Athena has the free resources you need for earning LCA credits in green programs and reporting embodied carbon.

ID=1821 :: post_name=lca-credits :: post_title=LCA Credits :: post_status=publish :: post_type=page :: post_category=Array

Green building programs in North America recognize the value of LCA in sustainable design.

Life cycle assessment (LCA) provisions and embodied carbon requirements in various green building programs, policy, and code require access to data and simplified tools like those provided for free by the Athena Institute. This page briefly explains what we understand about current LCA provisions in these programs (warning: this page may be out of date given how quickly this landscape is changing).

LCA addresses two big gaps in traditional approaches to sustainable design. First, LCA substitutes meaningful environmental impact metrics for much of the current guesswork. Second, LCA accounts for the embodied environmental burdens of construction. Embodied impacts are typically ignored, even though they constitute the vast majority of environmental burden for the first portion of a building’s life and need to be reduced if we’re serious about climate change mitigation.

Several green building programs in North America have incentives for designers to use LCA to guide measurable environmental improvements in new construction. Many of the programs use a similar “reference building” comparative approach: teams earn compliance by showing that the final building design (core and shell) has lower LCA impacts than a self-defined reference building – typically, this would be an earlier design iteration. Conducting LCA during the design process creates an initial performance benchmark to beat, helping inform decisions as they evolve from conceptual design through design development.

LEED:
The MR credit, “Building Life-Cycle Impact Reduction” (option 4) was new for version 4 and evolved several times. In LEED v4, the base credit is worth three points, an additional point is available for exemplary performance, and in many parts of Canada another point is available for regional priority. Compliance requires showing improvement over a reference building. In LEED v4.1, simply conducting an LCA earns one point. Showing improvement over a reference building earns between two and four points. In LEED v5, the previous approach (multiple LCA measures) is gone and replaced with two credits that only address embodied carbon (GWP). Credit MRp2 “Quantify and Assess Embodied Carbon” is mandatory. Applicants must report A1-A3 GWP for each material in the structure, enclosure, and hardscape systems, and additionally must identify the top three sources of GWP and what strategies have been considered to reduce their impacts. Credit MRc2 “Reduce Embodied Carbon” is worth up to six points and has a few options. Option 1 is similar to the original v4 credit, with reporting for six LCA metrics, however, only GWP targets are required to be met, and points can be earned for simply meeting the baseline GWP (rather than a required improvement). Applicants compare wbLCA results to a baseline, report results for six LCA metrics, and receive points based on how much reduction in GWP compared to the baseline (up to six points). Option 2 has two variations of an EPD approach, where EPDs are used to show that materials meet or exceed baselines (up to three points). Option 3 requires that construction site energy be tracked (up to two points). Options 2 and 3 can be added on to Option 1.

Green Globes:
In the New Construction 2024 version, Materials section, three points are available for simply conducting LCA and reporting at least five LCA metrics. An additional one to seven points are available for showing a reduction in GWP compared to a baseline (more points for more reduction). An additional five to 16 points are available for showing a cumulative reduction across three LCA measures, one of which must be GWP (more points for more reduction).

IgCC:
The 2024 International Green Construction Code, Chapter 9, offers an LCA performance path alternative to prescriptive material requirements. Compliance requires showing improvement over a reference building: minimum 10% reduction in each of two LCA metrics, one of which must be GWP, or 5% reduction in three LCA metrics, one of which must be GWP. Results must be reported for nine LCA metrics. Structural material quantities must be signed off by a professional. The LCA must be third-party critically reviewed.

CALGreen:
The California Green Building Standards Code (CALGreen) has mandatory embodied carbon requirements. Nonresidential commercial building projects over 100,000 square feet and school building projects over 50,000 square feet are required to comply with one of three pathways:

1. Building Reuse: Reuse at least 45% of an existing structure and exterior. When reuse is combined with new construction, the total addition area using this pathway is limited to double the area of the existing structure.

2. Performance: Complete a whole building lifecycle assessment demonstrating 10% lower embodied carbon emission than a baseline project design.

3. Prescriptive: Document environmental product declarations (EPDs) for listed materials (steel, glass, mineral wool, concrete) that are on average lower than a specified threshold of global warming potential.

Living Building Challenge:
In LBC v4.1, under the Energy Petal, projects must show a 20% reduction in embodied carbon over a reference building. In addition, projects that are pursuing “net positive carbon” must offset all A1-A5 embodied carbon, either through purchase of a carbon offset and/or through “on-site carbon sequestering materials.” These projects must also aim for an embodied carbon threshold of no higher than 350 kg CO2e per square meter of floor area.

CaGBC Zero Carbon Building program:
The Canada Green Building Council has two zero carbon building standards: one for during design, and one for post-occupancy (performance standard – requires annual verification). In the Design Standard v4, project teams must conduct LCA and show that GWP per square metre of floor area is less than a given cap or show a 10% reduction in GWP over a baseline building. For on-going performance certification, an embodied carbon offset must be purchased.

City of Vancouver:
Vancouver has its own building code (Vancouver Building By-law), which puts an embodied carbon cap on most buildings other than small residential. In addition, Vancouver requires that projects applying for a rezoning must show that they are “on track” to meet the embodied carbon conditions in the building by-law.

City of Toronto:
The Toronto Green Standard v4 has embodied carbon caps on most buildings other than single family homes. The caps are currently voluntary for everything except city-owned projects.

ILFI Zero Carbon program:
In v1.1, project teams must conduct LCA, show a 20% reduction in embodied carbon over a baseline building, aim to meet a cap of 350 kg CO2e/m2 of floor area, and purchase an offset for embodied carbon.

Need help getting the credits?
The Athena Impact Estimator for Buildings (IE4B) is a free software tool that is key to earning these credits. This software was developed specifically for North American construction-industry professionals and requires no special expertise to use. The IE4B’s inherent LCA methodology, cradle-to-grave system boundary and inventory datasets make compliance with these green program requirements easy. To get started: