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LEED v4.1
New Construction
Materials and Resources
Building Life-Cycle Impact Reduction

LEED CREDIT

NC-v4.1 MRc1: Building life-cycle impact reduction 2-5 points

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View the LEED v4 version of this credit »

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Sarah Buffaloe

AIA, LEED AP BD+C

WSP USA
Associate, Built Ecology

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Credit language

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

Intent

To encourage adaptive reuse and optimize the environmental performance of products and materials.

Requirements

Demonstrate reduced environmental effects during initial project decision-making by reusing existing building resources or demonstrating a reduction in materials use through life-cycle assessment.

Achieve one or more of the following options below for a maximum of 5 points.

Option 1. Building and Material Reuse (1-5 points)

Maintain the existing building structure, envelope, and interior nonstructural elements. Reused or salvaged materials from off site that are incorporated into the building can also contribute to the credit calculations. However, reuse materials contributing toward this credit may not contribute toward MR credit- Sourcing of Raw Materials.

Historic, abandoned or blighted buildings: Portions of buildings deemed structurally unsound or hazardous can be excluded from the credit calculations.

Path 1 and 2 reward projects that reuse structural and/or nonstructural elements based on the project area. Path 1 and 2 can be combined for points.


Path 1: Maintain Existing Structural Elements: Walls, Floors, Roofs, and Envelope (1-5 points)

Maintain the existing building structure (including floor and roof decking) and envelope (the exterior skin and framing, excluding window assemblies and nonstructural roofing materials). Calculate reuse of the existing project area according to Table 1.

Table 1. Path 1 Points for reuse of existing building structural elements.

Percent of existing walls, floors and roof reuse by project area Points BD+C
15% 1
30% 2
45% 3
60% 4
75% 5
AND/OR

Path 2: Maintain Interior Non structural Elements (1 point)

Use existing interior nonstructural elements (e.g. interior walls, doors, floor coverings and ceiling systems) for at least 30% of the entire completed building, including additions.

AND/OR
Option 2. Whole-Building Life-Cycle Assessment (1-4 points)

For new construction (buildings or portions of buildings), conduct a cradle-to-grave life-cycle assessment of the project’s structure and enclosure and select one or more of the following paths below to earn up to 4 points:

Path 1: Conduct a life cycle assessment of the project’s structure and enclosure (1 point).

Path 2: Conduct a life cycle assessment of the project’s structure and enclosure that demonstrates a minimum of 5% reduction, compared with a baseline building in at least three of the six impact categories listed below, one of which must be global warming potential (2 points).

Path 3: Conduct a life cycle assessment of the project’s structure and enclosure that demonstrates a minimum of 10% reduction, compared with a baseline building, in at least three of the six impact categories listed below, one of which must be global warming potential (3 points).

Path 4: Meet requirements of Path 3 and incorporate reuse and/or salvage materials into the project’s structure and enclosure for the proposed design. Demonstrate reductions compared with a baseline building of at least 20% reduction for global warming potential and demonstrate at least 10% reduction in two additional impact categories listed below (4 points).

For Paths 2, 3 and 4 listed above, no impact category assessed as part of the life-cycle assessment may increase by more than 5% compared with the baseline building. Include a narrative of how the life cycle assessment was conducted and if applicable for paths 2, 3 and 4 what changes were made to proposed buildings in order to achieve the related impact reductions.

The baseline and proposed buildings must be of comparable size, function, orientation, and operating energy performance as defined in EA Prerequisite Minimum Energy Performance. The service life of the baseline and proposed buildings must be the same and at least 60 years to fully account for maintenance and replacement. Baseline assumptions must be based on standard design and material selection for the project location and building type. Use the same life-cycle assessment software tools and data sets to evaluate both the baseline building and the proposed building, and report all listed impact categories. Data sets must be compliant with ISO 14044.

Select at least three of the following impact categories for reduction:
  • global warming potential (greenhouse gases), in kg CO2e;
  • depletion of the stratospheric ozone layer, in kg CFC-11e;
  • acidification of land and water sources, in moles H+ or kg SO2e;
  • eutrophication, in kg nitrogen eq or kg phosphate eq;
  • formation of tropospheric ozone, in kg NOx, kg O3 eq, or kg ethene; and
  • depletion of nonrenewable energy resources, in MJ using CML / depletion of fossil fuels in TRACI.
Europe ACP: Option 4 Whole Building Life-Cycle Assessment

For European projects, EN standard 15978 may be used as framework for the Life-Cycle-Assessment instead of ISO 14044 for this credit. Where implementation of EN 15978 conflicts with any of requirements of this credit, the credit requirements prevail, including the life-cycle stages required and treatment of EPD data (See Further Explanation - Incorporation of EPD data in WBLCA Tools). Note that the CML indicators are acceptable per the Further Explanation section of the Reference Guide language of this credit. Projects will still need to meet the individual requirements of the pathway chosen for this credit option.

Further Explanation - Incorporation of EPD data in WBLCA Tools: Combining EPD impacts with WBLCA results shall follow the best practice guidance outlined in Athena Guide to Whole Building LCA in Green Building Programs which stipulates that EPD results may only be combined provided the EPD:

  • Has not expired;
  • EPD scenarios should be representative of contemporary technologies and/or practice, and the project location;
  • Reports all indicators and system boundary information modules required by the WBLCA tool;
  • Characterizes the impact categories reported according to the same LCA methodology as the WBLCA tool;
  • Can be applied to the study period of the assessment;
  • Clearly indicates which product (including manufacturer and product name) or geographical region it reflects in comparison to the industry-wide weighted average results of a material or fuel already available in the tool.
Additionally, comparability shall be ensured in accordance with Section 5 of the BRE Briefing Paper "Assessing the environmental impacts of construction – understanding European Standards and their implications."
Europe ACP: Whole-Building LCA according to the Level(s) framework


The approach for a Europe ACP is for projects which fulfil the Level(s) criteria, to earn points in the LEED MR credit: Building Life-Cycle Impact Reduction accordingly.

For new construction (buildings or portions of buildings), select one or more of the following paths below to earn up to 4 points:

Path 1: Fulfill the Level(s) criteria for Level 1: Design Concept (1 point)

Identify the relevant design concepts of the project and answer yes or no on the corresponding checklist (see below) for each of the design concepts that have been addressed and provide a brief description of the measures or decision taken for each one. At least two of the design concepts must be addressed.
Life Cycle Design Concept Addressed? (yes/no) How has it been incorporated into the building design concept?
1. Efficient building shape and form
2. Optimized NZEB construction
3.Optimised material utilization and circular value
4. Extending building and component service lives
5. Design for adaptability
6. Design for deconstruction
Path 2: Fulfill the Level(s) criteria for Level 2 (3 points)

Conduct a life cycle assessment according to the Level(s) framework based on the building design. At least two impact categories must be reported in addition to GWP, according to LEED requirements. Do not report Module B6: Operational energy use.

