What is ISO 21930? The International Standard for Construction EPDs

Please note: This article is for educational purposes only. It does not replace the ISO and EN standards. If you work at a university, you probably already have a licence to view the complete standards. If not, please go to your relevant national provider of standards.

ISO 21930 is the international standard that provides core rules for Environmental Product Declarations (EPDs) in construction. While Europe has EN 15804, the rest of the world looks to ISO 21930 for standardised environmental reporting of construction products and services.

This comprehensive guide explains ISO 21930’s requirements, its role in global construction markets, and how it enables environmental transparency across international supply chains.

Understanding ISO 21930: Global Framework for Construction EPDs#

ISO 21930:2017 “Sustainability in buildings and civil engineering works — Core rules for environmental product declarations of construction products and services” establishes the international framework for creating comparable EPDs worldwide.

The standard serves as the foundation for national and regional EPD programmes outside Europe, providing the methodological consistency needed for international trade while allowing regional adaptation.

The Global Context for ISO 21930#

Construction is inherently international. Steel from China, timber from Canada, glass from Japan, and cement from Turkey come together in buildings worldwide. ISO 21930 provides the common language for communicating these products’ environmental impacts across borders.

Unlike regional standards tied to specific regulations, ISO 21930 offers flexibility for different markets while maintaining core comparability. This balance between standardisation and adaptation makes it essential for manufacturers operating globally.

ISO 21930’s Role in International Trade#

For manufacturers exporting internationally, ISO 21930 compliance opens doors:

• North America: LEED accepts ISO 21930 EPDs for materials credits
• Asia-Pacific: Growing markets require ISO-compliant documentation
• Middle East: Major projects specify ISO 21930 for international suppliers
• Latin America: Emerging green building standards reference ISO 21930

The standard’s international recognition reduces trade barriers and verification costs for global supply chains.

The Development and Evolution of ISO 21930#

ISO 21930’s development reflects the construction industry’s need for globally harmonised environmental reporting.

Historical Context#

ISO 21930:2007 – First Edition
The original version emerged as countries recognised the need for international EPD standardisation. It provided basic framework but lacked the detail needed for practical implementation.

ISO 21930:2017 – Current Version
The second edition brought substantial improvements:

• Aligned with EN 15804:2012+A1:2013 structure
• Adopted the modular approach (A-B-C-D modules)
• Enhanced comparability requirements
• Clarified data quality provisions

This 2017 revision created much closer alignment with European practice, though important differences remain.

Relationship with ISO 14040 Series#

ISO 21930 builds upon the ISO 14040 series (Life Cycle Assessment principles) and ISO 14025 (Type III environmental declarations). It doesn’t replace these foundational standards but provides sector-specific interpretation for construction.

The hierarchy works as follows:

• ISO 14040/14044: General LCA methodology
• ISO 14025: General EPD requirements
• ISO 21930: Construction-specific EPD rules
• National standards: Regional adaptations

Core Principles of ISO 21930#

ISO 21930 establishes fundamental principles that guide all construction EPDs created under its framework.

Functional vs Declared Units#

ISO 21930 distinguishes between two approaches for defining the basis of an EPD:

Functional Unit
Used when the EPD covers all life cycle stages (cradle to grave). The functional unit quantifies product performance, such as “thermal resistance of RSI 3.5 per m² for 60 years.”

Declared Unit
Used for partial EPDs (typically cradle to gate). The declared unit is a physical quantity, such as “1 tonne of steel” or “1 m³ of concrete,” without performance requirements.

This flexibility allows manufacturers to create EPDs appropriate to their market needs and data availability.

