What is this calculation tool about?
This guide will walk you through how to do a life cycle assessment for LEED v4.1 ID+C, MR Credit, Option 3: Building Interiors Life Cycle Assessment using One Click LCA.
The purpose of the LEED v4.1 ID+C credit, MR Credit, Option 3 is to conduct a life cycle assessment of the project’s structure and interior fit-out. There are up to 3 credits available depending upon which path you would like to pursue.
Within Option 3, there are 3 paths you can choose from, which earn different amounts of credits:
Path 1: Conduct a life cycle assessment of the project’s interior (1 point)
Path 2: Meet the requirements of Path 1 and conduct a life cycle assessment of the project’s interior design compared against a baseline interiors project (2 points).
Path 3: Meet the requirements of Path 2 and incorporate building reuse and/or salvage materials into the project’s scope of work. Demonstrate reductions compared with the interiors project baseline of at least 20% for global warming potential and demonstrate at least 10% reduction in two additional impact categories listed below (3 points).
For Paths 2 and 3: The baseline and proposed interior projects must be of comparable size, function and operating energy performance as defined in EA Prerequisite Minimum Energy Performance. The service life of the baseline and proposed building interior must be the same to fully account for maintenance and replacement and must be a minimum of 20 years. Baseline assumptions must be based on standard design and material selection for the project location and building type. Data sets must be compliant with ISO 14044.
For Path 3, no more than one impact category assessed as part of the life-cycle assessment may increase compared with the baseline interiors project. Include a narrative of how the life cycle assessment was conducted and what changes were made to proposed interior design in order to achieve the related impact reductions.
Select at least three of the following impact categories for reduction, one of which must be GWP:
- 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
This guidance applies for the following One Click LCA tools:
- LCA for LEED, International (using CML impact assessment methodology)
- LCA for LEED, US (using TRACI impact assessment methodology)
- LCA for LEED, Canada (using TRACI impact assessment methodology)
What is included in the scope?
This credit requires you to conduct a life-cycle assessment of the project’s entire scope of work, including structure and enclosure (if any), ceiling, wall, flooring, interior partition assemblies including acoustic insulation, metal framing, finishes, coatings and furnishings.
The materials and products could include but are not limited to: flooring, walls and wall systems, ceiling and ceiling systems glass and glass systems, furniture, lighting, doors, door frames/door hardware, interior finishes, nonstructural partitions, piping, plumbing, fixtures, ductwork, cabling, and fire suppression systems.
How to complete an assessment in One Click LCA
- Create a new design
- Fill in the building materials query of the design either manually or by import.
Add all of the materials required by the calculation scope (see above).
You are allowed to use either average data, manufacturer-specific EPDs (recommended) or similar products from another manufacturer. Use net quantities (amounts of material installed in the building); the on-site losses of materials would be included in module A5 but that is excluded from the calculation by credit specification.
This information will be used to calculate the raw material harvesting, transportation and manufacturing impacts in A1-A3.
- Once the correct materials and quantities are provided, set the transportation distances from material manufacturer to the project site and transport methods.
The default transportation distances can be set up from the project’s LCA parameters page. If they are chosen, any material will use the average distance unless a more specific one is given in the query. This information will be used to calculate the impacts of material transportation in A4.
- Finally, check the material service life.
This information will be used to calculate the material replacements for B1-B5.
Material service life means how long each material will last in your building. If the service life is less than 60 years the material will have to be replaced. From an environmental impacts point of view, this means additional emissions from the production of new material that is needed to replace the old one.
Each of the materials in One Click LCA database has a default service life. However, as the exposure conditions of the materials may vary, it may be good to check that the service life matches the condition of your building. It is especially important to check the external wall and roof material service lives’ as the weather conditions may vary greatly between areas.
- Adjust the localisation of each material as needed (expert feature). This information will be used to compensate for any material data chosen from another area to match your project’s local material manufacturing conditions.
- Fill in the building area query. This information will be used as a divider for the results in a separate result row and it will help you to understand how the results compare to other projects. Gross floor area is required.
After you have done one calculation you can create as many additional designs you wish either by copying the first one or by creating a new empty one. This can be used for creating a baseline or to create additional 'what if' scenarios. To copy a design click its name and choose 'Copy'. To create a new one press the '+ Add a design' button on the project main page.
Once the Baseline design is completed, create a copy of it and name it 'Proposed design'.
Requirements for the baseline
To make sure that the baseline and proposed models can be accurately compared, the following aspects must be kept the same in both the baseline and the proposed building:
- LCA scope requirements. The functional unit and system boundary must be identical for the baseline and proposed buildings. Basically, this means that you’ll have to use the same calculation tool for both.
- Size. The gross floor area of the baseline and proposed buildings must be the same. The two designs can have different massing, provided the gross area is the same.
- Function. The baseline and proposed buildings must serve the same programmatic function. If the project is a mixed-use residential building with retail on the first floor, the baseline building must have the same program, but the elements can be in different locations in the building. If the project is a hospital with stringent air quality and humidity control, both the baseline and the proposed cases must meet those functional requirements.
- Orientation. The orientation—the directional exposure—of the baseline and proposed buildings must be the same, but the shape may differ. Orientation must be the same because exposure to the sun affects solar heat gain within the building and will skew LCA results for energy performance.
- Location. Both the baseline and the proposed buildings must be located in the same ASHRAE 90.1–2010 climate zone and assumed to be on the same site.
- Operating energy performance. The baseline and proposed buildings must meet EA Prerequisite Minimum Energy Performance by adhering to the requirements of ASHRAE 90.1–2010, Appendix G, Opaque Assemblies, Vertical Fenestration, Skylights, and Roof Solar Reflectance and Thermal Emittance sections because comparing an energy-efficient proposed building with an underperforming baseline building will skew the results. Increasing wall mass or insulation unnecessarily in the baseline building to show dematerialization in the proposed building is not acceptable. Energy modelling for either building is not required for this credit.
Other portions of the baseline building may be modified from the basic ASHRAE 90.1 requirements to capture the LCA goals of the project team.
As a summary:
You are allowed to
You are not allowed to
Optimize and reduce the mass of your actual building (from any studied part of the building)
Increase wall mass or insulation unnecessarily for the baseline building to show dematerialization
Change the structures and design of the building, including stud spacing, floor-to-ceiling heights, changes in the use of beams and pillars
Use a different area for the baseline building and actual design (specified as gross area)
Identify opportunities to make design changes to use lower -emissions materials or specify the use of specific products with quantified life-cycle impacts
Omit required parts of the envelope and structure: footings and foundations, structural wall assembly (from cladding to interior finishes), structural floors and ceilings (not including finishes), roof assemblies
Include additional elements, such as interior nonstructural walls or finishes (no extra credit)
Include excavation, site development, parking lots or building technologies and systems