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LEED v4.1
Healthcare
Indoor Environmental Quality
Daylight

LEED CREDIT

Healthcare-v4.1 EQc7: Daylight 1-2 points

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USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To connect building occupants with the outdoors, reinforce circadian rhythms, and reduce the use of electrical lighting by introducing daylight into the space.

Requirements

Provide manual or automatic (with manual override) glare-control devices for all regularly occupied spaces. For core and shell projects, glare-control devices are not required in the spaces to be fit-out by the tenant(s).

AND

Select one of the following three options.

Option 1. Simulation: Spatial Daylight Autonomy and Annual Sunlight Exposure (1–3 points, 1-2 points Healthcare)

Perform annual computer simulations for spatial daylight autonomy300/50% (sDA300/50%), and annual sunlight exposure1000,250 (ASE1000,250 ) as defined in IES LM-83-12 for each regularly occupied space. Healthcare projects must use each regularly occupied space located in the perimeter area determined under EQ Credit Quality Views. Additionally, calculate the average sDA300/50% value for the total regularly occupied floor area.

For any regularly occupied spaces with ASE1000,250 greater than 10%, identify how the space is designed to address glare.

Points are awarded according to Table 1.

Table 1. Points for Option 1
New Construction, Core and Shell, Schools, Retail, Data Centers, Warehouses and Distribution Centers, Hospitality Healthcare
The average sDA300/50% value for the regularly occupied floor area is at least 40% 1 point 1 point
The average sDA300/50% value for the regularly occupied floor area is at least 55% 2 points 2 points
The average sDA300/50% value for the regularly occupied floor area is at least 75% 3 points Exemplary performance
Each regularly occupied space achieves sDA300/50% value of at least 55% Exemplary performance or 1 additional point if 2 points achieved above. Exemplary performance

The sDA and ASE calculation grids should be no more than 2 feet (600 millimeters) square and laid out across the regularly occupied area at a work plane height of 30 inches (760 millimeters) above finished floor (unless otherwise defined). Use an hourly time-step analysis based on typical meteorological year data, or an equivalent, for the nearest available weather station. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR
Option 2. Simulation: Illuminance Calculations (1–3 points, 1-2 points Healthcare)

Perform computer simulations for illuminance at 9 a.m. and 3 p.m. on a clear-sky day at the equinox for each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Demonstrate illuminance levels are between 300 lux and 3,000 lux at both 9 a.m. and 3 p.m. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 2.

Table 2. Points for Option 2
New Construction, Core and Shell, Schools, Retail, Data Centers, Warehouses and Distribution Centers, Hospitality Healthcare
Percentage of regularly occupied floor area Points Percentage of regularly occupied floor area within perimeter area Points
55% 1 55% 1
75% 2 75% 2
90% 3 90% Exemplary performance
Calculate illuminance intensity for sun (direct component) and sky (diffuse component) for clear-sky conditions as follows:
  • Use typical meteorological year data, or an equivalent, for the nearest available weather station.
  • Select one day within 15 days of September 21 and one day within 15 days of March 21 that represent the clearest sky condition.
  • Use the average of the hourly value for the two selected days.

Exclude blinds or shades from the model. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR
Option 3. Measurement (1-3 points, 1-2 points Healthcare)

Measure illuminance in each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Achieve illuminance levels between 300 lux and 3,000 lux. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 3.

Table 3. Points for Option 3
New Construction, Core and Schools, Schools, Retail, Data Centers, Warehouses and Distribution Centers, Hospitality Healthcare
Percentage of regularly occupied floor area Points Percentage of regularly occupied floor area within perimeter area
55% at one time in the year 1 55% at one time in the year 1
75% at two times in the year 2 75% at two times in the year 2
90% at two times in the year 3 90% at two times in the year exemplary performance
With furniture, fixtures, and equipment in place, measure illuminance levels as follows:
  • Measure at appropriate work plane height during any hour between 9 a.m. and 3 p.m.
  • If pursuing one point, take one measurement in any regularly occupied month. If pursuing two points, take two measurements: one measurement in any regularly occupied month, and take a second as indicated in Table 4.
  • For spaces larger than 150 square feet (14 square meters), take measurements on a maximum 10 foot (3 meter) square grid.
  • For spaces 150 square feet (14 square meters) or smaller, take measurements on a maximum 3 foot (900 millimeters) square grid.
Table 4. Timing of measurements for illuminance
If first measurement is taken in … take second measurement in …
January May-September
February June-October
March June-July, November-December
April August-December
May September-January
June October-February
July November-March
August December-April
September December-January, May-June
October February-June
November March-July
December April-August
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Addenda

