Living Building Challenge and Zero Carbon

The best-suited tool for covering the Living Building Challenge standard is to use the Net Zero Carbon tool but other carbon tools can be used too

The International Living Building Institute (ILFI) has prepared two guidance standards - the Living Building Challenge and Zero Carbon to respond to the demand for reducing carbon emissions in the built environment. Both, the Living Building Challenge and Zero Carbon promote the design of high-performance, climate-positive buildings that account for their total carbon impacts by reducing and offsetting both operational and embodied carbon. This article follows version 4.0 of the standards.

In the Living Building Challenge, imperative 08 states the following requirements for the buildings to be aligned with the standard:

Embodied Carbon Reductions:

• New and Existing buildings must demonstrate a twenty percent reduction in the embodied carbon of primary materials compared to an equivalent baseline.
• All projects must select interior materials with lower than industry baseline embodied carbon emissions for product categories for which data is readily available.

Carbon offsets:

• For all projects, approved carbon offsets must be procured to cover the embodied carbon emissions related to any new materials utilized in the project.

EPD:

• Product-specific embodied carbon data should be sourced from Environmental Product Declarations (EPDs)

In Zero Carbon, buildings must meet the following requirements to be aligned with the standard:

Embodied Carbon Reductions:

• New and Existing buildings must demonstrate a ten percent reduction in the embodied carbon of primary materials compared to an equivalent baseline.
• The total embodied carbon (primary and interior) of the project building must not exceed 500kg CO2e/m2

Carbon offsets:

• One hundred percent of the embodied carbon emissions impacts associated with the construction and materials of the project must be disclosed and offset through the use of on-site carbon-sequestering materials or by a one-time purchase of carbon offsets from an ILFI-approved source

EPD:

• Product-specific embodied carbon data should be sourced from Environmental Product Declarations (EPDs)

The scope of calculations for Living Building Challenge and Zero Carbon includes accounting for embodied carbon emissions for the life cycle stages A1-A5 (production stage). Moreover, one should include the primary materials for foundations, frames, slabs, envelopes, and roofing as well as interior materials for ceilings, floors, wall finishes, and partitions in the scope of the calculation.

One does NOT need to include building technology, furniture or site works in the calculations; these are optional.

The type of analysis is comparative, and one should create a baseline and a proposed building design. The baseline building must have the same 1. Size, gross floor area 2. Programmatic function and 3. Energy performance as the proposed building.

Enter your construction materials

Fill in the building materials query of the design either manually or by import. Add all of your materials. 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 the 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.

Wastage percentage is the amount of material going to waste during the construction phase and the results are accounted for in construction phase A5.

Optionally, you can adjust the localization 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.

Enter your site operations (A5)

For construction site input manually project-specific information in questions 2-5

Fill in the Offsets & Net Zero Definition Query.

First, set your Net Zero definition. By default, all options have ‘Yes’ selected to be included in your Net Zero definition but you have the option to select ‘No’ from the dropdown if you do not wish to include a particular category. Categories that you exclude are not included in the calculation on the results page. 

Next, add any carbon offsets you have purchased in the Verified Carbon Offsets section, choosing to attribute the offsets for up to completion (A1-A5) of the building (or for the whole life (B1-C4).

Results

Once your mandatory queries have been filled, you can view your results section, where results are split into Upfront Carbon (A1-A5), Operating Carbon (B1-B7), and End of Life (C-D). Please note that only the upfront carbon results are relevant for these ILFI standards.

You can see any emissions that have been subtracted through biogenic carbon, materials reuse, exported energy, and carbon offsets, and then view your final net carbon result in the bottom right corner.

Further steps

Copy a design and create an alternative, either from the proposed building or from the baseline building using alternative materials to gain the required reductions.

Strategies to reduce embodied carbon emissions include: