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LEED v4.1

Existing Buildings

Indoor Environmental Quality
Indoor Environmental Quality Performance

LEED CREDIT

EBOM-v4.1 EQc1: Indoor Environmental Quality Performance 8-20 points

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SPECIAL REPORT

LEEDuser expert

Trista Little

LEED AP O+M, BD+C, Fitwel Ambassador

WSP USA
Project Director

SPECIAL REPORT

LEEDuser’s viewpoint

Explore this LEED credit

Post your questions on this credit in the forum, and click on the credit language tab to review to the LEED requirements.

Credit language

USGBC logo

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

Intent

To assess how well the building is performing for the occupants, in particular with regards to indoor air quality and comfort.

Requirements

Conduct an occupant satisfaction survey and/or an indoor air quality evaluation.

For the occupant satisfaction survey, regular building occupants must be surveyed. The required number of responses that must be received is outlined in Figure 1.

For the indoor air quality evaluation, test for any of the following contaminants:

  • Inorganic Contaminants:
    • Carbon Monoxide (CO)
    • Carbon Dioxide (CO2)
    • Ozone (O3)
    • PM2.5
  • Volatile Organic Compounds:
    • Acetaldehyde (75-07-0)
    • Benzene (71-43-2)
    • Styrene (100-42-5)
    • Toluene (108-88-3)
    • Naphthalene (91-20-3)
    • Dichlorobenzene (1,4-) (106-46-7)
    • Xylenes-total (108-38-3, 95-47-6, and 106-42-3)
    • Formaldehyde (50-00-0)
    • Total volatile organic compounds (TVOC) (as defined in ISO 16000-6)

Points are awarded based on the results from the CO2 and TVOC measurements.

Take the indoor air measurements in locations representative of all occupied spaces, within the breathing zone (between 3 and 6 feet (900 and 1800 millimeters) above the floor), during normal occupied hours, under typical minimum ventilation conditions.

Conduct the survey at least once per year, using the Arc Platform, and calculate an Occupant Satisfaction Score for the project.

Conduct at least one indoor air quality evaluation per year. Input measured contaminant levels into the Arc Platform and calculate a CO2 Score and TVOC score for the project.

Obtain a minimum Human Experience Score of 40. Additional points for this prerequisite are awarded for Human Experience Scores above 40, according to Table 1.

The Human Experience Score is based on three components which are weighted differently:

  1. Occupant satisfaction score (50% weighting)
  2. CO2 score (25% weighing)
  3. TVOC score (25% weighting)
Table 1. LEED Points for Human Experience

Human Experience Score LEED Points
40 (Required) 8 (Required)
43 9
48 10
53 11
58 12
63 13
68 14
73 15
78 16
83 17
88 18
93 19
98 20

Figure 1. Required Response Rates as a Product of Building Occupancy

Equation: Response rate= 100 * (0.25 / square root (occupancy / 500))

Occupant satisfaction score
The occupant satisfaction score rates the satisfaction occupants have with the building against satisfaction of occupants of comparable LEED certified buildings.

The score is a value from 1-100 based on the project’s average occupant satisfaction level taking and the variance in the occupant responses.

Occupant Satisfaction Score calculation
To calculate an occupant satisfaction score, the following data is required. All data is collected via the occupant satisfaction survey. At least one survey every 365 days must be conducted:

  1. Number of regular building occupants and visitors
  2. For Hospitality projects, number of hotel or lodging guests (these occupants may be excluded from the survey)
  3. Occupant satisfaction level (for each survey response)

The projects occupant satisfaction score is calculated by taking the average of the satisfaction levels for each building occupant that completes the survey, and considering the variance in the responses, using Equation 1.

Equation 1: Occupant satisfaction score = (Average occupant satisfaction level x 10) - variance in occupant satisfaction level

CO2 score

The CO2 score rates the building’s CO2 levels against the industry benchmark level of 1000 ppm.

The score is a value from 1-100 based on the project’s average 95th percentile CO2 value.

CO2 score calculation
To calculate a CO2 score, the following data is required:

  1. Measurement location
  2. Date and time for each measurement
  3. Measured CO2 concentration (ppm)

The 95th percentile value for each location (CO295th) is calculated. The 95th percentile is the CO2 value where 95% of the data falls below.

An average CO295th value is calculated for the indoor environmental quality evaluation.

The project’s average CO295th value is then input into the CO2 scoring function (see Figure 2) to produce a CO2 score for the project.

Figure 2. CO2 scoring function

The CO2 scoring function was developed based on the industry benchmark level of 1000 ppm.