Modular Information Structure#

Like EN 15804, ISO 21930 organises the building life cycle into information modules:

Production Stage (A1-A3)

• A1: Raw material extraction and processing
• A2: Transport to manufacturer
• A3: Manufacturing

Construction Stage (A4-A5)

• A4: Transport to construction site
• A5: Installation/assembly

Use Stage (B1-B7)

• B1: Use
• B2: Maintenance
• B3: Repair
• B4: Replacement
• B5: Refurbishment
• B6: Operational energy use
• B7: Operational water use

End of Life Stage (C1-C4)

• C1: Deconstruction/demolition
• C2: Transport to disposal
• C3: Waste processing
• C4: Disposal

Benefits and Loads Beyond the System Boundary (Module D)

• Reuse and recycling potentials
• Energy recovery
• Avoided emissions from substitution

System Boundary Requirements#

ISO 21930 requires clear definition of system boundaries using a modular approach. Unlike some regional standards, ISO 21930 allows flexibility in which modules to include:

Mandatory Coverage

• Modules A1-A3 must always be included
• Other modules can be omitted if clearly declared
• Any omissions must be justified and transparent

Cradle to Gate EPDs
Minimum requirement covering A1-A3, common for international trade where use and end-of-life scenarios vary by region.

Cradle to Grave EPDs
Complete coverage of A1-A3, A4-A5, B1-B7, and C1-C4, providing comprehensive life cycle information.

Module D Reporting
Optional but encouraged, allowing communication of recycling benefits and material substitution credits.

Environmental Impact Categories#

ISO 21930 defines core impact categories while allowing regional programmes to add indicators relevant to local priorities.

Mandatory Impact Categories#

All ISO 21930 EPDs must report these environmental impacts:

Global Warming Potential (GWP)
Greenhouse gas emissions in kg CO₂ equivalent, calculated using IPCC characterisation factors. ISO 21930 doesn’t separate biogenic carbon as distinctly as EN 15804+A2.

Ozone Depletion Potential (ODP)
Stratospheric ozone depletion in kg CFC-11 equivalent, based on WMO models.

Acidification Potential (AP)
Potential for acid rain and soil acidification. Regional programmes may use different reference substances (SO₂ or H+ equivalent).

Eutrophication Potential (EP)
Nutrient enrichment impacts. Some programmes separate freshwater, marine, and terrestrial eutrophication.

Photochemical Oxidant Creation Potential (POCP)
Smog formation potential, typically in ethene or NMVOC equivalents.

Abiotic Depletion Potential

• Elements (ADPE): Depletion of non-renewable elements
• Fossil fuels (ADPF): Depletion of fossil energy resources

Regional Variations in Impact Assessment#

ISO 21930’s flexibility allows regional adaptation of characterisation methods:

North America
Often uses TRACI (Tool for Reduction and Assessment of Chemical and Environmental Impacts) methods developed by the US EPA.

Japan
May apply LIME (Life-cycle Impact assessment Method based on Endpoint modeling) for local relevance.

Australia/New Zealand
Can incorporate regional characterisation factors for water scarcity and land use.

This flexibility ensures EPDs remain relevant to local environmental priorities while maintaining international comparability for core indicators.

Data Requirements and Quality#

ISO 21930 establishes data requirements that balance accuracy with practical feasibility for international supply chains.

Specific vs Generic Data#

Specific Data Requirements
Manufacturers must use specific data for:

• Processes under their operational control
• Main raw material inputs where available
• Energy consumption in manufacturing

Generic Data Allowances
Generic data can be used for:

• Upstream processes beyond manufacturer control
• Minor materials below cut-off thresholds
• End-of-life scenarios
• Regional electricity grids

The standard recognises that international supply chains make complete specific data collection impractical.

Cut-off Rules#

ISO 21930 permits excluding minor flows:

• Maximum 5% of total mass and energy
• No more than 5% of any environmental impact
• Hazardous substances cannot be excluded

These thresholds provide practical relief while maintaining EPD integrity.

Data Quality Assessment#

The standard requires documenting:

• Temporal coverage: Age of data and period covered
• Geographical coverage: Regional representativeness
• Technological coverage: Production methods included
• Precision: Variability and uncertainty
• Completeness: Data gaps and estimations
• Representativeness: How well data reflects actual production

This transparency enables users to assess EPD reliability for their specific applications.

Allocation Procedures#

ISO 21930 provides detailed guidance on handling multi-output processes, a critical issue for many construction materials.

Allocation Hierarchy#

When processes produce multiple products, impacts must be allocated following this hierarchy:

1. Avoid allocation through system expansion where possible
2. Physical relationships (mass, energy content) when unavoidable
3. Economic value as last resort

Co-products vs Waste#

ISO 21930 makes important distinctions:

• Co-products: Materials with economic value receive allocated impacts
• Waste: Materials requiring disposal carry no impacts from production (impacts already allocated to products)

This approach differs from some regional interpretations, affecting results for products using recycled content.