For the reporting of impact categories, select global warming potential (greenhouse gases), in kg CO2e; and at least two of the following impact categories for reduction:
  • depletion of the stratospheric ozone layer, in kg CFC-11e;
  • acidification of land and water sources, in moles H+ or kg SO2e;
  • eutrophication, in kg nitrogen eq or kg phosphate eq;
  • formation of tropospheric ozone, in kg NOx, kg O3 eq, or kg ethene
Path 3: Fulfill the Level(s) criteria for Level 3 (4 points)

Conduct a life cycle assessment of the project’s according to the Level(s) framework after completion of the building, including the actual materials procured and technical building systems installed. At least two impact categories must be reported in addition to GWP, according to LEED requirements. Do not report Module B6: Operational energy use.

For the reporting of impact categories, select global warming potential (greenhouse gases), in kg CO2e; and at least two of the following impact categories for reduction:
  • depletion of the stratospheric ozone layer, in kg CFC-11e;
  • acidification of land and water sources, in moles H+ or kg SO2e;
  • eutrophication, in kg nitrogen eq or kg phosphate eq;
  • formation of tropospheric ozone, in kg NOx, kg O3 eq, or kg ethene
For paths 2 and 3 listed above, the reference study period of the Life Cycle Assessment must be at least 50 years. The software utilized for the study must be compliant with Level(s) and LEED requirements. See all forum discussions about this credit »

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Frequently asked questions

What is the difference between LCA and LCCA? Our clients often ask for LCA when they really want Life-Cycle Cost Analysis.

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Is it possible to pursue the Whole-Building Life-Cycle Assessment option late in design?

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Addenda

4/21/2023 – Updated: 5/9/2023
Rating System Correction
Description of change:
Revise the Core and Shell point threshold to 1-5 points

Revise second sentence under Requirements to: "Achieve one or more of the following options below for a maximum of 5 points."

Remove "...BD+C, 2-6 points Core and Shell)" from Option 1 and Path 1 titles.

Remove the Core and Shell Points column from Table 1.

Revise the language between Option 1 and Option 2 to "AND/OR"
Campus Applicable
No
Internationally Applicable:
No
4/21/2023 – Updated: 5/9/2023
Reference Guide Correction
Description of change:
Edit 3rd and 4th paragraphs under Behind the Intent to read as:
"Credit Option 2 (formerly Option 4), Whole Building Life Cycle Assessment, is now available to projects that pursue building reuse strategies that also wish to conduct an WBLCA for the project. The total points available cannot exceed 5 points, though projects can earn one Exemplary Performance point if they achieve reuse and/or WBLCA points from Option 1 and 2 and exceed 5 points in combination.

Credit Option 2 now has an entry pathway that rewards the effort to conduct a whole building life-cycle assessment without having to demonstrate specific impact reductions. Further, an incremental second point..."

Under Step by Step Guidance, Option 2, edit the 3rd sub-bullet to read: 'o Use Stage: Include at least one module from B1-B5 (structural materials without expected impacts from use, maintenance, repair or replacement over the building life are allowed to be excluded). " and add a following main bullet: " If the project site boundary includes detached ancillary structures, such as parking structures or outbuildings, those structures must be included in the WBLCA calculations."

Under Further Explanation, Option 2, add the following as the third sentence in the second paragraph: "Include structural materials from any detached or ancillary buildings in the WBLCA." and delete each of the Core and Shell point values in the three bullets.

Under Life-cycle impact measure or indicators section, revise second sentence to read as: "Reporting of impact category results: Report impacts in units of “per square foot” or “per square meter”, rounded to the nearest 10-4 for all six impact categories."

Add the following as a third bullet to Exemplary Performance:
" Achieve more than 5 points from a combination of Option 1 and Option 2. "
Campus Applicable
No
Internationally Applicable:
No
11/9/2020 – Updated: 3/1/2021
Rating System Correction
Description of change:
1.Modify point allocations for rating system versions as follows:
BD+C
1-6 points
This credit applies to
• BD+C: New Construction (1-5 points)
• BD+C: Core & Shell (1-6 points)
• BD+C: Schools (1-5 points)
• BD+C: Retail (1-5 points)
• BD+C: Data Centers (1-5 points)
• BD+C: Warehouses & Distribution Centers (1-5 points)
• BD+C: Hospitality (1-5 points)
• BD+C: Healthcare (1-5 points)

2. Re-title Option 1 as Building and Material Reuse (1-5 points BD+C, 2-6 points Core and Shell)

a. Remove current language under Option 1 (for Historic building reuse, Option 2- Renovation of abandoned or blighted building and Option 3: Building and material reuse)
b. Add the following description under Option 1: Building and Material Reuse:

"Maintain the existing building structure, envelope, and interior nonstructural elements. Reused or salvaged materials from off site that are incorporated into the building can also contribute to the credit calculations. However, reuse materials contributing toward this credit may not contribute toward MR Credit Material Disclosure and Optimization – Sourcing of Raw Materials.

Historic, abandoned or blighted buildings: Portions of buildings deemed structurally unsound or hazardous can be excluded from the credit calculations.

Path 1 and 2 reward projects that reuse structural and/or nonstructural elements based on the project completed floor area. Path 1 and 2 can be combined for points.


Path 1: Maintain Existing Structural Elements: Walls, Floors, Roofs, and Envelope (1-5 points BD+C, 2-6 points Core & Shell):

Maintain the existing building structure (including floor and roof decking) and envelope (the exterior skin and framing, excluding window assemblies and nonstructural roofing materials). Calculate reuse based on the project completed floor area according to Table 1. (Insert Table 1, Path 1 Points for reuse of building structural elements based on completed floor area)

AND/OR

Path 2: Maintain Interior Nonstructural Elements (1 point)

Use existing interior nonstructural elements (e.g. interior walls, doors, floor coverings and ceiling systems) for at least 30% of the project completed floor area, including additions. Delete remaining description underneath.

3. Re-title Option 4 as Option 2. Whole Building Life Cycle Assessment and modify first paragraph as follows:

OR
Option 2. Whole-Building Life-Cycle Assessment (1-4 points)

For new construction (buildings or portions of buildings), conduct a cradle-to-grave life-cycle assessment of the project’s structure and enclosure and select one or more of the following paths below to earn up to 4 points.

