LEED v2009
Neighborhood Development
Green infrastructure & buildings
Building energy efficiency

ND-v2009 GIBc2: Building energy efficiency

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Credit language

USGBC logo

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

Requirements

The following requirement applies to 90% of the building floor area (rounded up to the next whole building) of all nonresidential buildings, mixed-use buildings, and multiunit residential buildings four stories or more constructed as part of the project or undergoing major renovations as part of the project. New buildings must demonstrate an average 18% (1 point) or 26% (2 points) improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007, with errata but without addenda (or a USGBC-approved equivalent standard for projects outside the United States). Buildings undergoing major renovations as part of the project must demonstrate an average 14% (1 point) or 22% (2 points) improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007. For projects outside the United States, consult ANSI/ASHRAE/IESNA Standard 90.1–2010, Appendixes B and D, to determine the appropriate climate zone. Projects must document building energy efficiency using one or a combination of the following:

  1. Produce a LEED-compliant energy model following the methodology outlined in the LEED rating system appropriate to each building’s scope, including demonstration by a whole building project computer simulation using the building performance rating method in Appendix G of ANSI/ASHRAE/IESNA Standard 90.1–2007. Appendix G requires that the energy analysis done for the building performance rating method include all energy costs associated with the building project. Projects in California may use Title 24–2005, Part 6, in place of ANSI/ASHRAE/IESNA Standard 90.1–2007 (or USGBC approved equivalent standard for projects outside the United States).
  2. Comply with the prescriptive measures of the ASHRAE Advanced Energy Design Guide listed below, appropriate to each building’s scope. Comply with all applicable criteria as established in the guide for the climate zone in which the project is located. For projects outside the United States, consult ANSI/ASHRAE /IESNA Standard 90.1–2010, Appendixes B and D, to determine the appropriate climate zone.
    • ASHRAE Advanced Energy Design Guide for Small Office Buildings 2004 (office occupancy buildings less than 20,000 square feet or 1,800 square meters).
    • ASHRAE Advanced Energy Design Guide for Small Retail Buildings 2006 (retail occupancy buildings less than 20,000 square feet or 1,800 square meters).
    • ASHRAE Advanced Energy Design Guide for Small Warehouses and Self-Storage Buildings 2008 (warehouse or self-storage occupancy less than 50,000 square feet or 4,600 square meters).
    • ASHRAE Advanced Energy Design Guide for K–12 School Buildings (K–12 school occupancy less than 200,000 square feet or 18,600 square meters).
  3. For buildings less than 100,000 square feet (9,300 square meters), comply with the prescriptive measures identified in the Advanced Buildings™ Core Performance™ Guide developed by the New Buildings Institute, as follows:
    • Comply with Section 1, Design Process Strategies, and Section 2, Core Performance Requirements, of the Core Performance Guide.
    • Health care, warehouse and laboratory projects are ineligible for this path.
If method (a) is used for all of the floor area evaluated in this prerequisite, the total percentage improvement is calculated as a sum of energy costs for each building compared with a baseline. If any combination of methods (a), (b), and (c) is used, the total percentage improvement is calculated as a weighted average based on building floor area. In determining the weighted average, buildings pursuing (a) will be credited at the percentage value determined by the energy model. Buildings pursuing (b) or (c) will be credited at 12% better than ANSI/ASHRAE/IESNA Standard 90.1–2007 (or USGBC- approved equivalent standard for projects outside the United States) for new buildings and 8% better for existing building renovations.
AND
For new single-family residential buildings and new multiunit residential buildings three stories or fewer, 90% of the buildings must achieve a Home Energy Rating System (HERS) index (or a USGBC approved equivalent) score of at least 75. Project teams wishing to use ASHRAE-approved addenda for the purposes of this credit may do so at their discretion. Addenda must be applied consistently across all LEED credits.

Pilot Alternatives Available

The following pilot alternative compliance paths are available for this credit. See the pilot credit library for more information. EApc107 - Energy Performance Metering Path
See all forum discussions about this credit »

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Addenda

01/07/2014– Updated: 14/02/2015
Global ACP
Description of change:
100001884

Replace the second paragraph with the following: "New buildings must demonstrate an average 10% improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007,with errata but without addenda, (or a USGBC-approved equivalent standard for projects outside the United States). Buildings undergoing major renovations must demonstrate an average 5% improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007. For projects outside the United States, consult ANSI/ASHRAE /IESNA Standard 90.1–2007, Appendixes B and D, to determine the appropriate climate zone."