Recycling and Recovery#

The standard provides specific rules for recycled materials:

• Recycled inputs enter burden-free (impacts allocated to original product)
• Recycling processes themselves carry impacts
• Credits for avoided primary production can be claimed in Module D

These rules significantly impact EPD results for metals, aggregates, and other commonly recycled construction materials.

Scenario Development and Use Stage Modeling#

ISO 21930 requires transparent scenarios for life cycle stages beyond manufacturing.

Reference Service Life (RSL)#

EPDs must declare a Reference Service Life considering:

• Inherent product properties
• Design application parameters
• Indoor/outdoor environment conditions
• Usage conditions
• Maintenance level

ISO 15686-1, -2, -7, and -8 provide methodologies for RSL estimation. The RSL forms the basis for use stage scenarios and replacement calculations.

Use Stage Scenarios#

For modules B1-B7, scenarios must be:

• Realistic: Based on actual practice, not theoretical best-cases
• Justified: Supported by evidence or standards
• Transparent: Clearly documented assumptions
• Representative: Reflecting typical applications

The standard allows multiple scenarios for different applications, recognising that products perform differently in various contexts.

End-of-Life Scenarios#

Module C scenarios should reflect current waste management practice:

• Regional recycling rates
• Typical disposal methods
• Existing infrastructure
• Current regulations

Future improvements in recycling or energy recovery shouldn’t be assumed unless infrastructure exists.

Comparison Rules and Functional Equivalence#

ISO 21930 establishes strict conditions for comparing EPDs, preventing misleading comparisons.

Requirements for Valid Comparison#

EPDs can only be compared when:

• Functional or declared units are equivalent
• System boundaries are identical
• Data quality is comparable
• Scenarios represent the same context
• Regional variations are considered

Building Level Consideration#

Like EN 15804, ISO 21930 emphasises that meaningful comparison requires building context:

• Installation requirements
• Maintenance needs
• Service life differences
• Performance characteristics
• End-of-life options

Simple comparison of manufacturing impacts (A1-A3) without considering full life cycle performance can be misleading.

Functional Equivalence#

Products must deliver equivalent function to be comparable. A tonne of structural steel isn’t comparable to a tonne of reinforcement bar, despite both being steel products. The specific application determines functional equivalence.

Programme Operations and Mutual Recognition#

ISO 21930 EPDs operate through programme operators who ensure consistency and credibility.

Programme Operator Roles#

EPD programmes administer ISO 21930 implementation:

• Develop programme-specific PCRs based on ISO 21930
• Manage verification processes
• Maintain EPD registries
• Ensure ongoing compliance
• Handle updates and revisions

Major ISO 21930 Programmes#

Leading programmes operating under ISO 21930 include:

North America

• UL Environment (USA)
• ASTM International EPD Program (USA)
• CSA Group (Canada)

Asia-Pacific

• JEA-EcoLeaf (Japan)
• Korea Environmental Industry & Technology Institute (South Korea)
• EPD Australasia (Australia/New Zealand)

Other Regions

• EPD Brazil
• Global EPD (Spain, with international reach)
• EPD Middle East

Mutual Recognition Challenges#

Unlike Europe’s ECO Platform for EN 15804, ISO 21930 lacks a unified mutual recognition framework. Each programme maintains its own:

• Verification requirements
• PCR interpretations
• Impact assessment methods
• Database preferences

This fragmentation increases costs for manufacturers seeking multiple markets. Efforts toward mutual recognition continue through the Global EPD Network, though progress remains limited.

ISO 21930 in Green Building Certification#

Major green building standards worldwide recognise ISO 21930 EPDs, driving market demand.

LEED v4/v4.1#

Leadership in Energy and Environmental Design awards points for products with ISO 21930 EPDs:

• Building Product Disclosure and Optimization credits
• Whole-building life cycle assessment credits
• Supply chain transparency documentation

LEED’s international reach makes ISO 21930 compliance valuable globally.

