What is EN 15804? The Complete Guide to EN Construction EPD Standards

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.

EN 15804 is the European standard that defines how to create Environmental Product Declarations (EPDs) for construction products. Whether you’re specifying sustainable materials, developing EPDs, or conducting Life Cycle Assessments, understanding EN 15804 is essential for navigating European construction markets.

This comprehensive guide explains EN 15804’s requirements, its evolution through the +A2 amendment, and how it shapes environmental reporting across the construction industry.

Understanding EN 15804: Core Product Category Rules for Construction#

EN 15804 provides the core Product Category Rules (PCR) for all construction products and services in Europe. Think of it as the master template ensuring every EPD – whether for concrete, steel, insulation, or timber – follows identical methodologies, making environmental impacts genuinely comparable.

The standard’s full title reveals its scope: “EN 15804:2012+A2:2019+AC:2021 – Sustainability of construction works – Environmental product declarations – Core rules for the product category of construction products.”

Why EN 15804 Matters#

The construction sector accounts for approximately 40% of Europe’s carbon emissions. EN 15804 creates the framework for measuring, reporting, and comparing these environmental impacts consistently. Without this standardisation, comparing the environmental performance of different products would be meaningless.

The standard ensures that when an architect compares EPDs for two insulation products, they’re using data calculated with identical methods, system boundaries, and impact categories. This comparability is fundamental to making informed sustainable design decisions.

The Evolution of EN 15804: From 2012 to Today#

EN 15804 has undergone significant evolution since its initial publication, with each version bringing important changes:

EN 15804:2012 – The Foundation#

The original version established the modular structure and basic requirements for construction EPDs. It introduced the A-B-C-D module system that became the global standard for organising building life cycle information.

EN 15804:2012+A1:2013 – Harmonised Methods#

The first amendment added harmonised environmental impact assessment methods, ensuring all EPDs used consistent characterisation factors and models. This improved comparability significantly.

EN 15804:2012+A2:2019 – The Revolution#

The second amendment brought fundamental changes:

• Mandatory reporting of all life cycle modules (A-D)
• Separated biogenic carbon accounting
• Additional environmental indicators
• Alignment with EU Product Environmental Footprint methods

EN 15804:2012+A2:2019+AC:2021 – Current Version#

The August 2021 corrigendum provided technical corrections, particularly for eutrophication units, without changing fundamental requirements. This version became mandatory in October 2022, replacing all previous versions.

Life Cycle Modules: The Building Blocks of EN 15804#

EN 15804 organises the building life cycle into information modules, creating a standardised framework for reporting environmental impacts across distinct life stages.

Product Stage (A1-A3)#

The product stage covers everything from raw material extraction to the factory gate:

A1 – Raw Material Extraction and Processing
All processes from extraction through initial processing. For steel, this includes iron ore mining, beneficiation, and transport to processing facilities.

A2 – Transport to Manufacturer
Movement of raw materials to the manufacturing facility. The standard requires specific transport scenarios based on actual supply chains.

A3 – Manufacturing
All production processes including energy consumption, waste generation, and emissions. This module ends when the product leaves the factory gate.

Construction Stage (A4-A5)#

A4 – Transport to Construction Site
Delivery from factory to site, including any intermediate storage or distribution centres.

A5 – Installation/Construction
Site activities including material wastage, auxiliary materials, energy use, and waste treatment during installation.

Use Stage (B1-B7)#

The use stage spans the building’s operational life:

B1 – Use
Direct emissions from the product during use (e.g., VOC emissions from paints).

B2 – Maintenance
Scheduled maintenance activities and their environmental impacts.

B3 – Repair
Corrective maintenance to restore functionality.

B4 – Replacement
Complete replacement of the product during the building’s life.

B5 – Refurbishment
Major renovation activities involving the product.

B6 – Operational Energy Use
Energy consumed by technical building systems (not applicable to all products).

B7 – Operational Water Use
Water consumed by technical building systems (not applicable to all products).

End of Life Stage (C1-C4)#

C1 – Deconstruction/Demolition
On-site activities to remove the product from the building.

C2 – Transport to Disposal
Movement to waste processing or disposal facilities.