In the fifth paragraph under Option 2, delete "building" from the first sentence.

4. In the seventh paragraph under Option 2, add 'Baseline assumptions must be based on standard design and material selection for the project location and building type' after the line "The service life of the baseline and proposed buildings..."

5. Delete Healthcare only requirements
Campus Applicable
No
Internationally Applicable:
No
2/1/2021 – Updated: 2/5/2021
Reference Guide Correction
Description of change:
Under Option 1: Building and Material Use, revise fourth paragraph to read as "... elements within the existing building prior to construction or renovation."

Under Equation 3, delete "-hazardous materials area" from the denominator.
Campus Applicable
No
Internationally Applicable:
No
2/1/2021 – Updated: 2/5/2021
Rating System Correction
Description of change:
Under Option 1 and Path 1, delete both instances of "completed floor"
Under Path 1, revise last sentence to read as "Calculate reuse of the existing project area according to Table 1.

Revise Table 1 title to "Path 1 Points for reuse of existing building structural elements"
In Table 1, column 1 header, replace 'floor' with 'project'

Under Path 2, revise to read as "... for at least 30% of the entire completed building, including additions."
Campus Applicable
No
Internationally Applicable:
No
11/9/2020 – Updated: 11/30/2020
Reference Guide Correction
Description of change:
1.Under Beta Update:
Delete "Under In response to public comments and project team inquiries," from first sentence.
Revise third sentence to read as: "Further, if buildings or building elements cannot be re-used significantly, changes to the lifecycle analysis option of the credit encourage projects to conduct whole building life cycle assessment as an integral design component for many more buildings.

Revise the first three sentences in the second paragraph to read as:
"Former LEED v4 credit Option 1 (Historic Building reuse) and Option 2 (Renovation of Abandoned and Blighted Building) have been combined into Option 1 for v4.1. The former Credit Option 3 (Building and Material Reuse) now is replaced with a consolidated option 1 and includes two pathways for calculating building reuse. These changes consolidate the calculation methodology for all types of reuse and restore the LEED v2009 credit pathways (MR c1.1: Building reuse – maintain existing walls, floors and roofs; and MR c1.2: Building reuse – maintain interior nonstructural elements) that provided simpler, more prescriptive calculations.

Revise first sentence in third Paragraph to read: "Credit Option 2 (formerly Option 4), Whole Building Life Cycle Assessment, now has ..."

Revise last sentence in third paragraph to read: "Finally, to greater reward embodied carbon reductions through reuse, project teams can now earn up to four points in Credit Option 4 by incorporating building element reuse and/or salvaged ..."

2. Under Step by Step Guidance, revise Option 3 to Option 1.

Revise language to read as:'"New general guidance for v4.1 applicable to Paths 1 and 2:
Identify non-structural and structural elements of the existing space (e.g. walls, floors, roofs, doors, floor coverings, ceiling systems, etc.) that can be retained separately and in combination to select best pathway/approach for re-use (Path 1 or Path 2). Include elements reused onsite and/or salvaged from offsite as part of the reuse calculations.

Projects that incorporate part of an existing building but do not meet the requirements for this credit may apply the reused portion toward the achievement of MR Credit Sourcing of Raw Materials. To apply the reused portion for the Sourcing of Raw Material credit, determine the cost of each material. This cost will be the actual cost paid or, if the material came from on-site, the replacement value. The replacement value can be determined by pricing a comparable material in the local market; exclude labor and shipping. If a project team receives a discount from a vendor, the replacement value should reflect the discounted price as opposed to the list value. When the actual cost paid for the reused or salvaged material is below the cost of an equivalent new item, use the higher value (actual cost) cost of the new equivalent item in the calculations. When the cost to reclaim an item found on-site is less than the cost of an equivalent new item, use the cost of the new item (or replacement cost).

3. revise Option 4 to Option 2. and delete "Step 1" from first sentence.

At the end of the paragraph that starts: "Ensure that the scope of the analysis..." add "with the following clarifications:
 The system boundary of the analysis must include a cradle to grave scope (modules A-D). However, some gaps in sub-modules may exist due to the materials or dataset chosen and design optimizations attempted for the project. Gaps in sub-modules are allowed so long as the system boundary in total encompasses a cradle-to-grave assessment. The required modules for a compliant whole building life-cycle analysis include:
o Product stage: include modules A1-A3.
o Construction process: include at least module A4.
o Use Stage: Include at least one module from B1-B5.
o End of life stage: Include at least one module from C1-C4.
 For projects demonstrating impact reductions compared to a baseline: The LCA software or tool used for the baseline and proposed design must be the same, with the same modules and impact categories evaluated.
 Note that LCA software or tools must have ISO-14044-compliant data sets and conform to ISO 21931-2017 and/or EN 15978:2011 and their data must meet the requirements of ISO 21930-2017 and EN 15804. Typically, the software tool providers will document they meet these criteria in the LCA output report.

Additional Guidance for Whole Building LCA Tool Providers:

The system boundary of a whole building LCA must include modules A-D as defined in ISO 21930 and EN 15804. LCA tools must have ISO-14044-compliant data sets and conform to ISO 21931-2017 and/or EN 15978:2011. Further, the underlying data must meet the requirements of ISO 21930-2017 and EN 15804.
 If LCI data is not available for certain products, LCA tools can incorporate product EPD data into their ISO 14044 compliant LCI datasets as long as:
o The EPD has not expired.
o The EPD scenarios are representative of contemporary technologies and/or practice, and are relevant to the project location.
o The EPD data reports all indicators and system boundary information required by WBLCA tools.
o The EPD or LCA clearly indicates which product (manufacturer and product name) or geographical region it reflects in compared to industrywide results of a material available in the tool.

4. Under further explanation, delete and replace with:

Option 1: Building and Material Reuse
The v4 calculation of formerly credit Option 3. Building and Material Reuse in LEED v4 reference guide has been changed. Steps 1 and 3 have been removed. Step 2 (Reuse off-site materials) remains in effect.

The LEED v4 Building and Material Reuse concept and calculation for “surface area and layers of reuse” is no longer utilized. Instead, project teams will calculate reuse as follows below for Path 1 and Path 2.

Path 1 Calculations: Maintain Existing Structural Elements: Walls, Floors, Roofs and Envelope

The reuse calculation is based on the surface areas of major existing structural and envelope elements per equation 3. Structural support elements such as columns and beams are considered part of the larger surfaces they support, so they are not quantified separately.

