on a face, cause by shadows of the facial features. This is related to the
ratio of horizontal to vertical illuminance on a subject.
Appearance of the space and luminaires.
Color appearance and contrast.
Daylight integration and control.
Direct glare.
Source-task-eye geometry: this refers to the location of light sources with respect to
surfaces and tasks, which sometimes can cause reflected glare.
System control and flexibility.
Lighting for video.
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Issue March 1, 2006
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