C3 – Waste Processing
Treatment for reuse, recovery, or recycling.

C4 – Final Disposal
Landfilling or other final disposal methods.

Module D – Beyond the System Boundary#

Module D reports benefits and loads beyond the product system boundary. This includes:

• Recycling potential of materials
• Energy recovery from incineration
• Avoided burdens from material substitution
• Carbon sequestration potential

Module D uses current average technology for substitution calculations, not future projections. This prevents speculation about future recycling rates or energy grids.

Environmental Impact Categories in EN 15804+A2#

EN 15804+A2 significantly expanded the environmental indicators required in EPDs, moving beyond traditional LCA impacts to address emerging environmental concerns.

Core Environmental Indicators#

Climate Change Categories
The standard now separates Global Warming Potential into distinct categories:

• Climate Change – Fossil (GWP-fossil): CO₂ emissions from fossil fuels
• Climate Change – Biogenic (GWP-biogenic): CO₂ from biological sources
• Climate Change – Land Use (GWP-luluc): Impacts from land use change
• Climate Change – Total (GWP-total): Sum of all three categories

This separation provides transparency about carbon sources, particularly important for bio-based materials.

Ozone Depletion Potential (ODP)
Measured in kg CFC-11 equivalent, tracking substances that deplete stratospheric ozone.

Acidification Potential (AP)
Expressed as mol H+ equivalent, measuring the potential for acid rain and soil acidification.

Eutrophication Potentials
Three separate categories address nutrient pollution:

• Eutrophication – Aquatic Freshwater (EP-freshwater): P equivalent
• Eutrophication – Aquatic Marine (EP-marine): N equivalent
• Eutrophication – Terrestrial (EP-terrestrial): mol N equivalent

Photochemical Ozone Creation Potential (POCP)
Measures smog formation potential in kg NMVOC equivalent.

Abiotic Depletion Potentials

• Elements (ADP-elements): Depletion of non-renewable elements in kg Sb equivalent
• Fossil fuels (ADP-fossil): Depletion of fossil energy resources in MJ

Water Scarcity Footprint (WDP)
Added in +A2, measuring water consumption impacts in m³ world equivalent.

Additional Environmental Indicators#

EN 15804+A2 introduced new indicators that may be declared:

Particulate Matter Emissions (PM)
Disease incidence from fine particle emissions.

Ionising Radiation (IRP)
Human exposure efficiency relative to U235.

Ecotoxicity – Freshwater (ETP-fw)
Comparative Toxic Units for ecosystems (CTUe).

Human Toxicity

• Cancer effects (HTP-c): CTUh for carcinogenic impacts
• Non-cancer effects (HTP-nc): CTUh for other toxic effects

Land Use Related Impacts (SQP)
Soil quality index based on LANCA methodology.

Characterisation Factors and Methods#

EN 15804+A2 mandates specific characterisation factors from the European Commission Joint Research Centre (EC-JRC). These factors, identified as “EN_15804” in the ILCD database, ensure methodological consistency across all EPDs.

The standard requires using Environmental Footprint 3.0 methods, representing the latest scientific consensus on impact assessment. This alignment with EU policy ensures EPDs remain relevant for regulatory compliance.

Biogenic Carbon: The EN 15804+A2 Revolution#

The treatment of biogenic carbon represents the most significant change in EN 15804+A2. The standard now requires complete transparency about carbon from biological sources throughout the product life cycle.

Tracking Biogenic Carbon Flows#

EPDs must report biogenic carbon as both removals and emissions:

• Removals: CO₂ absorbed during biomass growth (reported as negative emissions)
• Emissions: CO₂ released during combustion, decomposition, or processing

For timber products, this means reporting the carbon stored in wood (removal) separately from emissions during end-of-life treatment.

Critical Biogenic Carbon Rules#

No Carbon Offsets
“Carbon offset shall not be included in the calculation of the GWP.” The standard explicitly prohibits using offsets to reduce reported impacts.

No Temporal Discounting
“The effect of temporary carbon storage and delayed emissions shall not be included.” Products cannot claim benefits from temporarily storing carbon.