Prepare a spreadsheet listing all envelope and structural elements within the building. Quantify each item, listing the square footage of both the existing area and the retained area. Determine the percentage of existing elements that are retained by dividing the square footage of the total retained materials area by the square footage of the total existing materials area. Include any salvaged or reused materials that were sourced off-site and integrated into the project as part of the reused area in the calculations.

Take measurements as if preparing a bid for construction of a building. For structural floors and roof decking, calculate the square footage of each component. For existing exterior walls and existing walls adjoining other buildings or additions, calculate the square footage of the exterior wall only and subtract the area of exterior windows and exterior doors from both the existing and the reused area tallies. For interior structural walls (e.g., shear walls), calculate the square footage of one side of the existing wall element. Table 1 provides an example of the calculations for Path 1.

Table 1. Sample Building Structure and Envelope Reuse Calculation for Path 1.
(Insert Table here)

Exclude the following items from this calculation: nonstructural roofing material, window assemblies, structural and envelope materials that are deemed structurally unsound, hazardous materials, and materials that pose a contamination risk to building occupants.

Equation 3. Percentage of existing building reuse – maintain existing structural elements:

Existing building reuse = (area reused on-site+area reused from off-site)/(existing building area-hazardous materails area) x 100

Path 2 Calculations: Maintain Interior Nonstructural Elements

This pathway focuses on reuse of interior, nonstructural elements and compares the retained and reused elements with the total completed area of interior elements. It is not necessary to calculate the total area of existing interior nonstructural elements prior to demolition. Include any salvaged or reused materials that were sourced off-site and integrated into the project as part of the reused area in the calculations.

Take measurements as if preparing a bid for flooring, ceiling, or painting:
• Finished ceilings and flooring areas (tile, carpeting, etc.). Use square footage or square meters to determine area.
• Interior nonstructural walls. Determine the finished area between floor and ceiling and count both sides.
• Exterior structural and party walls. If the interior finishes (e.g., drywall and plaster) have been reused, count only one side.
• Interior doors. Count surface area once.
• Interior casework. Calculate the visible surface area of the assembly.

Include items that have been saved but may have been relocated, such as full-height demountable walls and doors that were rehung. Also include reused items purchased or sourced off-site from other buildings or projects, such as from salvage yards or donations.

Fixed items, such as nonstructural walls and doors, are included in this credit and count toward the percentage of reuse when they perform the same function (e.g., doors reused as doors). If materials are used for another purpose (e.g., doors made into tables), they can count toward the achievement of MR Credit: Sourcing of Raw Materials, but they cannot count toward both credits.

Table 2 illustrates a spreadsheet for determining credit compliance. The total area of all new and existing building materials (following construction) is determined. The total area of only the existing and reused components is then entered. The sum of the existing materials is then divided by the sum of the total building materials to obtain the overall percentage of retained components. Since the overall percentage of reused nonstructural interior materials exceeds 30% of the total area of all nonstructural interior building materials, the project earns 1 point.

Table 2. Sample Interior Nonstructural Element Reuse Calculation for Path 2.
Determine the percentage of existing elements that are retained by dividing the total area of all retained interior nonstructural elements by the total area of interior nonstructural elements following Equation 4.

Equation 4: Percentage of existing building reuse – maintain interior nonstructural elements:

Interior nonstructural reuse = ((area of retained interior nonstructural elements+area of elements reused from offsite))/(total area of interior nonstructural elements) x 100

Projects that incorporate part of an existing building for reuse but do not meet the requirements for Path 2 may apply the reused portion toward the achievement of MR Credit Construction and Demolition Waste Management. To do so, determine an approximate weight or volume for existing building elements and count them as waste diversion in the credit calculations.

7. Revise Option 4 to: "Option 2 (formerly Option 4): Whole Building Life Cycle Assessment
Refer to Option 4 in the LEED v4 reference guide with the following modifications and additions:

Add the following language under the paragraph that starts "This option now has four thresholds..."

"Developing an appropriate baseline building is necessary for a compliant WBLCA to show reductions in global warming potential and other impacts. Product and material environmental characteristics in the baseline building must reflect standard design practices and typical material selection choices for the project location and building type. For instance, assuming zero-percent recycled content in some metal products or concrete mixes does not reflect typical practice in North America. Project teams should look to common project types in the region and review industry resources in order to develop accurate baselines for claimed impact reductions. In documenting the credit, project teams will need to include a description of why the baseline structure and enclosure systems represent typical construction for the project, location, and building type."

Revise the next paragraph to read as: "Within Option 2, choose Path 1 (whole building life cycle analysis of the project) and/or Path 2, 3 or 4 (comparative whole-building life cycle analysis) as outlined in credit requirements. Note that for Path 1, project teams must complete a standard Whole Building Life Cycle Assessment (WBLCA) of the proposed design and report the impact categories in a WBLCA report, however there are no thresholds for reductions necessary to earn this point."

Revise the three bullet points to read as:
 2 points (3 points Core & Shell) – demonstrated impact reduction of at least 5% in Global Warming Potential and at least 2 other impact categories.
 3 points (4 points Core & Shell) – demonstrated impact reduction of at least 10% in Global Warming Potential and at least 2 other impact categories.
 4 points (5 points Core & Shell) – demonstrated impact reduction of 20% in Global Warming Potential and at least 10% in at least 2 other impact categories. This option must also incorporate reuse and/or salvaged materials ..."


Modify the following section under Required Documentation as follows:
Documentation requirements for former Option 1 (historic building reuse) and Option 2 (renovation of abandoned or blighted building) are now included under the restructured Option 1: Building and Material Reuse.

Documentation requirement for Option 1 Building and Material Reuse:
 Path 1: Structural and nonstructural reused elements table and calculations
 Path 2: Interior nonstructural reused elements table and calculations
Documentation requirement for Option 2, Whole Building LCA:
 WBLCA report for structure and enclosure of building
Documentation requirement for Option 2, Whole Building LCA Path 2, 3 and 4:
 WBLCA report that includes description of LCA assumptions, scope and analysis process for baseline building and proposed building, life cycle impact assessment summary showing outputs of proposed building with percent change from baseline building for all impact categories, and a narrative indicating which path was pursued and how reductions were achieved.

