Calculating Generic Material Data

2050 Materials Generic Materials DB Methodology

Introduction

Currently, there is a growing concern about the impact of human activities on the environment. One of the major factors contributing to this environmental impact is the construction industry. The construction industry is responsible for a significant amount of carbon emissions, as well as other negative environmental consequences. That is why it is important to create a generic materials carbon database that can be used to identify the environmental impact of construction products.

The process of computing a generic materials carbon database involves the statistical analysis of thousands of EPDs. These EPDs are classified according to the main material type and product category. The statistical analysis involves the removal of outliers, calculating median values for each value of the EPD, and then manual check by experts in-house.

The resulting database provides a representative range of carbon emissions for each material and product category, which can be used as a reference for environmental impact assessments in the construction industry.

Why calculate generic material data?

The construction industry is responsible for a significant amount of carbon emissions and other environmental impacts. As a result, there is a growing concern about the impact of human activities on the environment. In response, Environmental Product Declarations (EPDs) have become increasingly important in the industry. These declarations provide a detailed analysis of the environmental impact of a product throughout its life cycle, from raw materials extraction to end-of-life disposal.

However, not all construction products have product-specific EPDs available. In such cases, a generic materials carbon database becomes essential for calculating Whole Life-cycle assessments (WLCAs) for buildings. This database provides an estimate of the environmental impact of a construction product based on its material type and product category.

Additionally, while product-specific EPDs are becoming more common, generic material data is still useful in identifying erroneous data or misleading assumptions by EPD modellers. For example, it may identify products that have a very low carbon footprint compared to similar products, indicating that there may be errors in the data or assumptions. It can also be used to flag assumptions that may not be accurate across all products in a category, such as assumptions about transportation distances or manufacturing processes.

We acknowledge that as more manufacturers create product-specific EPDs, the importance of generic material data may decrease. However, it will continue to serve an important role in the construction industry, both in filling gaps in the availability of product-specific EPDs, as well as in providing a benchmark for comparing the environmental impact of products within a category.

Step-by-step Methodology

1. Data Collection: The first step in creating the generic materials carbon database involves collecting EPDs from various sources such as the ECO Platform~~,~~ and EC3, as well as automatic and manual scraping of manufacturer’s websites.

2. Data digitization and standardization: When all product specific EPDs are collected the 2050 Materials team runs OCR scripts to extract as much information as possible from non-digitalized EPDs. Additionally, a team of researchers creates mapping files to structure the data, as it is often in fragmented formats and languages. This step is crucial to ensure the data is consistent and can be analyzed easily. Standardizing the data allows for seamless integration into other tools through the API.

3. Data Classification: The collected data is then classified according to the “NRM1 Group Elements” and “NRM1 Elements”. Additionally, the 2050 Materials team extracts the main material type from EPDs, and classifies each EPD into a specific product category (e.g. Tiles). This classification helps to standardize and organize the data, making it easier to analyze and identify trends and patterns Moreover, it allows for the identification of data outliers that may require further scrutiny.

4. Statistical Analysis:

   1. Grouping: In order to compute the generic material data, the data is grouped according to a combination of “Product Type” and “Material Type”, and in some cases the manufacturing location (country). This enables the computation of generic material data for a specific product with a main material type (e.g. Ceramic Tiles) or sometimes a specific product with a main material type in a specific manufacturing country (e.g. Ceramic Tiles, UK).

   2. Outlier Removal: The next step involves the removal of outliers from the EPD data. Outliers are data points that are significantly different from the rest of the data. These outliers can skew the results of the analysis and make it difficult to identify any trends or patterns. The team removes any datapoints in outside of the 5th-95th percentile of EPD data within each combination

   3. Median Calculation: After removing the outliers, we calculate the median values for each value of the EPD. This is done to ensure that the values are representative of the data set as a whole. The median is a more robust measure of central tendency than the mean, which is why it is preferred in this analysis.

   4. Buffer: The median value is multiplied by a “buffer” in order to provide a conservative estimate and to avoid any false estimations. The buffer used is 15% (i.e. the median computed in the step above is multiplied by 1.15)

   5. Manual Check: The final step is the process of manually checked values by experts in-house. This is important to ensure that the values are accurate and representative of the EPD data. The experts check the values to ensure that they are consistent with the trends and patterns identified in the data, as well as comparable to other available generic material databases (e.g. ICE DB V3).

Technical Clarifications & Assumptions

• Declared unit / Functional Unit - The declared unit in Life-cycle assessments (LCA) is the functional unit that is used to compare the environmental performance of different products. It represents the function of the product, such as the amount of energy produced or the distance traveled, rather than the physical quantity of the product. For this database, 2050 Materials always refers to the declared unit provided in each EPD, but stores all available data which helps transform that unit into other ones (e.g. Density, Specific Density, Weight per declared unit)

• Biogenic Carbon - For the generic materials database, we exclude EPDs which report biogenic carbon combined with fossil carbon, and only use the ones which have the 2 types split. Therefore, biogenic carbon is reported as a separate column, and there should not be any biogenic carbon (i.e. negative values) expected under the “fossil-carbon” fields.