Material Inherent Properties
EPDs must declare:

• Biogenic carbon content at the factory gate
• Carbonation potential for cementitious materials
• Net calorific value for combustible materials

These properties enable proper end-of-life scenario modelling in building LCAs.

Implications for Bio-based Products#

The biogenic carbon rules fundamentally change how bio-based products present environmental credentials. A timber product EPD shows:

• Large negative emissions in Module A (carbon sequestration)
• Corresponding positive emissions in Module C (end-of-life release)
• Net zero biogenic impact over the full life cycle (assuming sustainable forestry)

This transparency prevents greenwashing while properly crediting sustainable biomass use.

Data Quality and Requirements#

EN 15804 establishes strict data quality requirements to ensure EPD reliability and comparability.

Specific vs Generic Data#

Specific Data Requirements
Manufacturers must use specific (primary) data for processes under their control:

• Manufacturing energy consumption (Module A3)
• Production waste and emissions
• Transport distances for known supply chains

Generic Data Application
Generic (secondary) data can be used for:

• Upstream processes (raw material production)
• Downstream processes (end-of-life scenarios)
• Grid electricity datasets
• Background processes

The standard requires documenting data sources, age, technological representativeness, and geographical coverage for all generic datasets.

Cut-off Criteria#

EN 15804 permits excluding minor flows under strict conditions:

• Maximum 1% of total mass
• Maximum 1% of total primary energy
• Maximum 5% of any environmental impact category
• Total excluded flows cannot exceed 5% of impacts

Hazardous materials and substances on the REACH SVHC list cannot be excluded regardless of quantity.

Scenario Development#

For modules beyond A1-A3, EPDs must provide scenarios based on:

• Current technology (not future projections)
• Realistic and probable alternatives
• Demonstrated practical feasibility
• Reference Service Life (RSL) aligned with building design life

Scenarios must be transparent, justified, and representative of actual practice. Speculative scenarios about future recycling infrastructure or energy grids are prohibited.

Comparability: The Building Context Rule#

EN 15804 contains strict rules about comparing EPDs, centered on one principle: comparison must occur within a building context.

The Fundamental Rule#

“Comparison of construction products using EPD information shall be based on the product’s use in and its impacts on the building.”

This means isolated product comparisons are invalid. You cannot simply compare two insulation materials’ carbon footprints without considering:

• Installation requirements
• Service life differences
• Maintenance needs
• End-of-life scenarios
• Influence on building operational performance

Requirements for Valid Comparison#

EPDs can only be compared when:

• All life cycle modules (A-D) are included
• Functional requirements are identical
• Building context is defined
• Excluded processes are the same
• System boundaries align perfectly

The standard explicitly states: “EPD that are not in a building context are not tools to compare construction products.”

Implications for Specification#

This rule fundamentally affects how specifiers use EPDs. Rather than choosing products with the lowest Module A impacts, they must consider total life cycle performance within specific building applications. An insulation material with higher manufacturing impacts might deliver lower total impacts through better thermal performance over the building’s life.

Verification and Programme Operations#

EN 15804 EPDs require third-party verification to ensure credibility and compliance.

Verification Requirements#

Independent Third-Party Verification
All EPDs must be verified by an accredited third party independent of the LCA practitioner and manufacturer. Verifiers check:

• LCA methodology compliance
• Data quality and documentation
• Scenario plausibility
• Calculation accuracy
• Reporting completeness

Programme Operator Role
EPD programmes administer the verification process, maintain registries, and ensure consistency. Major European programmes include:

• The International EPD System (Sweden)
• IBU (Germany)
• INIES (France)
• BRE (UK)
• EPD Norge (Norway)

Mutual Recognition#

The ECO Platform enables mutual recognition between European EPD programmes. An EPD verified under one ECO Platform member programme is recognised by all others, reducing verification costs and market barriers.

Integration with Building Standards#

EN 15804 doesn’t exist in isolation – it’s designed to feed building-level environmental assessments.