Add a new section on Exemplary Performance:
Exemplary Performance
 Option 1: Path 1: Reuse 90% of the building
 Option 2: Achieve Path 4 and show 40% reduction in GWP.
































































Campus Applicable
No
Internationally Applicable:
No
7/25/2019 – Updated: 7/29/2019
Rating System Correction
Description of change:
Change Path 2a to Path 2 and change Path 2b to Path 3.
Campus Applicable
No
Internationally Applicable:
No
See all forum discussions about this credit »

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Associate, Built Ecology

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Intent

To encourage adaptive reuse and optimize the environmental performance of products and materials.

Requirements

Demonstrate reduced environmental effects during initial project decision-making by reusing existing building resources or demonstrating a reduction in materials use through life-cycle assessment.

Achieve one or more of the following options below for a maximum of 5 points.

Option 1. Building and Material Reuse (1-5 points)

Maintain the existing building structure, envelope, and interior nonstructural elements. Reused or salvaged materials from off site that are incorporated into the building can also contribute to the credit calculations. However, reuse materials contributing toward this credit may not contribute toward MR credit- Sourcing of Raw Materials.

Historic, abandoned or blighted buildings: Portions of buildings deemed structurally unsound or hazardous can be excluded from the credit calculations.

Path 1 and 2 reward projects that reuse structural and/or nonstructural elements based on the project area. Path 1 and 2 can be combined for points.


Path 1: Maintain Existing Structural Elements: Walls, Floors, Roofs, and Envelope (1-5 points)

Maintain the existing building structure (including floor and roof decking) and envelope (the exterior skin and framing, excluding window assemblies and nonstructural roofing materials). Calculate reuse of the existing project area according to Table 1.

Table 1. Path 1 Points for reuse of existing building structural elements.

Percent of existing walls, floors and roof reuse by project area Points BD+C
15% 1
30% 2
45% 3
60% 4
75% 5
AND/OR

Path 2: Maintain Interior Non structural Elements (1 point)

Use existing interior nonstructural elements (e.g. interior walls, doors, floor coverings and ceiling systems) for at least 30% of the entire completed building, including additions.

AND/OR
Option 2. Whole-Building Life-Cycle Assessment (1-4 points)

For new construction (buildings or portions of buildings), conduct a cradle-to-grave life-cycle assessment of the project’s structure and enclosure and select one or more of the following paths below to earn up to 4 points:

Path 1: Conduct a life cycle assessment of the project’s structure and enclosure (1 point).

Path 2: Conduct a life cycle assessment of the project’s structure and enclosure that demonstrates a minimum of 5% reduction, compared with a baseline building in at least three of the six impact categories listed below, one of which must be global warming potential (2 points).

Path 3: Conduct a life cycle assessment of the project’s structure and enclosure that demonstrates a minimum of 10% reduction, compared with a baseline building, in at least three of the six impact categories listed below, one of which must be global warming potential (3 points).

Path 4: Meet requirements of Path 3 and incorporate reuse and/or salvage materials into the project’s structure and enclosure for the proposed design. Demonstrate reductions compared with a baseline building of at least 20% reduction for global warming potential and demonstrate at least 10% reduction in two additional impact categories listed below (4 points).

For Paths 2, 3 and 4 listed above, no impact category assessed as part of the life-cycle assessment may increase by more than 5% compared with the baseline building. Include a narrative of how the life cycle assessment was conducted and if applicable for paths 2, 3 and 4 what changes were made to proposed buildings in order to achieve the related impact reductions.

The baseline and proposed buildings must be of comparable size, function, orientation, and operating energy performance as defined in EA Prerequisite Minimum Energy Performance. The service life of the baseline and proposed buildings must be the same and at least 60 years to fully account for maintenance and replacement. Baseline assumptions must be based on standard design and material selection for the project location and building type. Use the same life-cycle assessment software tools and data sets to evaluate both the baseline building and the proposed building, and report all listed impact categories. Data sets must be compliant with ISO 14044.

Select at least three of the following impact categories for reduction:
  • global warming potential (greenhouse gases), in kg CO2e;
  • depletion of the stratospheric ozone layer, in kg CFC-11e;
  • acidification of land and water sources, in moles H+ or kg SO2e;
  • eutrophication, in kg nitrogen eq or kg phosphate eq;
  • formation of tropospheric ozone, in kg NOx, kg O3 eq, or kg ethene; and
  • depletion of nonrenewable energy resources, in MJ using CML / depletion of fossil fuels in TRACI.
Europe ACP: Option 4 Whole Building Life-Cycle Assessment

For European projects, EN standard 15978 may be used as framework for the Life-Cycle-Assessment instead of ISO 14044 for this credit. Where implementation of EN 15978 conflicts with any of requirements of this credit, the credit requirements prevail, including the life-cycle stages required and treatment of EPD data (See Further Explanation - Incorporation of EPD data in WBLCA Tools). Note that the CML indicators are acceptable per the Further Explanation section of the Reference Guide language of this credit. Projects will still need to meet the individual requirements of the pathway chosen for this credit option.

Further Explanation - Incorporation of EPD data in WBLCA Tools: Combining EPD impacts with WBLCA results shall follow the best practice guidance outlined in Athena Guide to Whole Building LCA in Green Building Programs which stipulates that EPD results may only be combined provided the EPD:

  • Has not expired;
  • EPD scenarios should be representative of contemporary technologies and/or practice, and the project location;
  • Reports all indicators and system boundary information modules required by the WBLCA tool;
  • Characterizes the impact categories reported according to the same LCA methodology as the WBLCA tool;
  • Can be applied to the study period of the assessment;
  • Clearly indicates which product (including manufacturer and product name) or geographical region it reflects in comparison to the industry-wide weighted average results of a material or fuel already available in the tool.
Additionally, comparability shall be ensured in accordance with Section 5 of the BRE Briefing Paper "Assessing the environmental impacts of construction – understanding European Standards and their implications."
Europe ACP: Whole-Building LCA according to the Level(s) framework


The approach for a Europe ACP is for projects which fulfil the Level(s) criteria, to earn points in the LEED MR credit: Building Life-Cycle Impact Reduction accordingly.

For new construction (buildings or portions of buildings), select one or more of the following paths below to earn up to 4 points:

Path 1: Fulfill the Level(s) criteria for Level 1: Design Concept (1 point)

Identify the relevant design concepts of the project and answer yes or no on the corresponding checklist (see below) for each of the design concepts that have been addressed and provide a brief description of the measures or decision taken for each one. At least two of the design concepts must be addressed.
Life Cycle Design Concept Addressed? (yes/no) How has it been incorporated into the building design concept?
1. Efficient building shape and form
2. Optimized NZEB construction
3.Optimised material utilization and circular value
4. Extending building and component service lives
5. Design for adaptability
6. Design for deconstruction
Path 2: Fulfill the Level(s) criteria for Level 2 (3 points)

Conduct a life cycle assessment according to the Level(s) framework based on the building design. At least two impact categories must be reported in addition to GWP, according to LEED requirements. Do not report Module B6: Operational energy use.