TVOC Score
The TVOC score rates the building’s TVOC levels against the industry benchmark level of 500 µg/m3.

The score is a value from 1-100 based on the project’s maximum TVOC value.

TVOC score calculation
To calculate a TVOC score, the following data is required:

  • Measurement location
  • Measurement date(s)
  • Start and end time(s) for each measurement
  • Measured TVOC concentration (µg/m3)

An average TVOC level (TVOCavg) is calculated for each location by averaging all of the TVOC measurements taken at that location during the indoor air quality evaluation.

A maximum TVOC level (TVOCmax) is determined by taking the highest TVOCavg value for the indoor environmental quality evaluation.

The project’s maximum TVOC level (TVOCmax) is then input into the TVOC scoring function to produce a TVOC score for the project.

The TVOC scoring function was developed based on the LEED TVOC limit of 500 µg/m3.

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Cost estimates for this credit

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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 »

Addenda

7/25/2019Updated: 11/6/2020
Reference Guide Correction
Description of change:
Under Guidance, above step-by-step add:
At this time the additional inorganic contaminants and volatile organic compounds are not included in the human experience score. For a more comprehensive indoor air quality evaluation, projects are encouraged to include all or some of these additional contaminants in their measurements. An additional point under the Innovation credit is available for projects that include two additional contaminants.

Under step-by-step:
add new paragraph:
Complete steps 1-4 as applicable. For this prerequisite, at least one of the three components of the Human Experience score (occupants satisfaction score, CO2 score, or TVOC score) must be pursued. Projects are encouraged to pursue all three components.

Step 1. Conduct an occupant satisfaction survey
Replace "transportation survey" with "occupant comfort survey."

Step 2. Achieve required response rate from the survey
Remove "Figure 1 in" from first sentence.

Step 3. Conduct an indoor air quality evaluation for the project
Add two paragraphs at the end:
The project team may use any measurement method capable of measuring CO2 and/or TVOC and use their best judgement when determining the number of sampling locations, and frequency and duration of testing. Laboratory-based test methods for TVOC are recommended but not required. If desired, the measurement methods and testing approaches outlined in following related LEED credits may be used: LEED v4.1 or LEED v4 BD+C credit Indoor Air Assessment, LEED 2009 BD+C credit Construction Indoor Air Quality Management Plan – Before Occupancy, and/or LEED v4 O+M Performance Based Indoor Air Assessment in Existing Buildings.

For TVOC, measurements must be provided in µg/m3. Use correction factors and/or conversion factors applicable to the instrument being used when converting from ppm to µg/m3 and note any assumptions in the evaluation report.


Under Required Documentation replace second bullet with:

Indoor air quality evaluation report, including narrative explaining how test locations were determined, dates, times, and results of each test, and measurement methods. If TVOC readings were taken in other units (such as ppm), include calculation details with any conversion/correction factors used.
Campus Applicable
No
Internationally Applicable:
Yes
7/25/2019Updated: 11/6/2020
Reference Guide Correction
Description of change:
Remove the following:

LT prerequisite Transportation Performance
"Note: at this time, the transportation performance score calculated is only based on one-way, one-day survey information. USGBC is in the process of updating the survey platform and scoring to include two-way one-week information."

EA prerequisite Energy Performance
"Note: at this time, the energy performance score calculated is only based on GHG emissions. USGBC is in the process of updating the scoring to include source energy. In the meantime, projects are eligible to earn up to the full 33 points based GHG emissions score."

EQ prerequisite Indoor Environmental Quality Performance
"Note: at this time, the Human Experience score is calculated as one-third occupant satisfaction score, one-third CO2 score, and one-third TVOC score. USGBC is in the process of updating the scoring to be half occupant satisfaction, one-quarter CO2 score, and one-quarter TVOC score (as specified in the rating system language)."
Campus Applicable
No
Internationally Applicable:
Yes
4/9/2019Updated: 4/9/2019
Rating System Correction
Description of change:
Add "(Required)" after the 40 point threshold
Campus Applicable
No
Internationally Applicable:
No
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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.

LEEDuser expert

Trista Little

LEED AP O+M, BD+C, Fitwel Ambassador

WSP USA
Project Director

USGBC logo

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

Intent

To assess how well the building is performing for the occupants, in particular with regards to indoor air quality and comfort.

Requirements

Conduct an occupant satisfaction survey and/or an indoor air quality evaluation.

For the occupant satisfaction survey, regular building occupants must be surveyed. The required number of responses that must be received is outlined in Figure 1.

