Embodied Carbon Optimiser Tools

A description of our methodology and protocols when developing the embodied carbon optimiser tools on the 2050 Materials platform.

Aim of the tool

The Embodied Carbon Optimizer is a visual tool developed by 2050 Materials. It provides a simplified LCA calculation for early design phases, allowing users to quickly compare either entire building typologies or building systems' climate impacts by customising standard assemblies per component.

The tool aims to be interactive, easing the translation of material choices into simplified constructive details while navigating dynamic environmental impact breakdowns (A1-A3 modules) displayed per material and system.

Additionally, for the building-level optimizer tools, a forward looking benchmarking metric called “Warming Potential” is calculated, aimed at helping designers and architects understand the contribution of their selection to global climate goals.

Data sources & Data collection

The data included in the Embodied Carbon tool comes from 2050 Materials' internal database, which is based on Environmental Product Declarations (EPD) from internal sources and external third parties.

The research process for collecting specific data on materials per building component responds to the following parameters: regionality, material type (source origin), building application, and product type (function). For more about the criteria for classifying material types and product types, check 2050 Materials Framework.

For buildings, the tool shows material choices for each large component of the building, based on the data collected.

For assemblies, the tool displays the material choices through a list of components determined by their function within the building assembly, as explained in Section 5 of this document. Each component item lists the most commonly used and manufactured products with a specific material type. Example: building assembly - Stone Facade; component - Exterior finish; component’s materials - granite, limestone, quartzite, sintered stone, slate.

In this section, we will refer generically to the corresponding material of a component as “materials”, hence, a manufactured product whose function within the building assembly and material is specified.

Selection of Materials

The steps to select the materials data included in the dropdowns of the different assembly components (exterior finish, insulation, etc.) are as follows:

Collection of EPDs

The number of EPDs per material collected for subsequent average data analysis depends on the number of products available in the database. The minimum number of EPDs from different manufacturers per material to be considered for data collection is 5.

  1. Products with less than 5 EPDs from different manufacturers: In the case of innovative and biobased materials, there could be less than 3 EPDs, which minimises the options to compare values. Hence, it is considered if it is relevant to include these material types in the selection dropdown. In certain cases, we may chose a single EPD as having representative data for that particular material, due to the absence of enough data to provide statistical averages.

  2. Products with more than 10 EPDs from different manufacturers: In this case, an internal statistical tool determines the average values. Reach out to us if you are interested in finding out more about our internal analytics tools.

  3. Analysis of average values

According to the previous criteria, the number of selected EPDs is used to calculate the average values corresponding to the environmental metrics (GWP and FW in A1-A3) per material. These average values are relevant to showing the user the standard values of the most common products manufactured.

Selection of EPDs

The final data selection comes from a specific EPD, as specific physical properties must be considered for calculating the final quantities of environmental impacts. Grammage, density, and thickness are key properties in this respect, and the environmental impacts are correlated to these physical properties. Hence, specific EPDs whose data is below the average values determined in the previous analysis are selected.

Physical Properties

The current Embodied Carbon Tool version only includes physical properties for insulation materials within the assemblies section. Specifically, we include thermal transmittance (U-value). According to a previous study of average values regarding physical properties and environmental metrics, a specific EPD of an insulation product is selected within the average ranges of similar materials.

  • Thermal conductivity (W/mK). This data from the EPD IS considered to calculate the specific U-value per material thickness of insulation materials with uniform properties. See section 3.5 about calculations, assumptions and exceptions.

  • Thickness. A preliminary study on the standard thickness of most common insulation materials currently available in the market is done. Three types of thicknesses are set within the average values usually manufactured to allow the user to compare the thermal performance of different materials easily.

Methodology

Life-Cycle Assessment

LCA is a methodology for assessing environmental impacts (including embodied carbon) associated with all the stages of a system's life cycle (whole building, construction material, building assembly, etc.). LCA considers all the steps that occur during each system's lifetime, from raw material extraction and manufacturing to distribution and usage and final disposal.

The current version of Embodied Carbon Tool shows a simplified LCA for phases A1-A3 according to EN15978 standard and EN 15804 standards. Further stages related to Construction, In Use or End of Life are not included as the tool is conceived for pre-design stage purposes that require high-level materiality assessments for assemblies (and buildings).

The modules A1-A3 correspond to the product stage or manufacturing stage (Cradle to Gate):

  • A1: Raw material extraction and processing, processing of secondary material input (e.g. recycling processes)

  • A2: Transport to the manufacturer

  • A3: Manufacturing

Specific Assumptions

  • All data is based on Environmental Product Declarations (EPD) covering the manufacturing stages (life cycle phases A1–A3). The quantities are based on 1 m2 of wall or roof surface area for each system, and 1 m2 of GIA (Gross Internal Area) for buildings.. Hence, quantities for each layer are calculated accordingly subject to the relevant FUs (functional units).

  • This tool is fully customizable with importing capabilities for Bills of Quantities, alternative sector targets and bespoke product databases for real facade and roof scenarios.

  • The Warming Potential is a forward-looking metric designed to show the temperature alignment of the selected design based on the required reductions as described in the 2021 UNEP Gap report.

  • The Embodied Carbon Optimizer tool was created using open-source environmental impact data and average schedules for envelope assemblies.