Add the following statement at the end of Section a: "(or a USGBC- approved equivalent standard for projects outside the United States.)" behind each requirement for using Appendix G of ANSI/ASHRAE/IESNA Standard 90.1–2007"

Add the following last sentence under Section b: "For projects outside the United States, consult ANSI/ASHRAE /IESNA Standard 90.1–2007, Appendixes B and D, to determine the appropriate climate zone."

Add the following statement: "(or USGBC- approved equivalent standard for projects outside the United States) for new buildings and 8% better for existing building renovations." under the second to last paragraph, behind: "Buildings pursuing (b) or (c) will be credited at 12% better than ANSI/ASHRAE/IESNA Standard 90.1–2007"

Add the following statement: "(or a USGBC- approved equivalent)" to the last paragraph, behind "Home Energy Rating System (HERS)" index.

Inquiry:
Ruling:
Campus Applicable
No
Internationally Applicable:
Yes
19/07/2010– Updated: 14/02/2015
Reference Guide Correction
Description of change:
ad-100000871

In the eighth line of the first paragraph of the first item, remove the parenthesis after "processes" so the text becomes "...or commercial processes. Building..."

Inquiry:
Ruling:
Campus Applicable
No
Internationally Applicable:
No
01/04/2012
LEED Interpretation
Description of change:
Inquiry:

Can we take credit for a demand ventilation system for an automotive service area?Essentially we propose to model the service area in the Baseline Cases at 100% outside air at 1.5 CFM/sq.ft. during occupied periods to meet ASHRAE 62.1. We plan to model the service area in the Proposed Case with typical storage ventilation rate. See rationale below to validate our assumptions.We further propose to model this energy efficiency measure in the standard credit energy models (not as an exceptional calculation) as part of the Baseline and Proposed Cases in order to accurately account for the differences in ventilation load. The differences are based on outside air conditions which change throughout the year and they also impact the supply air unit and fan sizes. The simulation program must size the equipment for the Baseline Case at the peak load and model it use 8760 hours in the year. ASHRAE 62.1 lists a specific minimum ventilation rate for automotive service areas at 1.5 CFM/sq. ft. Ventilation reduction controls are not stated in Ashrae 62.1, nor are they mandated in ASHRAE 90.1-2007. The governing Mechanical Code (International Mechanical Code) optionally permits the use of approved automatic detection devices to control the required ventilation fans and/or make-up air systems. Large make-up air systems providing 100% outside air are still readily available and utilized in order to meet the mandated code. We have utilized the following assumptions for modeling energy usage:Baseline Case - The exhaust ventilation system is modeled to operate at 1.5 CFM/sq.ft. during occupied hours per occupancy schedule. The modeling software automatically sizes the air conditioning system to operate as a 100% outside air system as the total CFM requirement exceeds the design load amount. The unoccupied fan cycle does not include the ventilation and only operates to maintain unoccupied thermostat set point.Proposed Case - The exhaust ventilation system is modeled to be non-operational at any time. We make this assumption based on calculation and witnessed operation at like facilities with the identical control system in place. We have calculated carbon monoxide production based upon maximum estimated daily vehicle round trips through the service area. Eighteen service stalls with an average of 3 vehicles per day and 1 minute round trip drive time yields an estimated total vehicle drive time in the service area to be 54 minutes. The average modern vehicle with catalytic converter produces approximately 150 CFM of exhaust airflow at idle to slow speed containing approximately 1,000 PPM of carbon monoxide. 150 CFM X (0.1%) = 0.15 CFM of carbon monoxide production. The requirement to engage the exhaust ventilation system is 50 PPM of carbon monoxide. The volume of the space is 236,900 cu.ft. and would require 11.845 cu.ft. of carbon monoxide to engage the system. This would require 78.97 minutes of continuous operation without any dilution in a facility this size which exceeds the estimated maximum vehicle operation time of 54 minutes by 30%. The air conditioning equipment serving the area provides 800 CFM outside air and is equivalent to a complete air change twice a day and therefore doubling the daily total required operation time to 157.94 minutes. Operation of vehicles for diagnostic testing is excluded as there is a separate tailpipe extraction system in place to remove all exhaust during testing. Calculations are no substitute for actual conditions. We have interviewed service managers as to the operations of the emergency exhaust system controlled with a CO monitor system. The feed back is overwhelming that the emergency system is never engaged during normal operation. The technicians in these facilities have been trained in the control systems operations and do not desire to have their "conditioned" air purged from the building due to excessive operation of the vehicles within the space.

Ruling:

A project team cannot be awarded credit for demand controlled ventilation in an automotive service area, due to concerns over contaminants, and possible effects on indoor evironmental quality. As there is no current accepted methodology, the potential human health risks outweigh the energy savings.