For the reporting of impact categories, select global warming potential (greenhouse gases), in kg CO2e; and at least two of the following impact categories for reduction:
  • depletion of the stratospheric ozone layer, in kg CFC-11e;
  • acidification of land and water sources, in moles H+ or kg SO2e;
  • eutrophication, in kg nitrogen eq or kg phosphate eq;
  • formation of tropospheric ozone, in kg NOx, kg O3 eq, or kg ethene
Path 3: Fulfill the Level(s) criteria for Level 3 (4 points)

Conduct a life cycle assessment of the project’s according to the Level(s) framework after completion of the building, including the actual materials procured and technical building systems installed. At least two impact categories must be reported in addition to GWP, according to LEED requirements. Do not report Module B6: Operational energy use.

For the reporting of impact categories, select global warming potential (greenhouse gases), in kg CO2e; and at least two of the following impact categories for reduction:
  • depletion of the stratospheric ozone layer, in kg CFC-11e;
  • acidification of land and water sources, in moles H+ or kg SO2e;
  • eutrophication, in kg nitrogen eq or kg phosphate eq;
  • formation of tropospheric ozone, in kg NOx, kg O3 eq, or kg ethene
For paths 2 and 3 listed above, the reference study period of the Life Cycle Assessment must be at least 50 years. The software utilized for the study must be compliant with Level(s) and LEED requirements.

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4/21/2023 – Updated: 5/9/2023
Rating System Correction
Description of change:
Revise the Core and Shell point threshold to 1-5 points

Revise second sentence under Requirements to: "Achieve one or more of the following options below for a maximum of 5 points."

Remove "...BD+C, 2-6 points Core and Shell)" from Option 1 and Path 1 titles.

Remove the Core and Shell Points column from Table 1.

Revise the language between Option 1 and Option 2 to "AND/OR"
Campus Applicable
No
Internationally Applicable:
No
4/21/2023 – Updated: 5/9/2023
Reference Guide Correction
Description of change:
Edit 3rd and 4th paragraphs under Behind the Intent to read as:
"Credit Option 2 (formerly Option 4), Whole Building Life Cycle Assessment, is now available to projects that pursue building reuse strategies that also wish to conduct an WBLCA for the project. The total points available cannot exceed 5 points, though projects can earn one Exemplary Performance point if they achieve reuse and/or WBLCA points from Option 1 and 2 and exceed 5 points in combination.

Credit Option 2 now has an entry pathway that rewards the effort to conduct a whole building life-cycle assessment without having to demonstrate specific impact reductions. Further, an incremental second point..."

Under Step by Step Guidance, Option 2, edit the 3rd sub-bullet to read: 'o Use Stage: Include at least one module from B1-B5 (structural materials without expected impacts from use, maintenance, repair or replacement over the building life are allowed to be excluded). " and add a following main bullet: " If the project site boundary includes detached ancillary structures, such as parking structures or outbuildings, those structures must be included in the WBLCA calculations."

Under Further Explanation, Option 2, add the following as the third sentence in the second paragraph: "Include structural materials from any detached or ancillary buildings in the WBLCA." and delete each of the Core and Shell point values in the three bullets.

Under Life-cycle impact measure or indicators section, revise second sentence to read as: "Reporting of impact category results: Report impacts in units of “per square foot” or “per square meter”, rounded to the nearest 10-4 for all six impact categories."

Add the following as a third bullet to Exemplary Performance:
" Achieve more than 5 points from a combination of Option 1 and Option 2. "
Campus Applicable
No
Internationally Applicable:
No
11/9/2020 – Updated: 3/1/2021
Rating System Correction
Description of change:
1.Modify point allocations for rating system versions as follows:
BD+C
1-6 points
This credit applies to
• BD+C: New Construction (1-5 points)
• BD+C: Core & Shell (1-6 points)
• BD+C: Schools (1-5 points)
• BD+C: Retail (1-5 points)
• BD+C: Data Centers (1-5 points)
• BD+C: Warehouses & Distribution Centers (1-5 points)
• BD+C: Hospitality (1-5 points)
• BD+C: Healthcare (1-5 points)

2. Re-title Option 1 as Building and Material Reuse (1-5 points BD+C, 2-6 points Core and Shell)

a. Remove current language under Option 1 (for Historic building reuse, Option 2- Renovation of abandoned or blighted building and Option 3: Building and material reuse)
b. Add the following description under Option 1: Building and Material Reuse:

"Maintain the existing building structure, envelope, and interior nonstructural elements. Reused or salvaged materials from off site that are incorporated into the building can also contribute to the credit calculations. However, reuse materials contributing toward this credit may not contribute toward MR Credit Material Disclosure and Optimization – Sourcing of Raw Materials.

Historic, abandoned or blighted buildings: Portions of buildings deemed structurally unsound or hazardous can be excluded from the credit calculations.

Path 1 and 2 reward projects that reuse structural and/or nonstructural elements based on the project completed floor area. Path 1 and 2 can be combined for points.


Path 1: Maintain Existing Structural Elements: Walls, Floors, Roofs, and Envelope (1-5 points BD+C, 2-6 points Core & Shell):

Maintain the existing building structure (including floor and roof decking) and envelope (the exterior skin and framing, excluding window assemblies and nonstructural roofing materials). Calculate reuse based on the project completed floor area according to Table 1. (Insert Table 1, Path 1 Points for reuse of building structural elements based on completed floor area)

AND/OR

Path 2: Maintain Interior Nonstructural Elements (1 point)

Use existing interior nonstructural elements (e.g. interior walls, doors, floor coverings and ceiling systems) for at least 30% of the project completed floor area, including additions. Delete remaining description underneath.

3. Re-title Option 4 as Option 2. Whole Building Life Cycle Assessment and modify first paragraph as follows:

OR
Option 2. Whole-Building Life-Cycle Assessment (1-4 points)

For new construction (buildings or portions of buildings), conduct a cradle-to-grave life-cycle assessment of the project’s structure and enclosure and select one or more of the following paths below to earn up to 4 points.

In the fifth paragraph under Option 2, delete "building" from the first sentence.

