Find & Compare Materials

The Find & Compare Materials feature allows a user to search within the growing list of product categories using a search tree. Product and Industry EPDs are stored in a graph database format and are also accessible via the EC3 openEPD API.

Most categories, such as Concrete, contain further subcategories (e.g., Ready Mix, Shotcrete, etc.) that can be accessed by clicking the “+” sign for a category.

There are several icons associated with product categories, detailed below:


“Pilot”: Indicates a product category that is further developed than “draft” but still needs categorization work, industry-specific uncertainty factors, and/or additional EPD data to be considered final. Pilot categories are only visible to pilot users, typically volunteers at sponsor organizations who agree to provide feedback on parts of the tool while they are in development, and prior to public release.

“Accessory”: Indicates that a product category is used in conjunction with another product category but is not included in the other product category’s statistics. This product category should be accounted for separately if more precise results are important.

“Manufacturing Input”: Indicates that the material product category is an input to this product category. Its statistics will not be included in the parent product category.

“Foreign”: This subcategory uses a different declared unit than its parent. As a result, EPDs within this product category are not included in product category’s statistics.

Searching EPDs

Within each material category, a user can search by material-specific performance characteristics, location, and custom items such as manufacturer name and product description. Clicking the search button will return a list of all Environmental Product Declarations (EPDs) within the database that meet the user’s search criteria. This list can then be filtered and sorted by such criteria as manufacturer name, plant name, product description, and kgCO2e.

By default, the list of EPDs yielded by a search will include both Industry EPDs and Product EPDs, as available. Each Industry EPD is weighted as 20 product EPDs, with a gaussian (normal) distribution around the industry average. (see Uncertainty & Statisticsfor more details) The user can continue to narrow this list by entering further search terms for any EPD attribute. The EPD Type term under “more…” lets you search only product EPDs, only Industry EPDs, or both.

The result of the search is displayed as a box-and-whisker chart of the embodied GWP per declared unit. In most cases it will show quite a large variation in the GWP of different brands of the same product. This difference is typically real, though there are also differences in measurement methodology or data sources that impact comparability. A good general rule is not to rely on the top or bottom values, but to try to reach the ‘achievable target’, while assuming that the ‘conservative estimate’ is what will occur if no special effort is taken to get a low-carbon product.

Above the Statistics bar are search terms, which affect the statistics and the whisker chart. Below the Statistics bar and above the list of results are filters that help users find Selected EPDs in the list, but do NOT affect the statistics. Below the search results are controls to page through the results, typically returned 25 at a time.

Comparing EPDs

Comparing manufacturers or plants will bring up a figure with plots showing the overall box and whisker plot for EPDs within the search and individual plots for each manufacturer or plant.

Comparing products will expand the box and whisker plot under the “kgCO2e embodied per” unit heading to include the selected products. Like comparing manufacturers or plants, the plot will show the overall spread for EPDs and where the selected EPDs fall.

Viewing a Digital EPD

Shown on the webpage is another box and whisker diagram that has an arrow indicating how the comparison (80% confidence) estimate of the EPD’s GWP compares to the range of GWP values within the product’s parent product category. This can be used to inform decision making as it shows users where the selected EPD’s GWP falls within the possible GWP range for that product category.

Editing EPDs

User Account and Organization types and EPD editing privileges.

User typeEditing privileges


Edit all fields for all EPDs. Only select users and Building Transparency staff and have this level of access.


Edit all fields for EPDs with errors. This access level is restricted to close partners who have a data curation agreement with Building Transparency.

Program Operator (with Write or Manage permission)

Edit all fields for EPDs under that Program Operator.

Manufacturer (with Write or Manage permission)

Edit product information and plant information fields for EPDs where the manufacturer or its subsidiaries are the owner of the EPD

Industry Association (with Write or Manage permissions)

Edit product information and member information fields for Industry EPDs where the association is the owner of the EPD

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