BREEAM International#

While BREEAM UK focuses on EN 15804, BREEAM International accepts ISO 21930 EPDs for:

• Mat 01 Environmental impacts from construction products
• Mat 02 Environmental Product Declarations
• Mat 06 Material efficiency

Regional Schemes#

National green building programmes increasingly reference ISO 21930:

• Green Star (Australia): Materials life cycle impacts credits
• CASBEE (Japan): Environmental load reduction assessment
• EDGE (Emerging markets): Materials embodied energy documentation
• WELL Building Standard: Materials transparency requirements

Living Building Challenge#

The Materials Petal requires transparency documentation, accepting ISO 21930 EPDs as compliance pathways for:

• Red List ingredient disclosure
• Embodied carbon reporting
• Responsible sourcing verification

Regional Adaptations and Standards#

While ISO 21930 provides the framework, regional adaptations address local needs.

North American Adaptations#

ASTM Standards The USA often uses ISO 21930 through ASTM adaptations:

• ASTM E2921: Minimum criteria for comparing whole building LCAs
• Product-specific PCRs referencing ISO 21930

UL PCRs UL Environment develops detailed PCRs under ISO 21930 framework for specific products:

• Concrete (UL 10010)
• Gypsum panels (UL 10010-5)
• Steel products (UL 10010-4)

These PCRs add specificity while maintaining ISO 21930 compliance.

Asia-Pacific Variations#

Japanese Approach Japan’s EcoLeaf programme implements ISO 21930 with:

• Japanese language requirements
• Local impact assessment methods
• Domestic database preferences
• Cultural context for use scenarios

Australian/New Zealand Practice EPD Australasia adapts ISO 21930 considering:

• Water scarcity impacts (crucial for Australia)
• Seismic performance requirements (New Zealand)
• Indigenous land use considerations
• Regional transport distances

Emerging Markets#

Countries developing EPD systems often start with ISO 21930:

• India: Emerging Green Product Certification references ISO 21930
• Brazil: Adapting ISO 21930 for tropical conditions
• South Africa: Developing construction EPD requirements
• UAE: Estidama credits for ISO 21930 EPDs

Differences from EN 15804#

Understanding how ISO 21930 differs from EN 15804 helps manufacturers navigate both standards.

Structural Differences#

Module D Requirements

• ISO 21930: Optional reporting
• EN 15804+A2: Mandatory reporting

Biogenic Carbon

• ISO 21930: Included in total GWP
• EN 15804+A2: Separated into distinct categories

Impact Categories

• ISO 21930: Core set with regional flexibility
• EN 15804+A2: Expanded mandatory indicators

Methodological Variations#

Allocation Approaches

• ISO 21930: More flexible on recycled content
• EN 15804: Stricter cut-off approach

Characterisation Methods

• ISO 21930: Allows regional methods (TRACI, LIME)
• EN 15804: Mandates EC-JRC factors

Data Requirements

• ISO 21930: Greater flexibility for international chains
• EN 15804: Stricter specific data requirements

Market Implications#

These differences mean:

• EPDs cannot be directly converted between standards
• Dual verification may be needed for global markets
• Results differ even for identical products
• Comparison across standards is invalid

Creating ISO 21930 Compliant EPDs#

Developing ISO 21930 EPDs requires systematic approach adapted to international contexts.

Step 1: Programme Selection#

Choose an appropriate programme operator considering:

• Target markets
• Verification costs
• PCR availability
• Database access
• Language requirements
• Mutual recognition agreements

Step 2: PCR Development or Selection#

Identify applicable Product Category Rules:

• Check existing PCRs in your programme
• Participate in PCR development if needed
• Ensure alignment with ISO 21930 requirements
• Consider regional market expectations

Step 3: Life Cycle Assessment#

Conduct LCA following ISO 21930 requirements:

• Define functional/declared unit
• Establish system boundaries
• Collect specific data where required
• Select appropriate generic data
• Apply regional characterisation methods
• Document all assumptions

Step 4: Scenario Development#

Create realistic scenarios for:

• Transport to site (Module A4)
• Installation (Module A5)
• Use stage activities (B1-B7)
• End-of-life treatment (C1-C4)
• Benefits beyond the boundary (Module D if included)