4/21/2023Updated: 5/9/2023
Rating System Correction
Description of change:
For BDC Only:
Add the following language to the first sentence: "For core and shell projects, glare-control devices are not required in the spaces to be fit-out by the tenant(s).
Delete "only 1 or" and "or 1 additional point if only 1 point achieved above" from the last row of Table 1

IDC only:
Delete "only 1 or" from the last row of Table 1

Campus Applicable
No
Internationally Applicable:
No
8/12/2022Updated: 8/23/2022
Regional ACP
Description of change:
This is a Regional alternative compliance path to BD+C v4 EQc Daylight BD+C v4.1 EQc Daylight, ID+C v4 EQc Daylight and ID+C v4.1 EQc Daylight

Project must be located in a latitude of 55°N or above. (Projects located below 55°N, interested in using this pilot including those in the southern hemisphere may contact USGBC)

Perform annual computer simulations for spatial daylight autonomy 300/50% (sDA300/50%) and spatial daylight autonomy 100/50% (sDA100/50%) as defined in the European standard CEN 17037:2018 for each regularly occupied space. Healthcare projects must use each regularly occupied space located in the perimeter area determined under EQ Credit Quality Views. Additionally, calculate the average sDA values for the total regularly occupied floor area.

AND

Design the building to minimize glare and excessive daylight, considering both high and low sun angles. Meet one of the following:

  • Provide automated dynamic facade systems. If using this option, the system must be included in the sDA calculations.

  • Evaluate the regularly occupied spaces for annual daylight glare probability (DGP) as described in CEN 17037:2018. For minimum glare protection, target to not exceed 0.45 DGP for more than 5% of the occupation time of the space. Provide glare control devices for each regularly occupied space. For any regularly occupied spaces with DGP greater than 0.45 for more than 5% of the occupation time, identify how the space is designed to address glare.

  • Perform annual computer simulations for spatial daylight autonomy 3000/50% (sDA3000/50%) for each regularly occupied space. For minimum glare protection, each regularly occupied space must achieve sDA3000/50% of 0. Provide glare control devices for each regularly occupied space. Note that this approach is only available for this pilot for simplification purposes and should not be considered as a substitution of ASE. 3000 lux is very high illuminance threshold and occupants should never experience it for more than 50% of their time throughout a year. ASE is a more accurate metric than sDA to evaluate daylight excessiveness in buildings.

  • Perform annual computer simulations for annual sunlight exposure 1000,250 (ASE 1000,250) as defined in IES LM-83-12. For minimum glare protection, target ASE 1000,250 of 10% or less. Provide glare control devices for each regularly occupied space. For any regularly occupied spaces with ASE1000,250 greater than 10%, identify how the space is designed to address glare.




Points are awarded according to Table 1 (linked below).

The sDA calculation grids should be no more than 1-foot (300 millimeters) square and laid out across the regularly occupied area at a work plane height of 33.5 inches (850 millimeters) above finished floor (unless otherwise defined). The area of the grid points, within a space, should exclude a band of 19.5 inches (0.5 m) from the walls (unless otherwise specified). Use an hourly time-step analysis based on typical meteorological year data, or an equivalent, for the nearest available weather station. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

The DGP should be calculated where the person is likely to be positioned in the space, or if multiple positions are possible, the expected worst case position, at eye height of 47.2 inches (1200 millimeters) above finished floor (unless otherwise defined) in the primary viewing direction from that position. Include shading in the analysis. Only use DGP where it is expected that the vertical illuminance is a good indicator for the glare perception.


Submittals


  • Floor plans highlighting regularly occupied spaces

  • List of compliant spaces with their annual summary values for sDA100/50% and resulting average sDA100/50% value for the total regularly occupied floor area.

  • List of compliant spaces with their annual summary values for sDA300/50% and resulting average sDA300/50% value for the total regularly occupied floor area.

  • Geometric plots from simulations

  • Narrative or output file describing daylight simulation program, simulation inputs, and weather file

  • Description of design approach to minimize glare and excessive daylight including confirmation with one of the following options selected (1) automated dynamic façade systems, (2) annual daylight glare probability (DGP), (3) sDA3000/50%, (4) annual sunlight exposure (ASE 1000,250)

  • Results of design approach to minimize glare, including calculation details (for all options except dynamic façade systems) and (as applicable):

    • Automated dynamic façade systems: description of the system(s)

    • annual daylight glare probability (DGP): list of regularly occupied spaces and resulting DGP values. For spaces with values exceeding 0.45 more than 5%, explanation of how the space is designed to address glare.

    • sDA3000/50%: List of compliant spaces with their annual summary values for sDA3000/50%

    • Annual sunlight exposure (ASE 1000,250): List of regularly occupied spaces with their annual summary values for ASE 1000,250 . For spaces with values exceeding 10%, explanation of how the space is designed to address glare.