Campus Applicable
No
Internationally Applicable:
No
See all forum discussions about this credit »

Credit language

USGBC logo

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

Requirements

The following requirement applies to 90% of the building floor area (rounded up to the next whole building) of all nonresidential buildings, mixed-use buildings, and multiunit residential buildings four stories or more constructed as part of the project or undergoing major renovations as part of the project. New buildings must demonstrate an average 18% (1 point) or 26% (2 points) improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007, with errata but without addenda (or a USGBC-approved equivalent standard for projects outside the United States). Buildings undergoing major renovations as part of the project must demonstrate an average 14% (1 point) or 22% (2 points) improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007. For projects outside the United States, consult ANSI/ASHRAE/IESNA Standard 90.1–2010, Appendixes B and D, to determine the appropriate climate zone. Projects must document building energy efficiency using one or a combination of the following:

  1. Produce a LEED-compliant energy model following the methodology outlined in the LEED rating system appropriate to each building’s scope, including demonstration by a whole building project computer simulation using the building performance rating method in Appendix G of ANSI/ASHRAE/IESNA Standard 90.1–2007. Appendix G requires that the energy analysis done for the building performance rating method include all energy costs associated with the building project. Projects in California may use Title 24–2005, Part 6, in place of ANSI/ASHRAE/IESNA Standard 90.1–2007 (or USGBC approved equivalent standard for projects outside the United States).
  2. Comply with the prescriptive measures of the ASHRAE Advanced Energy Design Guide listed below, appropriate to each building’s scope. Comply with all applicable criteria as established in the guide for the climate zone in which the project is located. For projects outside the United States, consult ANSI/ASHRAE /IESNA Standard 90.1–2010, Appendixes B and D, to determine the appropriate climate zone.
    • ASHRAE Advanced Energy Design Guide for Small Office Buildings 2004 (office occupancy buildings less than 20,000 square feet or 1,800 square meters).
    • ASHRAE Advanced Energy Design Guide for Small Retail Buildings 2006 (retail occupancy buildings less than 20,000 square feet or 1,800 square meters).
    • ASHRAE Advanced Energy Design Guide for Small Warehouses and Self-Storage Buildings 2008 (warehouse or self-storage occupancy less than 50,000 square feet or 4,600 square meters).
    • ASHRAE Advanced Energy Design Guide for K–12 School Buildings (K–12 school occupancy less than 200,000 square feet or 18,600 square meters).
  3. For buildings less than 100,000 square feet (9,300 square meters), comply with the prescriptive measures identified in the Advanced Buildings™ Core Performance™ Guide developed by the New Buildings Institute, as follows:
    • Comply with Section 1, Design Process Strategies, and Section 2, Core Performance Requirements, of the Core Performance Guide.
    • Health care, warehouse and laboratory projects are ineligible for this path.
If method (a) is used for all of the floor area evaluated in this prerequisite, the total percentage improvement is calculated as a sum of energy costs for each building compared with a baseline. If any combination of methods (a), (b), and (c) is used, the total percentage improvement is calculated as a weighted average based on building floor area. In determining the weighted average, buildings pursuing (a) will be credited at the percentage value determined by the energy model. Buildings pursuing (b) or (c) will be credited at 12% better than ANSI/ASHRAE/IESNA Standard 90.1–2007 (or USGBC- approved equivalent standard for projects outside the United States) for new buildings and 8% better for existing building renovations.
AND
For new single-family residential buildings and new multiunit residential buildings three stories or fewer, 90% of the buildings must achieve a Home Energy Rating System (HERS) index (or a USGBC approved equivalent) score of at least 75. Project teams wishing to use ASHRAE-approved addenda for the purposes of this credit may do so at their discretion. Addenda must be applied consistently across all LEED credits.

Pilot Alternatives Available

The following pilot alternative compliance paths are available for this credit. See the pilot credit library for more information. EApc107 - Energy Performance Metering Path
See all forum discussions about this credit »

Addenda

01/07/2014– Updated: 14/02/2015
Global ACP
Description of change:
100001884

Replace the second paragraph with the following: "New buildings must demonstrate an average 10% improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007,with errata but without addenda, (or a USGBC-approved equivalent standard for projects outside the United States). Buildings undergoing major renovations must demonstrate an average 5% improvement over ANSI/ASHRAE/IESNA Standard 90.1–2007. For projects outside the United States, consult ANSI/ASHRAE /IESNA Standard 90.1–2007, Appendixes B and D, to determine the appropriate climate zone."

Add the following statement at the end of Section a: "(or a USGBC- approved equivalent standard for projects outside the United States.)" behind each requirement for using Appendix G of ANSI/ASHRAE/IESNA Standard 90.1–2007"

Add the following last sentence under Section b: "For projects outside the United States, consult ANSI/ASHRAE /IESNA Standard 90.1–2007, Appendixes B and D, to determine the appropriate climate zone."