  • The Embodied Carbon Optimizer tool’s simplified LCA is suitable for early design stages, so a complete LCA for the whole building is highly recommended for later stages. The values should be calculated on a specific project basis and not relied upon for their project, as they're generic and must be used for indicative purposes only at the earliest design stage possible.

Environmental metrics

The results provide data about specific environmental metrics for A1-A3 phases per m2 of assembly or GIA.:

  • Carbon footprint (GWP -fossil). Greenhouse gas emissions related to raw material extraction (A1), transport to the manufacturing location (A2) and production (A3). Unit: kg CO2e/m2 assembly.

  • Sequestered Carbon (GWP -biogenic). Amount of CO2 that is sequestered or captured and stored within construction materials and components, reducing their contribution to greenhouse gas emissions. Unit: kg biogenic CO2e/m2 assembly.

  • Water footprint. Fresh water used in the manufacturing stages A1-A3 for each material chosen in the assembly. Unit: m3 freshwater /m2 assembly.

Physical properties

The component “Insulation” is displayed as a list of insulation materials with an average thermal transmittance value.

  • Thermal transmittance (U-value). Rate of heat transfer through a material. It indicates how well a material insulates against heat flow. A lower U-value indicates better insulation properties, meaning less heat is transmitted through the material.

Calculations: impacts, physical properties and quantities

Functional Unit (FU) and quantification criteria

All the environmental impacts are converted to the functional unit of m2 and calculated based on 1m2 of surface area of assembly or 1m2 of GIA in the case of buildings.

Environmental metrics

  • GWP (Global Warming Potential) [kg CO2e]: measures how much a given mass of a greenhouse gas contributes to global warming over a specified time, usually 100 years, compared to carbon dioxide. It's a way to understand the effect of emissions from products or activities on the Earth's temperature. The higher the GWP, the more a substance warms the Earth compared to CO2 over that period.

  • FW (Freshwater use) [litres of fresh water]: quantifies the total amount of freshwater used or consumed in the production of a product. This metric is crucial for assessing a product's impact on water resources, reflecting both direct water use and indirect consumption along the supply chain. Lower FW values are better, indicating less strain on freshwater resources.

Performance metrics

Thermal transmittance (U-value)

The thermal transmittance of insulation materials is given as a reference and calculated as follows:

Formula: U= λ / d

U : U-value (thermal transmittance) in W/m²K.

λ : thermal conductivity of the material in W/mK.

d : is the thickness of the material in metres.

(*) This formula assumes a steady-state condition and uniform material properties.

  • Assumptions:

    • The calculation refers only to specific materials (insulation materials). Hence, Rsi and Rse aren’t considered as these factors refer to thermal transmittance calculations of the entire building assembly (external wall, roof, etc.) considering all the assembly layers.

  • Exceptions: composite materials

    • The U-value of insulation products that are composites (made of different materials), like sandwich panels or EIFS, corresponds to the specific value of the EPD when considering different thicknesses within the same product type. Due to the manufacturing complexity of these types of products, the aforementioned simplified formula cannot be applied as it assumes a steady-state condition and uniform material properties.

    • In this case, the data per product with a specific thickness has to be collected individually from EPDs by following the criteria in section 2.1. (1).

Rounding values criteria

During the calculation process of environmental metrics, two decimal places are considered for Global Warming Potential (kg CO2e/m2 assembly) and three decimals for Fresh Water (m3 freshwater /m2 assembly).

The rounding criteria are applied at the end of the calculations considering no decimals for the final value of Global Warming Potential and two decimals for Fresh Water.

Criteria for building applications and assembly types

The last version of the tool provides building applications for external walls and roofs. A research study is run for each building application to determine the most common and standardised building systems or assemblies grouped by “families” according to similar combinations of components or layers.

Families of external wall assemblies

Criteria for assembly components

Each system has been simplified into standardised components per function within the family of assemblies or systems as follows:

All External Wall Families

Warm Flat Roof

Inverted Roof

  1. Exterior finish support

  2. Insulation

  3. Construction foil

  4. Sheathing board

  5. Masonry inner leaf

  6. Stud framing

  7. Building board

  8. Plaster/render

  9. Interior finish

  1. Roof covering

  2. Separation foil (1)

  3. Waterproofing

  4. Separation foil (2)

  5. Insulation

  6. Vapour barrier

  7. Screed

  1. Roof covering

  2. Roof membrane

  3. Insulation

  4. Separation foil (1)

  5. Waterproofing

  6. Separation foil (2)

  7. Screed

Figure 2. Available assemblies’ families’ and related components in the tool.

The tool allows the selection of whether to include or exclude certain components depending on the assembly family. For example, separation foils in roof assemblies are optional, as including these components depends on their specific material and performance within the rest of the assembly's layers or components.

Criteria for constructive details’ configurations

This multiple-choice option for building materials is translated into various simplified constructive details by offering several assembly configurations per system (10 configurations for facade systems, 8 configurations for flat roof systems).

The function of creating different configurations doesn’t discriminate between the compatibility of materials within the specific assembly configuration selected.

Quality Assurance

The QA process is based on statistical analysis, which derives updated generic values from the internal product-specific database. According to these updates, the Embodied Carbon Tool data and functions are periodically updated approximately every 6 months.

For tutorials and steps on how to use the tool, please refer to our platform tutorials on Youtube

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