Campus Applicable
No
Internationally Applicable:
Yes
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USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To connect building occupants with the outdoors, reinforce circadian rhythms, and reduce the use of electrical lighting by introducing daylight into the space.

Requirements

Provide manual or automatic (with manual override) glare-control devices for all regularly occupied spaces. For core and shell projects, glare-control devices are not required in the spaces to be fit-out by the tenant(s).

AND

Select one of the following three options.

Option 1. Simulation: Spatial Daylight Autonomy and Annual Sunlight Exposure (1–3 points, 1-2 points Healthcare)

Perform annual computer simulations for spatial daylight autonomy300/50% (sDA300/50%), and annual sunlight exposure1000,250 (ASE1000,250 ) as defined in IES LM-83-12 for each regularly occupied space. Healthcare projects must use each regularly occupied space located in the perimeter area determined under EQ Credit Quality Views. Additionally, calculate the average sDA300/50% value for the total regularly occupied floor area.

For any regularly occupied spaces with ASE1000,250 greater than 10%, identify how the space is designed to address glare.

Points are awarded according to Table 1.

Table 1. Points for Option 1
New Construction, Core and Shell, Schools, Retail, Data Centers, Warehouses and Distribution Centers, Hospitality Healthcare
The average sDA300/50% value for the regularly occupied floor area is at least 40% 1 point 1 point
The average sDA300/50% value for the regularly occupied floor area is at least 55% 2 points 2 points
The average sDA300/50% value for the regularly occupied floor area is at least 75% 3 points Exemplary performance
Each regularly occupied space achieves sDA300/50% value of at least 55% Exemplary performance or 1 additional point if 2 points achieved above. Exemplary performance

The sDA and ASE calculation grids should be no more than 2 feet (600 millimeters) square and laid out across the regularly occupied area at a work plane height of 30 inches (760 millimeters) above finished floor (unless otherwise defined). Use an hourly time-step analysis based on typical meteorological year data, or an equivalent, for the nearest available weather station. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR
Option 2. Simulation: Illuminance Calculations (1–3 points, 1-2 points Healthcare)

Perform computer simulations for illuminance at 9 a.m. and 3 p.m. on a clear-sky day at the equinox for each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Demonstrate illuminance levels are between 300 lux and 3,000 lux at both 9 a.m. and 3 p.m. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 2.

Table 2. Points for Option 2
New Construction, Core and Shell, Schools, Retail, Data Centers, Warehouses and Distribution Centers, Hospitality Healthcare
Percentage of regularly occupied floor area Points Percentage of regularly occupied floor area within perimeter area Points
55% 1 55% 1
75% 2 75% 2
90% 3 90% Exemplary performance
Calculate illuminance intensity for sun (direct component) and sky (diffuse component) for clear-sky conditions as follows:
  • Use typical meteorological year data, or an equivalent, for the nearest available weather station.
  • Select one day within 15 days of September 21 and one day within 15 days of March 21 that represent the clearest sky condition.
  • Use the average of the hourly value for the two selected days.

Exclude blinds or shades from the model. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR
Option 3. Measurement (1-3 points, 1-2 points Healthcare)

Measure illuminance in each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Achieve illuminance levels between 300 lux and 3,000 lux. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 3.

Table 3. Points for Option 3
New Construction, Core and Schools, Schools, Retail, Data Centers, Warehouses and Distribution Centers, Hospitality Healthcare
Percentage of regularly occupied floor area Points Percentage of regularly occupied floor area within perimeter area
55% at one time in the year 1 55% at one time in the year 1
75% at two times in the year 2 75% at two times in the year 2
90% at two times in the year 3 90% at two times in the year exemplary performance
With furniture, fixtures, and equipment in place, measure illuminance levels as follows:
  • Measure at appropriate work plane height during any hour between 9 a.m. and 3 p.m.
  • If pursuing one point, take one measurement in any regularly occupied month. If pursuing two points, take two measurements: one measurement in any regularly occupied month, and take a second as indicated in Table 4.
  • For spaces larger than 150 square feet (14 square meters), take measurements on a maximum 10 foot (3 meter) square grid.
  • For spaces 150 square feet (14 square meters) or smaller, take measurements on a maximum 3 foot (900 millimeters) square grid.
Table 4. Timing of measurements for illuminance
If first measurement is taken in … take second measurement in …
January May-September
February June-October
March June-July, November-December
April August-December
May September-January
June October-February
July November-March
August December-April
September December-January, May-June
October February-June
November March-July
December April-August

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  • Sample templates to help guide your narratives and LEED Online submissions.
  • Examples of actual submissions from certified LEED projects.

LEEDuser expert

Daniel Glaser

LightStanza
Principal

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