Add the following statement: "(or USGBC- approved equivalent standard for projects outside the United States) for new buildings and 8% better for existing building renovations." under the second to last paragraph, behind: "Buildings pursuing (b) or (c) will be credited at 12% better than ANSI/ASHRAE/IESNA Standard 90.1–2007"

Add the following statement: "(or a USGBC- approved equivalent)" to the last paragraph, behind "Home Energy Rating System (HERS)" index.

Inquiry:
Ruling:
Campus Applicable
No
Internationally Applicable:
Yes
19/07/2010– Updated: 14/02/2015
Reference Guide Correction
Description of change:
ad-100000871

In the eighth line of the first paragraph of the first item, remove the parenthesis after "processes" so the text becomes "...or commercial processes. Building..."

Inquiry:
Ruling:
Campus Applicable
No
Internationally Applicable:
No
01/04/2012
LEED Interpretation
Description of change:
Inquiry:

Can we take credit for a demand ventilation system for an automotive service area?Essentially we propose to model the service area in the Baseline Cases at 100% outside air at 1.5 CFM/sq.ft. during occupied periods to meet ASHRAE 62.1. We plan to model the service area in the Proposed Case with typical storage ventilation rate. See rationale below to validate our assumptions.We further propose to model this energy efficiency measure in the standard credit energy models (not as an exceptional calculation) as part of the Baseline and Proposed Cases in order to accurately account for the differences in ventilation load. The differences are based on outside air conditions which change throughout the year and they also impact the supply air unit and fan sizes. The simulation program must size the equipment for the Baseline Case at the peak load and model it use 8760 hours in the year. ASHRAE 62.1 lists a specific minimum ventilation rate for automotive service areas at 1.5 CFM/sq. ft. Ventilation reduction controls are not stated in Ashrae 62.1, nor are they mandated in ASHRAE 90.1-2007. The governing Mechanical Code (International Mechanical Code) optionally permits the use of approved automatic detection devices to control the required ventilation fans and/or make-up air systems. Large make-up air systems providing 100% outside air are still readily available and utilized in order to meet the mandated code. We have utilized the following assumptions for modeling energy usage:Baseline Case - The exhaust ventilation system is modeled to operate at 1.5 CFM/sq.ft. during occupied hours per occupancy schedule. The modeling software automatically sizes the air conditioning system to operate as a 100% outside air system as the total CFM requirement exceeds the design load amount. The unoccupied fan cycle does not include the ventilation and only operates to maintain unoccupied thermostat set point.Proposed Case - The exhaust ventilation system is modeled to be non-operational at any time. We make this assumption based on calculation and witnessed operation at like facilities with the identical control system in place. We have calculated carbon monoxide production based upon maximum estimated daily vehicle round trips through the service area. Eighteen service stalls with an average of 3 vehicles per day and 1 minute round trip drive time yields an estimated total vehicle drive time in the service area to be 54 minutes. The average modern vehicle with catalytic converter produces approximately 150 CFM of exhaust airflow at idle to slow speed containing approximately 1,000 PPM of carbon monoxide. 150 CFM X (0.1%) = 0.15 CFM of carbon monoxide production. The requirement to engage the exhaust ventilation system is 50 PPM of carbon monoxide. The volume of the space is 236,900 cu.ft. and would require 11.845 cu.ft. of carbon monoxide to engage the system. This would require 78.97 minutes of continuous operation without any dilution in a facility this size which exceeds the estimated maximum vehicle operation time of 54 minutes by 30%. The air conditioning equipment serving the area provides 800 CFM outside air and is equivalent to a complete air change twice a day and therefore doubling the daily total required operation time to 157.94 minutes. Operation of vehicles for diagnostic testing is excluded as there is a separate tailpipe extraction system in place to remove all exhaust during testing. Calculations are no substitute for actual conditions. We have interviewed service managers as to the operations of the emergency exhaust system controlled with a CO monitor system. The feed back is overwhelming that the emergency system is never engaged during normal operation. The technicians in these facilities have been trained in the control systems operations and do not desire to have their "conditioned" air purged from the building due to excessive operation of the vehicles within the space.

Ruling:

A project team cannot be awarded credit for demand controlled ventilation in an automotive service area, due to concerns over contaminants, and possible effects on indoor evironmental quality. As there is no current accepted methodology, the potential human health risks outweigh the energy savings.

Campus Applicable
No
Internationally Applicable:
No
See all forum discussions about this credit »
See all forum discussions about this credit »