Appendix: Light

 

L01.1 – Ensure indoor light exposure
Daylight in all spaces:
Projects meet at least one of the following requirements:

1. Spatial Daylight Autonomy of sDA200,40% is achieved for at least 30% of regularly occupied space.
2. 30% of all workstations are within 20 ft of transparent envelope glazing. Visible light transmittance (VLT) of transparent glazing is greater than 40%.
3. Transparent envelope glazing area is no less than 7% of the floor area for each floor level. VLT of envelope glazing is greater than 40%.

Daylight in common spaces:
Regular building occupants have unrestricted access to indoor common spaces with unassigned seating that accommodates at least 15% of regular building occupants at any given time. The spaces are located within the project boundary and each meet at least one of the following requirements:

1. Spatial Daylight Autonomy of sDA300,50% is achieved for at least 70% of the space.
2. 70% of all seating in the space is within 16 ft of transparent envelope glazing with views to the exterior. Visible light Transmittance (VLT) of envelope glazing is greater than 40%.
3. Transparent envelope glazing area is no less than 10% of gross internal floor area of the space. Visible Light Transmittance (VLT) of envelope glazing is greater than 40%.

 

L01.2 – Promote lighting education
Projects provide educational resources on circadian rhythm, sleep hygiene, age-related increases in light requirements and/or importance of daylight exposure on circadian and mental health that meet at least two of the following requirements:

1. Educational signage is placed at high traffic points around the space.
2. Newsletters or newsletter entries are issued to all occupants at least every quarter.
3. At least two of the resources provided for Part 2: Health and Wellness Education of Feature C01: Health and Wellness Awareness cover information on circadian rhythm, sleep hygiene, age-related increase in light requirements and/or importance of daylight exposure to circadian and mental health.

 

L02.1 – Light levels for visual activity
The following requirements are met:

1. All indoor and outdoor spaces (including transition areas) comply with illuminance recommendations specified in one of the following lighting reference guidelines:
   1. IES Lighting Handbook 10th Edition or IES Lighting Library.
   2. EN 12464-1: 2011.
   3. ISO 8995-1:2002(E) (CIE S 008/E:2001).
   4. GB50034-2013.
2. A lighting plan detials the below:
   1. Tasks or activities considered for visual lighting design in the project. All tasks and activities regularly undertaken by occupants are considered.
   2. Height of work plane or other target of illumination.
   3. Age ranges for the majority of occupants.

 

L03.1 – Lighting for hte circadian system
Electric lighting is used to achieve light levels shown in the table below as measured on the vertical plane at eye level of the occupant. The light levels are achieved at least between the hours of 9 a.m. and 1 p.m. and may be lowered after 8 p.m. at night:

1. The project meets the following requirements in regularly occupied spaces:

Option 1		Option 2	Points
At least 150 EML [136 melanopic equivalent daylight D65]	OR	The project achieves at least 120 EML [109 melanopic equivalent daylight D65] with electric light and at least 2 points in Feature L05: Enhanced Daylight Access.	1
At least 240 EML [218 melanopic equivalent daylight D65]	OR	The project achieves at least 180 EML [163 melanopic equivalent daylight D65] with electric light and at least 2 points in Feature L05: Enhanced Daylight Access.	3

 

L04.1 – Control solar glare
Window shading:
The following requirements are met in regularly occupied spaces:

1. All exterior envelope glazing has shading. Atria or lobbies may be excluded.
2. The shading is controllable by the occupants or set to automatically prevent glare. If shading is controlled by occupants, all shades are raised or retracted either manually or automatically at least twice per week.

 

L04.2 – Manage glare from electric lighting
Each luminaire meets one of the following requirements for regularly occupied spaces. Wall wash fixtures and task lamps positioned as specified by manufacturer’s data, as well as decorative fixtures, may be excluded from meeting these requirements:

Luminance	Shielding angle, α (α = 90 - cutoff angle)
< 20,000 cd/m² (including reflected sources)	No shielding required
20,000 cd/m² to 50,000 cd/m²	15°
50,000 cd/m² to 500,000 cd/m²	20°
> 500,000 cd/m²	30°

1. 100% of light is emitted above the horizontal plane.
2. Unified Glare Rating (UGR) values are met as per the below conditions:
   1. Luminaires installed at a height of 16 ft or lower meet UGR of 19 or lower.
   2. Luminaires installed at a height greater than 16 ft meet UGR of 22 or lower.
3. Shielding angles are as described in the below table:
4. Fixtures have a luminance of less than 10,000 cd/m2 between 45 and 90 degrees from nadir, and/or an intensity of less than 1,000 candela between 45 and 90 degrees from nadir.

