Environmental Product Declarations (EPDs) in the US Market
Written by James Westaway
As sustainability requirements continue to evolve across the US construction market, Environmental Product Declarations (EPDs) are becoming increasingly common within project specifications and submittal requirements. However, despite growing adoption, there remains a degree of confusion around what EPDs actually represent and, more importantly, how they should (and should not) influence product selection.
This Stormcure Technical Brief, written by James Westaway (CEO), provides a practical overview of EPDs in the context of roofing and waterproofing systems, with a focus on how architects, engineers, and consultants can apply them appropriately in real-world projects.
What is an EPD?
An Environmental Product Declaration (EPD) is a standardized document that reports the environmental impacts of a product based on a Life Cycle Assessment (LCA).
In the US market, EPDs are typically developed in accordance with ISO 21930, which defines how environmental data is calculated, structured, and reported.
At a high level, an EPD provides:
- Quantified environmental impact data (e.g. carbon footprint)
- A consistent format for reporting across products
- Third-party verification for credibility
What do EPDs actually measure?
EPDs break environmental impacts into lifecycle stages, known as modules.
In most US construction applications, the primary focus is on A1–A3 (Cradle-to-Gate) which measures:
- Raw material extraction
- Manufacturing
- Transport and processing prior to delivery
This stage often captures the majority of a product’s embodied carbon and is the most commonly requested data in project documentation.
Why are EPDs becoming more common in the US?
The increasing use of EPDs is largely driven by:
· LEED and green building frameworks
· Public and institutional procurement requirements
· Owner-driven sustainability targets
In many cases, the requirement is straightforward: Provide a compliant, third-party verified EPD as part of the submittal.
This has led to EPDs often being used as a compliance tool, rather than a detailed design analysis input.
EPDs in practice: What they are, and what they are not...
What EPDs are useful for
- Demonstrating compliance with sustainability requirements
- Providing transparent, verified environmental data
- Supporting material disclosure and documentation
What EPDs are not designed to do
- Provide a complete picture of whole-life performance
- Enable precise “like-for-like” product comparisons
- Replace technical evaluation of system performance
This distinction is important. While EPDs provide valuable data, they represent modeled scenarios, not absolute performance outcomes.
Challenges with Comparing EPDs
In theory, EPDs allow comparison between products. In practice, however, this is often difficult, particularly in roofing and waterproofing systems.
Key variables include:
- Coverage rates and application thickness
- Reinforcement types and system build-ups
- Assumed service life
- System boundaries and included components
As seen in broader liquid-applied systems, performance and application context can vary significantly. For example, even within similar categories, systems may range from thin protective layers to fully reinforced membranes with very different durability and functional roles.
As a result, EPD comparisons should be approached with caution and used as one input among many, not a standalone decision-making tool.
When Should EPDs Influence Product Selection?
EPDs should inform decisions in the following scenarios:
1. Compliance-driven projects
Where specifications require:
- LEED credits
- Public procurement criteria
- Documented environmental disclosures
In these cases, the presence of a compliant EPD is often mandatory.
2. Carbon Assessment and Modelling
Some project teams may also use EPDs:
- As inputs to support early-stage material selection
- As data sources for whole-building or whole-life carbon assessments
These are typically more advanced use cases. Teams working at this level will generally be familiar with how to interpret and apply EPD data appropriately.
When Should EPDs NOT Drive Decisions?
EPDs should not override core technical considerations such as:
- Waterproofing performance
- Durability and service life
- Substrate compatibility
- Warranty structure
For example, selecting between fundamentally different system types based solely on A1–A3 carbon data—without considering performance role—can lead to inappropriate specifications.
As with other system comparisons, the functional role of the system must be understood first, before environmental metrics are applied.
A Practical Approach for Specifiers
When reviewing EPDs, consider the following hierarchy:
1. Does the product meet performance requirements?
2. Is it appropriate for the application?
3. Does it have a compliant, verified EPD?
4. How does its environmental data compare within a like-for-like group?
This ensures that sustainability considerations are integrated, rather than isolated.
Summary
- EPDs provide standardized, third-party verified environmental data
- In the US, they are primarily used for compliance and documentation
- The most relevant metric is typically A1–A3 (cradle-to-gate) carbon impact
- Comparisons between products can be complex and limited
- EPDs should inform, and not dictate, specification decisions
EPDs are an important step toward greater transparency in construction materials, but they are only one part of the decision-making process.
Used correctly, they support better-informed specifications. Used in isolation, they risk oversimplifying complex performance requirements.
As with all technical evaluations, context remains critical.
At the same time, the presence of a verified EPD reflects a manufacturer’s investment in transparency, data quality, and alignment with evolving industry expectations. EPDs remove barriers and equip specifiers with the data they need to make informed decisions on environmental impacts within the specification and design process.