4. In the seventh paragraph under Option 2, add 'Baseline assumptions must be based on standard design and material selection for the project location and building type' after the line "The service life of the baseline and proposed buildings..."

5. Delete Healthcare only requirements
Campus Applicable
No
Internationally Applicable:
No
2/1/2021 – Updated: 2/5/2021
Reference Guide Correction
Description of change:
Under Option 1: Building and Material Use, revise fourth paragraph to read as "... elements within the existing building prior to construction or renovation."

Under Equation 3, delete "-hazardous materials area" from the denominator.
Campus Applicable
No
Internationally Applicable:
No
2/1/2021 – Updated: 2/5/2021
Rating System Correction
Description of change:
Under Option 1 and Path 1, delete both instances of "completed floor"
Under Path 1, revise last sentence to read as "Calculate reuse of the existing project area according to Table 1.

Revise Table 1 title to "Path 1 Points for reuse of existing building structural elements"
In Table 1, column 1 header, replace 'floor' with 'project'

Under Path 2, revise to read as "... for at least 30% of the entire completed building, including additions."
Campus Applicable
No
Internationally Applicable:
No
11/9/2020 – Updated: 11/30/2020
Reference Guide Correction
Description of change:
1.Under Beta Update:
Delete "Under In response to public comments and project team inquiries," from first sentence.
Revise third sentence to read as: "Further, if buildings or building elements cannot be re-used significantly, changes to the lifecycle analysis option of the credit encourage projects to conduct whole building life cycle assessment as an integral design component for many more buildings.

Revise the first three sentences in the second paragraph to read as:
"Former LEED v4 credit Option 1 (Historic Building reuse) and Option 2 (Renovation of Abandoned and Blighted Building) have been combined into Option 1 for v4.1. The former Credit Option 3 (Building and Material Reuse) now is replaced with a consolidated option 1 and includes two pathways for calculating building reuse. These changes consolidate the calculation methodology for all types of reuse and restore the LEED v2009 credit pathways (MR c1.1: Building reuse – maintain existing walls, floors and roofs; and MR c1.2: Building reuse – maintain interior nonstructural elements) that provided simpler, more prescriptive calculations.

Revise first sentence in third Paragraph to read: "Credit Option 2 (formerly Option 4), Whole Building Life Cycle Assessment, now has ..."

Revise last sentence in third paragraph to read: "Finally, to greater reward embodied carbon reductions through reuse, project teams can now earn up to four points in Credit Option 4 by incorporating building element reuse and/or salvaged ..."

2. Under Step by Step Guidance, revise Option 3 to Option 1.

Revise language to read as:'"New general guidance for v4.1 applicable to Paths 1 and 2:
Identify non-structural and structural elements of the existing space (e.g. walls, floors, roofs, doors, floor coverings, ceiling systems, etc.) that can be retained separately and in combination to select best pathway/approach for re-use (Path 1 or Path 2). Include elements reused onsite and/or salvaged from offsite as part of the reuse calculations.

Projects that incorporate part of an existing building but do not meet the requirements for this credit may apply the reused portion toward the achievement of MR Credit Sourcing of Raw Materials. To apply the reused portion for the Sourcing of Raw Material credit, determine the cost of each material. This cost will be the actual cost paid or, if the material came from on-site, the replacement value. The replacement value can be determined by pricing a comparable material in the local market; exclude labor and shipping. If a project team receives a discount from a vendor, the replacement value should reflect the discounted price as opposed to the list value. When the actual cost paid for the reused or salvaged material is below the cost of an equivalent new item, use the higher value (actual cost) cost of the new equivalent item in the calculations. When the cost to reclaim an item found on-site is less than the cost of an equivalent new item, use the cost of the new item (or replacement cost).

3. revise Option 4 to Option 2. and delete "Step 1" from first sentence.

At the end of the paragraph that starts: "Ensure that the scope of the analysis..." add "with the following clarifications:
 The system boundary of the analysis must include a cradle to grave scope (modules A-D). However, some gaps in sub-modules may exist due to the materials or dataset chosen and design optimizations attempted for the project. Gaps in sub-modules are allowed so long as the system boundary in total encompasses a cradle-to-grave assessment. The required modules for a compliant whole building life-cycle analysis include:
o Product stage: include modules A1-A3.
o Construction process: include at least module A4.
o Use Stage: Include at least one module from B1-B5.
o End of life stage: Include at least one module from C1-C4.
 For projects demonstrating impact reductions compared to a baseline: The LCA software or tool used for the baseline and proposed design must be the same, with the same modules and impact categories evaluated.
 Note that LCA software or tools must have ISO-14044-compliant data sets and conform to ISO 21931-2017 and/or EN 15978:2011 and their data must meet the requirements of ISO 21930-2017 and EN 15804. Typically, the software tool providers will document they meet these criteria in the LCA output report.

Additional Guidance for Whole Building LCA Tool Providers:

The system boundary of a whole building LCA must include modules A-D as defined in ISO 21930 and EN 15804. LCA tools must have ISO-14044-compliant data sets and conform to ISO 21931-2017 and/or EN 15978:2011. Further, the underlying data must meet the requirements of ISO 21930-2017 and EN 15804.
 If LCI data is not available for certain products, LCA tools can incorporate product EPD data into their ISO 14044 compliant LCI datasets as long as:
o The EPD has not expired.
o The EPD scenarios are representative of contemporary technologies and/or practice, and are relevant to the project location.
o The EPD data reports all indicators and system boundary information required by WBLCA tools.
o The EPD or LCA clearly indicates which product (manufacturer and product name) or geographical region it reflects in compared to industrywide results of a material available in the tool.

4. Under further explanation, delete and replace with:

Option 1: Building and Material Reuse
The v4 calculation of formerly credit Option 3. Building and Material Reuse in LEED v4 reference guide has been changed. Steps 1 and 3 have been removed. Step 2 (Reuse off-site materials) remains in effect.

The LEED v4 Building and Material Reuse concept and calculation for “surface area and layers of reuse” is no longer utilized. Instead, project teams will calculate reuse as follows below for Path 1 and Path 2.

Path 1 Calculations: Maintain Existing Structural Elements: Walls, Floors, Roofs and Envelope

The reuse calculation is based on the surface areas of major existing structural and envelope elements per equation 3. Structural support elements such as columns and beams are considered part of the larger surfaces they support, so they are not quantified separately.

Prepare a spreadsheet listing all envelope and structural elements within the building. Quantify each item, listing the square footage of both the existing area and the retained area. Determine the percentage of existing elements that are retained by dividing the square footage of the total retained materials area by the square footage of the total existing materials area. Include any salvaged or reused materials that were sourced off-site and integrated into the project as part of the reused area in the calculations.