Step 5: Documentation#

Prepare comprehensive documentation:

• EPD report following programme format
• Background LCA report
• Data quality assessment
• Scenario justifications
• Verification package

Step 6: Verification#

Complete third-party verification:

• Select qualified verifier
• Provide complete documentation
• Address verification findings
• Obtain verification statement

Step 7: Registration and Publication#

Finalise the EPD process:

• Register with programme operator
• Obtain EPD reference number
• Publish in programme database
• Communicate to stakeholders

Common Challenges and Solutions#

Challenge: Multiple Market Requirements#

Problem: Different regions require different EPD approaches
Solution: Develop core LCA model adaptable to multiple standards

Challenge: Data Availability#

Problem: Limited specific data for international supply chains
Solution: Use conservative generic data with clear documentation

Challenge: Scenario Development#

Problem: Uncertain use conditions in diverse markets
Solution: Provide multiple scenarios for different applications

Challenge: Verification Costs#

Problem: Multiple verifications for different programmes
Solution: Seek programmes with mutual recognition agreements

Challenge: Language Barriers#

Problem: EPDs needed in multiple languages
Solution: Develop modular content easily translated

Future Directions for ISO 21930#

ISO 21930 continues evolving to meet global sustainability needs.

Potential Revision Topics#

Alignment with EN 15804+A2 Future revisions may incorporate:

• Biogenic carbon separation
• Expanded environmental indicators
• Mandatory Module D reporting
• Enhanced data quality requirements

Circular Economy Integration Emerging focus areas include:

• Material circularity indicators
• Design for disassembly metrics
• Durability assessments
• Recycled content verification

Digital Transformation Evolution toward digital EPDs:

• Machine-readable formats
• API integration capabilities
• Blockchain verification
• BIM integration

Harmonisation Efforts#

The Global EPD Network works toward:

• Common verification protocols
• Harmonised PCR development
• Shared database structures
• Mutual recognition frameworks

Success would significantly reduce costs and complexity for international manufacturers.

Regulatory Drivers#

Emerging regulations may accelerate ISO 21930 adoption:

• Carbon border adjustments requiring EPDs
• Green public procurement mandates
• Supply chain transparency laws
• Climate disclosure requirements

ISO 21930 vs Regional Standards#

Understanding when to use ISO 21930 versus regional standards helps optimise EPD strategies.

When to Use ISO 21930#

Choose ISO 21930 for:

• International export markets
• Multiple country requirements
• Global supply chain documentation
• International project specifications
• Markets without regional standards

When Regional Standards Prevail#

Regional standards may be better for:

• Single market focus (EN 15804 for Europe)
• Regulatory compliance requirements
• Local green building certification
• Domestic public procurement
• Market-specific optimization

Dual Standard Strategies#

Many manufacturers maintain both:

• ISO 21930 for international baseline
• Regional standards for specific markets
• Modular LCA models serving both
• Coordinated update cycles
• Unified documentation systems

Conclusion: ISO 21930 as the Global EPD Framework#

ISO 21930 provides the essential international framework for construction EPD development. While it may lack the prescriptive detail of regional standards like EN 15804, its flexibility enables global application across diverse markets and regulatory contexts.

For manufacturers operating internationally, ISO 21930 offers a pathway to environmental transparency that transcends borders. Its recognition by major green building schemes worldwide makes it valuable for market access, while its modular structure provides scalability from simple declarations to comprehensive life cycle reporting.

The standard’s balance between standardisation and flexibility reflects the reality of global construction markets. While this creates some challenges for direct comparison, it enables practical implementation across vastly different contexts; from Japanese high-rises to Brazilian infrastructure to Middle Eastern megaprojects.

As environmental regulations proliferate globally and supply chain transparency becomes mandatory, ISO 21930 expertise becomes increasingly strategic. Whether you’re a manufacturer seeking international markets, a specifier evaluating global suppliers, or a programme operator developing EPD systems, understanding ISO 21930 is essential for navigating the international landscape of construction sustainability.

The future likely holds greater harmonisation between ISO 21930 and regional standards, driven by trade needs and climate imperatives. Until then, ISO 21930 remains the crucial bridge enabling environmental transparency in our interconnected global construction industry.