> For the complete documentation index, see [llms.txt](https://docs.buildingtransparency.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.buildingtransparency.org/ec3/material-categories/painting-and-coating.md).

# Painting & Coating

## How Paint EPDs Are Reported and Compared

For paints, the Product Category Rules (PCR) define the functional unit as **1 m² of coated surface over a 60-year building reference life**. To meet this requirement, paint EPDs include the impacts of all repaintings needed within that 60-year period, based on the product’s design life (e.g., 15 years) or market life (e.g., 5 years).

As a result, the reported life cycle results in paint EPDs already accounting for multiple applications of paint. However, these impacts are often allocated to the product stage (A1–A3) rather than being distributed into the use stage (B modules).

To make the data comparable, EC3 **normalizes the reported results back to one single application of paint per 1 m² of surface area**. This ensures that products with different assumed lifetimes can be compared on a consistent basis, regardless of how many repaintings were originally included in the EPD calculations.

The service life and frequency of repainting is absolutely relevant for the evaluation of the best paint product for the users' application, however, it should be considered as part of the B modules of the building assessment and with the specific use case and repainting requirements for the users project. EPDs provide a more general service life information than what needs to be considered in the context of a specific building project.


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