 

L05.1 – Implement enhanced daylight plan
Projects meet at least one of the following requirements on each floor:

1. 70% of all workstations are within 25 ft of transparent envelope glazing or atria. Visible light transmittance (VLT) of transparent glazing is greater than 40%.
2. Window area is no less than 10% of the floor area. Visible light transmittance (VLT) of transparent glazing is greater than 40%.

 

L05.2 – Implement enhanced daylight simulation
The following requirement is met:

1. Projects demonstrate through computer simulations that sDA 300,50% is achieved for the area on each floor as shown in the table below:

sDA 300, 500%	Points
Achieved for > 55% of regularly occupied floor area	1
Achieved for > 75% of regularly occupied floor area	2

 

L05.3 – Ensure views
Transparent envelope glazing provides access to views at least 50% of regular building occupants. Views meet at least two of the following requirements:

1. If at ground floor, distance from fenestration to roadway is at least 25 ft from the exterior of the glazing.
2. View factor of 3 or greater.
3. Views with a vertical view angle of at least 30 degrees from occupant facing forward or sideways provide a direct line of sight to the ground or sky.

 

L06.1 – Manage brightness
At least four of the following requirements are met in all regularly occupied spaces:

1. Main rooms do not exhibit 10 times greater or lesser luminance than an ancillary space. This is to avoid substantial changes in light levels as occupants move from one space to another.
2. Surfaces do not exhibit 3 times greater or lesser luminance than an adjacent surface. This is to avoid substantial changes in light levels as occupants look around their immediate area.
3. Surfaces do not exhibit 10 times greater or lesser luminance than another remote surface in the same room. This is to avoid substantial changes in light levels as occupants look around the room.
4. Changes in light levels to 1.5 times higher or lower than initial light levels are carried out over the span of at least 30 minutes in steps or with a smooth transition. Timing considerations in the rate of change of light levels or spectrum diminish abrupt or disruptive lighting transitions.
5. Uniformity of at least 0.4 is achieved on work planes. Exclude supplemental lighting from calculations.
6. One section of the ceiling does not exhibit 10 times greater or lesser luminance than another section of the ceiling in the same room. Distribution of light across ceilings in a given room that maintains lighting variety but avoids both dark spots and bright spots.

 

L07.1 – Ensure color rendering quality
Electric lighting meets at least one of the following color rendering requirements in occupiable spaces. Decorative fixtures, emergency lights and other special-purpose lighting may be excluded from these requirements.

1. Electric lighting meets one of the following requirements:

Metric	Threshold
CRI	CRI ≥ 90
CRI, R9	CRI ≥ 80 with R9 ≥ 50
IES TM-30-18	IES Rf ≥ 78, IES Rg ≥ 100, -1% ≤ IES Rcs,h1 ≤ 15%

 

L07.2 – Manage flicker
All electric lights (except decorative lights, emergency lights and other special-purpose lighting) used in regularly occupied spaces meet at least one of the following requirements for flicker:

1. A minimum frequency of 90 Hz at all 10% light output intervals from 10% to 100% light output.
2. LED products with a “low risk” level of flicker (light modulation) of less than 5%, especially below 90 Hz operation as defined by IEEE standard 1789-2015 LED.

 

L08.1 – Enhance occupant controllability
Ambient lighting systems in regularly occupied spaces meet the following requirements:

1. Light systems are tunable and automated to meet the circadian and visual requirements of the occupants.
2. Occupants have control of light levels, color temperature and color of electric light in their immediate environment and can override automated settings for at least 30% of operating hours.

 

L08.2 – Provide supplemental lighting
The following requirements are met:

1. Supplemental light fixtures meet the following requirements:
   1. Can increase the light level on the task surface to at least twice the recommended light levels based on the reference used to meet Part 1: Light Levels for Visual Acuity in Feature L02: Visual Light Design.
   2. Are provided at no cost upon request.
2. Requests for supplemental light fixtures are met within eight weeks of request.

Return to the Main Page