• Lifecycle stages considered - We consider the following lifecycle stages:

  • A1-A3

  • A5 A4 is excluded as it is project-location dependent

  • B1-B5

  • C1, C3, C4 C2 is excluded as it is project-location dependent

• Errors in the base data - Our methodology is subject to errors that can arise from inaccurate EPD modelling and/or false data which may skew some data points. While we strive to minimize these errors, the 2050 Materials team cannot completely eliminate them. Nevertheless, we are continuously conducting quality assurance checks and updating the underlying EPD information to ensure the accuracy of our database.

Datapoints calculated

For this process, the following datapoints are computed in 2050 Material’s database:

• Total Fossil Carbon [kg CO2e/FU] (stages reported)

• Total Biogenic Carbon [kg CO2e/FU] (stages reported)

• Fossil Carbon (A1-A3) [kg CO2e/FU]

• Fossil Carbon (A5) [kg CO2e/FU]

• Fossil Carbon (B1-B5) [kg CO2e/FU]

• Fossil Carbon (C1, C3, C4) [kg CO2e/FU]

• Freshwater use (A1-A3) [liters / FU]

• Recycled Content [%] - Calculated based on the Secondary Material (SM, in kg) divided by the mass of the declared unit (Mass_per_declared_unit, in kg) in the LCA input table for stages A1-A3

• Recyclable Content [%] - Calculated based on the Materials for Recycling (in kg) divided by the mass of the declared unit (Mass_per_declared_unit, in kg) in the LCA input table for stages A1-A3

• Re-use Potential [%] - Calculated based on the Materials for Reuse (in kg) divided by the mass of the declared unit (Mass_per_declared_unit, in kg) in the LCA input table for stages A1-A3

• Energy Recovery Possibility [%] - Calculated based on the Materials for Energy Recovery (in kg) divided by the mass of the declared unit (Mass_per_declared_unit, in kg) in the LCA input table for stages A1-A3

• Ozone Depletion Potential (A1-A3) [mg CFC-11eq]

• Density [kg/m3]

• Specific Density [kg/m2]

Calculation Example

Generic Material Data for Ceramic Tiles in UK

1. Grouping:

The following table shows the EPD data for Ceramic Tiles in the UK, grouped by "Product Type" and "Material Type".

Product Type	Manufacturing Country	Material Type	Carbon (a1-a3)
Tiles	UK	Ceramic	1.10 kg CO2e/kg
Tiles	UK	Ceramic	1.87 kg CO2e/kg
Tiles	UK	Ceramic	0.01 kg CO2e/kg
Tiles	UK	Ceramic	1.23 kg CO2e/kg
Tiles	UK	Ceramic	1.45 kg CO2e/kg
Tiles	UK	Ceramic	2.22 kg CO2e/kg
Tiles	UK	Ceramic	0.9 kg CO2e/kg

1. Outlier Removal:

   The data points outside of the 5th-95th percentile of EPD data within each combination are removed. In this case, the data point with the value of 2.22 kg CO2e/kg is an outlier and will be removed.

2. Median Calculation:

The median values for each EPD value are calculated, as shown in the table below:

Product Type	Manufacturing Country	Material Type	Carbon (a1-a3)
Tiles	UK	Ceramic	1.10 kg CO2e/kg
Tiles	UK	Ceramic	1.87 kg CO2e/kg
Tiles	UK	Ceramic	0.01 kg CO2e/kg
Tiles	UK	Ceramic	1.23 kg CO2e/kg
Tiles	UK	Ceramic	1.45 kg CO2e/kg
Tiles	UK	Ceramic	0.9 kg CO2e/kg
Median			1.23 kg CO2e/kg

1. Buffer:

The median value for Carbon (a1-a3) is multiplied by a buffer of 15%, resulting in a value of 1.4145 kg CO2e/kg.

1. Manual Check:

The final step involves manual checking by experts in-house. The value of 1.4145 kg CO2e/kg is checked by experts to ensure that it is accurate and representative of the EPD data for Ceramic Tiles in the UK. The experts also compare this value to other available generic material databases (e.g. ICE DB V3) to ensure its comparability.

Conclusion

In conclusion, the process of computing a generic materials carbon database involves the collection, classification, outlier removal, median calculation, and manual check of EPD data. This process ensures that the values in the database are accurate and representative of the EPD data. The database can be used to identify the environmental impact of construction products and help in making more sustainable choices in the construction industry. The development of this database is an important step towards a more sustainable future.

Additional Queries

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