Take measurements as if preparing a bid for construction of a building. For structural floors and roof decking, calculate the square footage of each component. For existing exterior walls and existing walls adjoining other buildings or additions, calculate the square footage of the exterior wall only and subtract the area of exterior windows and exterior doors from both the existing and the reused area tallies. For interior structural walls (e.g., shear walls), calculate the square footage of one side of the existing wall element. Table 1 provides an example of the calculations for Path 1.

Table 1. Sample Building Structure and Envelope Reuse Calculation for Path 1.
(Insert Table here)

Exclude the following items from this calculation: nonstructural roofing material, window assemblies, structural and envelope materials that are deemed structurally unsound, hazardous materials, and materials that pose a contamination risk to building occupants.

Equation 3. Percentage of existing building reuse – maintain existing structural elements:

Existing building reuse = (area reused on-site+area reused from off-site)/(existing building area-hazardous materails area) x 100

Path 2 Calculations: Maintain Interior Nonstructural Elements

This pathway focuses on reuse of interior, nonstructural elements and compares the retained and reused elements with the total completed area of interior elements. It is not necessary to calculate the total area of existing interior nonstructural elements prior to demolition. Include any salvaged or reused materials that were sourced off-site and integrated into the project as part of the reused area in the calculations.

Take measurements as if preparing a bid for flooring, ceiling, or painting:
• Finished ceilings and flooring areas (tile, carpeting, etc.). Use square footage or square meters to determine area.
• Interior nonstructural walls. Determine the finished area between floor and ceiling and count both sides.
• Exterior structural and party walls. If the interior finishes (e.g., drywall and plaster) have been reused, count only one side.
• Interior doors. Count surface area once.
• Interior casework. Calculate the visible surface area of the assembly.

Include items that have been saved but may have been relocated, such as full-height demountable walls and doors that were rehung. Also include reused items purchased or sourced off-site from other buildings or projects, such as from salvage yards or donations.

Fixed items, such as nonstructural walls and doors, are included in this credit and count toward the percentage of reuse when they perform the same function (e.g., doors reused as doors). If materials are used for another purpose (e.g., doors made into tables), they can count toward the achievement of MR Credit: Sourcing of Raw Materials, but they cannot count toward both credits.

Table 2 illustrates a spreadsheet for determining credit compliance. The total area of all new and existing building materials (following construction) is determined. The total area of only the existing and reused components is then entered. The sum of the existing materials is then divided by the sum of the total building materials to obtain the overall percentage of retained components. Since the overall percentage of reused nonstructural interior materials exceeds 30% of the total area of all nonstructural interior building materials, the project earns 1 point.

Table 2. Sample Interior Nonstructural Element Reuse Calculation for Path 2.
Determine the percentage of existing elements that are retained by dividing the total area of all retained interior nonstructural elements by the total area of interior nonstructural elements following Equation 4.

Equation 4: Percentage of existing building reuse – maintain interior nonstructural elements:

Interior nonstructural reuse = ((area of retained interior nonstructural elements+area of elements reused from offsite))/(total area of interior nonstructural elements) x 100

Projects that incorporate part of an existing building for reuse but do not meet the requirements for Path 2 may apply the reused portion toward the achievement of MR Credit Construction and Demolition Waste Management. To do so, determine an approximate weight or volume for existing building elements and count them as waste diversion in the credit calculations.

7. Revise Option 4 to: "Option 2 (formerly Option 4): Whole Building Life Cycle Assessment
Refer to Option 4 in the LEED v4 reference guide with the following modifications and additions:

Add the following language under the paragraph that starts "This option now has four thresholds..."

"Developing an appropriate baseline building is necessary for a compliant WBLCA to show reductions in global warming potential and other impacts. Product and material environmental characteristics in the baseline building must reflect standard design practices and typical material selection choices for the project location and building type. For instance, assuming zero-percent recycled content in some metal products or concrete mixes does not reflect typical practice in North America. Project teams should look to common project types in the region and review industry resources in order to develop accurate baselines for claimed impact reductions. In documenting the credit, project teams will need to include a description of why the baseline structure and enclosure systems represent typical construction for the project, location, and building type."

Revise the next paragraph to read as: "Within Option 2, choose Path 1 (whole building life cycle analysis of the project) and/or Path 2, 3 or 4 (comparative whole-building life cycle analysis) as outlined in credit requirements. Note that for Path 1, project teams must complete a standard Whole Building Life Cycle Assessment (WBLCA) of the proposed design and report the impact categories in a WBLCA report, however there are no thresholds for reductions necessary to earn this point."

Revise the three bullet points to read as:
 2 points (3 points Core & Shell) – demonstrated impact reduction of at least 5% in Global Warming Potential and at least 2 other impact categories.
 3 points (4 points Core & Shell) – demonstrated impact reduction of at least 10% in Global Warming Potential and at least 2 other impact categories.
 4 points (5 points Core & Shell) – demonstrated impact reduction of 20% in Global Warming Potential and at least 10% in at least 2 other impact categories. This option must also incorporate reuse and/or salvaged materials ..."


Modify the following section under Required Documentation as follows:
Documentation requirements for former Option 1 (historic building reuse) and Option 2 (renovation of abandoned or blighted building) are now included under the restructured Option 1: Building and Material Reuse.

Documentation requirement for Option 1 Building and Material Reuse:
 Path 1: Structural and nonstructural reused elements table and calculations
 Path 2: Interior nonstructural reused elements table and calculations
Documentation requirement for Option 2, Whole Building LCA:
 WBLCA report for structure and enclosure of building
Documentation requirement for Option 2, Whole Building LCA Path 2, 3 and 4:
 WBLCA report that includes description of LCA assumptions, scope and analysis process for baseline building and proposed building, life cycle impact assessment summary showing outputs of proposed building with percent change from baseline building for all impact categories, and a narrative indicating which path was pursued and how reductions were achieved.

Add a new section on Exemplary Performance:
Exemplary Performance
 Option 1: Path 1: Reuse 90% of the building
 Option 2: Achieve Path 4 and show 40% reduction in GWP.
































































Campus Applicable
No
Internationally Applicable:
No
7/25/2019 – Updated: 7/29/2019
Rating System Correction
Description of change:
Change Path 2a to Path 2 and change Path 2b to Path 3.
Campus Applicable
No
Internationally Applicable:
No

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WSP USA
Associate, Built Ecology

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