For the indoor air quality evaluation, test for any of the following contaminants:

  • Inorganic Contaminants:
    • Carbon Monoxide (CO)
    • Carbon Dioxide (CO2)
    • Ozone (O3)
    • PM2.5
  • Volatile Organic Compounds:
    • Acetaldehyde (75-07-0)
    • Benzene (71-43-2)
    • Styrene (100-42-5)
    • Toluene (108-88-3)
    • Naphthalene (91-20-3)
    • Dichlorobenzene (1,4-) (106-46-7)
    • Xylenes-total (108-38-3, 95-47-6, and 106-42-3)
    • Formaldehyde (50-00-0)
    • Total volatile organic compounds (TVOC) (as defined in ISO 16000-6)

Points are awarded based on the results from the CO2 and TVOC measurements.

Take the indoor air measurements in locations representative of all occupied spaces, within the breathing zone (between 3 and 6 feet (900 and 1800 millimeters) above the floor), during normal occupied hours, under typical minimum ventilation conditions.

Conduct the survey at least once per year, using the Arc Platform, and calculate an Occupant Satisfaction Score for the project.

Conduct at least one indoor air quality evaluation per year. Input measured contaminant levels into the Arc Platform and calculate a CO2 Score and TVOC score for the project.

Obtain a minimum Human Experience Score of 40. Additional points for this prerequisite are awarded for Human Experience Scores above 40, according to Table 1.

The Human Experience Score is based on three components which are weighted differently:

  1. Occupant satisfaction score (50% weighting)
  2. CO2 score (25% weighing)
  3. TVOC score (25% weighting)
Table 1. LEED Points for Human Experience

Human Experience Score LEED Points
40 (Required) 8 (Required)
43 9
48 10
53 11
58 12
63 13
68 14
73 15
78 16
83 17
88 18
93 19
98 20

Figure 1. Required Response Rates as a Product of Building Occupancy

Equation: Response rate= 100 * (0.25 / square root (occupancy / 500))

Occupant satisfaction score
The occupant satisfaction score rates the satisfaction occupants have with the building against satisfaction of occupants of comparable LEED certified buildings.

The score is a value from 1-100 based on the project’s average occupant satisfaction level taking and the variance in the occupant responses.

Occupant Satisfaction Score calculation
To calculate an occupant satisfaction score, the following data is required. All data is collected via the occupant satisfaction survey. At least one survey every 365 days must be conducted:

  1. Number of regular building occupants and visitors
  2. For Hospitality projects, number of hotel or lodging guests (these occupants may be excluded from the survey)
  3. Occupant satisfaction level (for each survey response)

The projects occupant satisfaction score is calculated by taking the average of the satisfaction levels for each building occupant that completes the survey, and considering the variance in the responses, using Equation 1.

Equation 1: Occupant satisfaction score = (Average occupant satisfaction level x 10) - variance in occupant satisfaction level

CO2 score

The CO2 score rates the building’s CO2 levels against the industry benchmark level of 1000 ppm.

The score is a value from 1-100 based on the project’s average 95th percentile CO2 value.

CO2 score calculation
To calculate a CO2 score, the following data is required:

  1. Measurement location
  2. Date and time for each measurement
  3. Measured CO2 concentration (ppm)

The 95th percentile value for each location (CO295th) is calculated. The 95th percentile is the CO2 value where 95% of the data falls below.

An average CO295th value is calculated for the indoor environmental quality evaluation.

The project’s average CO295th value is then input into the CO2 scoring function (see Figure 2) to produce a CO2 score for the project.

Figure 2. CO2 scoring function

The CO2 scoring function was developed based on the industry benchmark level of 1000 ppm.

TVOC Score
The TVOC score rates the building’s TVOC levels against the industry benchmark level of 500 µg/m3.

The score is a value from 1-100 based on the project’s maximum TVOC value.

TVOC score calculation
To calculate a TVOC score, the following data is required:

  • Measurement location
  • Measurement date(s)
  • Start and end time(s) for each measurement
  • Measured TVOC concentration (µg/m3)

An average TVOC level (TVOCavg) is calculated for each location by averaging all of the TVOC measurements taken at that location during the indoor air quality evaluation.

A maximum TVOC level (TVOCmax) is determined by taking the highest TVOCavg value for the indoor environmental quality evaluation.

The project’s maximum TVOC level (TVOCmax) is then input into the TVOC scoring function to produce a TVOC score for the project.

The TVOC scoring function was developed based on the LEED TVOC limit of 500 µg/m3.

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

Trista Little

LEED AP O+M, BD+C, Fitwel Ambassador

WSP USA
Project Director

See all LEEDuser forum discussions about this credit » Unsubscribe from discussions about EBOM-v4.1 EQc1