SPECIAL REPORT
LEEDuser expert
TODD REED
PA DMVA
Energy Program Specialist
SPECIAL REPORT
LEEDuser’s viewpoint
Frank advice from LEED experts
LEED is changing all the time, and every project is unique. Even seasoned professionals can miss a critical detail and lose a credit or even a prerequisite at the last minute. Our expert advice guides our LEEDuser Premium members and saves you valuable time.
Credit language
© 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.
Select one of the following three options.
Option 1. Simulation: Spatial Daylight Autonomy (2–3 points)
Demonstrate through annual computer simulations that spatial daylight autonomy300/50% (sDA300/50%) of at least 55%, 75%, or 90% is achieved. Use regularly occupied floor area. Points are awarded according to Table 1.
Table 1. Points for daylit floor area: Spatial daylight autonomy
AND
Demonstrate through annual computer simulations that annual sunlight exposure1000,250 (ASE1000,250) of no more than 10% is achieved. Use the regularly occupied floor area that is daylit per the sDA300/50% simulations.
The sDA and ASE calculation grids should be no more than 2 feet (60 cm) square and laid out across the regularly occupied area at a work plane height of 30 inches (760 mm) 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 and movable furniture and partitions.
Option 2. Simulation: Illuminance Calculations (1–2 points)
Demonstrate through computer modeling that illuminance levels will be between 300 lux and 3,000 lux for 9 a.m. and 3 p.m., both on a clear-sky day at the equinox, for the floor area indicated in Table 2. Use regularly occupied floor area.
Table 2. Points for daylit floor area: Illuminance calculation
| CI, CI Retail, CI Hospitality | |
|---|---|
| Percentage of regularly occupied floor area | Points |
| 75% | 1 |
| 90% | 2 |
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.
- Measure at appropriate work plane height during any hour between 9 a.m. and 3 p.m.
- Take 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.
Exclude blinds or shades from the model.
Include any permanent interior obstructions and movable furniture and partitions.
Option 3. Measurement (2-3 points, 1-2 points Healthcare)
Achieve illuminance levels between 300 lux and 3,000 lux for the floor area indicated in Table 3.
Table 3. Points for daylit floor area: Measurement
| NC, CS, Schools, Retail, Data Centers, Warehouses & Distribution Centers, Hospitality, CI | Healthcare | ||
|---|---|---|---|
| Percentage of regularly occupied floor area | Points | Percentage of perimeter floor area | Points |
| 75 | 2 | 75 | 1 |
| 90 | 3 | 90 | 2 |
With furniture, fixtures, and equipment in place, measure illuminance levels as follows:
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 |
What does it cost?
Cost estimates for this credit
On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.
Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.
This information is also available in a full PDF download in The Cost of LEED v4 report.
Learn more about The Cost of LEED v4 »Documentation toolkit
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LEEDuser’s Documentation Toolkit is loaded with calculators to help assess credit compliance, tracking spreadsheets for materials, sample templates to help guide your narratives and LEED Online submissions, and examples of actual submissions from certified LEED projects for you to check your work against. To get your plaque, start with the right toolkit.
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© 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.
Select one of the following three options.
Option 1. Simulation: Spatial Daylight Autonomy (2–3 points)
Demonstrate through annual computer simulations that spatial daylight autonomy300/50% (sDA300/50%) of at least 55%, 75%, or 90% is achieved. Use regularly occupied floor area. Points are awarded according to Table 1.
Table 1. Points for daylit floor area: Spatial daylight autonomy
AND
Demonstrate through annual computer simulations that annual sunlight exposure1000,250 (ASE1000,250) of no more than 10% is achieved. Use the regularly occupied floor area that is daylit per the sDA300/50% simulations.
The sDA and ASE calculation grids should be no more than 2 feet (60 cm) square and laid out across the regularly occupied area at a work plane height of 30 inches (760 mm) 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 and movable furniture and partitions.
Option 2. Simulation: Illuminance Calculations (1–2 points)
Demonstrate through computer modeling that illuminance levels will be between 300 lux and 3,000 lux for 9 a.m. and 3 p.m., both on a clear-sky day at the equinox, for the floor area indicated in Table 2. Use regularly occupied floor area.
Table 2. Points for daylit floor area: Illuminance calculation
| CI, CI Retail, CI Hospitality | |
|---|---|
| Percentage of regularly occupied floor area | Points |
| 75% | 1 |
| 90% | 2 |
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.
- Measure at appropriate work plane height during any hour between 9 a.m. and 3 p.m.
- Take 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.
Exclude blinds or shades from the model.
Include any permanent interior obstructions and movable furniture and partitions.
Option 3. Measurement (2-3 points, 1-2 points Healthcare)
Achieve illuminance levels between 300 lux and 3,000 lux for the floor area indicated in Table 3.
Table 3. Points for daylit floor area: Measurement
| NC, CS, Schools, Retail, Data Centers, Warehouses & Distribution Centers, Hospitality, CI | Healthcare | ||
|---|---|---|---|
| Percentage of regularly occupied floor area | Points | Percentage of perimeter floor area | Points |
| 75 | 2 | 75 | 1 |
| 90 | 3 | 90 | 2 |
With furniture, fixtures, and equipment in place, measure illuminance levels as follows:
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 |
Cost estimates for this credit
On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.
Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.
This information is also available in a full PDF download in The Cost of LEED v4 report.
Learn more about The Cost of LEED v4 »In the end, LEED is all about documentation. LEEDuser’s Documentation Toolkit, for premium members only, saves you time and helps you avoid mistakes with:
- Calculators to help assess credit compliance.
- Tracking spreadsheets for materials purchases.
- Spreadsheets and forms to give to subs and other team members.
- Guidance documents on arcane LEED issues.
- Sample templates to help guide your narratives and LEED Online submissions.
- Examples of actual submissions from certified LEED projects.
LEEDuser expert
TODD REED
PA DMVA
Energy Program Specialist