EN 15978: Building LCA Standard#

EN 15978 uses EN 15804 EPDs as data sources for whole-building Life Cycle Assessment. The modular structure ensures EPD data aggregates properly at building level:

• Consistent system boundaries
• Aligned impact categories
• Compatible scenarios
• Additive information modules

Building Assessment Schemes#

Major certification systems increasingly require or reward EN 15804 EPDs:

• BREEAM: Credits for EPD use and life cycle costing
• DGNB: Mandatory building LCA using EPD data
• LEED v4: Materials credits for products with EPDs
• HQE: Full building LCA requirements

Regulatory Integration#

The revised Construction Products Regulation (CPR) increasingly references EN 15804:

• 2026: Mandatory GWP declaration for many products
• 2030: Full EPD requirements for regulated products
• Digital Product Passports will incorporate EPD data

The Future of EN 15804#

EN 15804 continues evolving to meet policy and market needs.

Anticipated Developments#

Digital Transformation
Machine-readable EPDs using ILCD+EPD format will enable:

• Automated building LCA calculations
• Real-time environmental optimization
• Integration with BIM workflows
• Digital Product Passport compliance

Scope Expansion
Future revisions may address:

• Circular economy indicators
• Social impact categories
• Biodiversity metrics
• Chemical hazard assessment

Methodological Refinement
Ongoing scientific developments will refine:

• Biogenic carbon accounting for short-rotation crops
• Dynamic LCA methods
• Consequential modelling approaches
• Regionalized impact assessment

Practical Implementation Guide#

Creating EN 15804-compliant EPDs requires systematic approach and attention to detail.

Step 1: Define the Product#

• Identify the declared/functional unit
• Establish system boundaries
• Document product composition
• Determine applicable modules

Step 2: Collect Data#

• Gather specific manufacturing data
• Identify supply chain information
• Select appropriate generic datasets
• Document all assumptions

Step 3: Model the Life Cycle#

• Use EN 15804-compliant LCA software
• Apply correct characterisation factors
• Develop realistic scenarios
• Calculate all required indicators

Step 4: Create the EPD#

• Follow EN 15942 format requirements
• Include all mandatory information
• Provide transparent documentation
• Ensure traceability to LCA model

Step 5: Verification#

• Select accredited verifier
• Provide complete documentation
• Address verification findings
• Register with programme operator

Step 6: Maintenance#

• Monitor for significant changes
• Update before five-year expiry
• Track standard revisions
• Maintain supporting documentation

Common Pitfalls and How to Avoid Them#

Biogenic Carbon Errors#

Pitfall: Claiming carbon neutrality based on biogenic content
Solution: Report removals and emissions separately, showing full cycle

Module D Speculation#

Pitfall: Using future recycling rates or energy grids
Solution: Base calculations on current average technology

Incomplete Scenarios#

Pitfall: Providing vague end-of-life scenarios
Solution: Develop specific, justified scenarios based on current practice

Data Quality Issues#

Pitfall: Using outdated or geographically inappropriate data
Solution: Document data quality and use region-specific datasets where possible

Comparison Misuse#

Pitfall: Marketing products as “better” based on single indicators
Solution: Present complete life cycle results in building context

Conclusion: EN 15804 as the Foundation for Sustainable Construction#

EN 15804 provides the essential framework for measuring and communicating construction products’ environmental impacts. Its comprehensive approach – from raw materials through end-of-life – ensures decision-makers have reliable, comparable information for sustainable design choices.

The standard’s evolution, particularly through the +A2 amendment, reflects growing understanding of environmental complexity. Separating biogenic carbon, adding new impact categories, and mandating end-of-life reporting creates transparency while preventing greenwashing.

For manufacturers, EN 15804 EPDs are becoming essential for market access. For specifiers, they provide the standardised data needed for sustainable design. For the construction industry, they represent a critical tool in the transition to net-zero building.

Understanding EN 15804 isn’t just about compliance – it’s about participating effectively in the sustainable construction transformation. As environmental regulations tighten and market demand for transparency grows, EN 15804 expertise becomes increasingly valuable for all construction stakeholders.

Whether you’re developing EPDs, specifying materials, or assessing building sustainability, EN 15804 provides the common language for environmental performance in construction. Master its requirements, and you’ll be equipped to navigate the evolving landscape of sustainable building.