Calculating with A1 set and A2 set
As of 1 July 2026, EPB calculations for new buildings in the buildings sector are based on set A2 (EN 15804+A2). This page explains what this transition means for environmental data, environmental declarations and calculations in practice.
For LCA practitioners, calculation tool providers, data owners and users of environmental data in the construction sector
As of 1 July 2026, the transition to set A2 is in effect for EPB calculations in the buildings sector. Set A2 contains 19 environmental impact categories, compared to 11 in set A1, and is applied together with a new, designated weighting set. The environmental data in the Dutch Environmental Database has been prepared for this transition. LCAs for new environmental declarations are compiled on the basis of set A2; set A1 remains available for calculations where this still applies.
Work instruction for LCA compilation based on set A2
To support LCA practitioners in correctly applying set A2, Stichting NMD commissioned SGS Search to develop a work instruction. This helps with the consistent compilation and verification of LCAs based on the 19 impact categories of set A2, with practical guidance on topics including the ecoinvent 3.9.1 database and differences with set A1. The instruction is also relevant for contracting authorities seeking to formulate a consistent tender requirement.
Transition from A1 to A2
Since 1 January 2021, it has been mandatory to submit two sets of environmental data for an environmental declaration in the Dutch Environmental Database: a set based on set A1 (EN 15804+A1) and a set based on set A2 (EN 15804+A2).
This is how Stichting NMD prepared the database for the transition to using set A2 for calculating environmental impact.
Set A1 consists of 11 environmental impact categories. With the revision of the standard (EN 15804+A2), a new set has been designated: set A2. This consists of 19 impact categories. The new set of environmental impact categories is based on a method embraced by the European Commission.
The main change in this transition is the adjustment of the environmental impact categories for acidification, eutrophication, photochemical ozone creation, human toxicity and ecotoxicity. Compared to the previous set, the new set has been divided into sub-indicators and additional indicators have been added.
The new classification and expansion of categories, together with the newly designated weighting set, has implications for the environmental profile of the construction products and materials considered. Amending the environmental profile also changes the environmental performance of the construction material or product, as environmental performance is a numerical representation of the environmental profile. The new set A2 has been taken into account in preparation for the tightening of the environmental performance requirement.
As of 1 July 2026, calculating with set A2 and the new weighting set is officially in effect for EPB calculations in the buildings sector. Read more about what this change means for environmental performance calculations for new buildings
Preparation period
To enable the market to prepare for all the changes, it has been possible since 1 September 2024 to calculate with set A2 and the new weighting set in buildings sector calculation tools, alongside set A1 with the current weighting set. For calculations with set A2, the new weighting set from the publication of the amended Environmental Regulation is applied.
Category 3 environmental declarations with set A2
The Dutch Environmental Database is also being enriched with new category 3 buildings sector environmental declarations containing only set A2. In these environmental declarations, which are based on the existing category 3 buildings sector data, a quality improvement has also been made. However, this quality improvement also causes the data in these environmental declarations to differ from the current category 3 buildings sector environmental declarations that served as the starting point.
This data contains the label 'A2' in the title, so the user can immediately see that these declarations contain only the A2 set and therefore cannot be used for calculations with the A1 set. No changes will be made to the current category 3 buildings sector data (which contains only A1 data) and this will remain available for EPB calculations.
Sufficient qualitative data
Stichting NMD has been preparing for the transition to set A2 for some time, including through projects such as the Acceleration campaign. Owners of category 1 and 2 environmental declarations are alerted and encouraged to enrich their environmental declaration with A2 data in a timely manner.
Extra attention is also being paid to data quality. With the expansion of the environmental impact categories and the new weighting set, the ECIs of environmental declarations are shifting. The impact of this shift has already been carefully considered through impact analyses. Where necessary, Stichting NMD will take action, in close collaboration with the owners of the relevant data, to ensure quality.
Related topics
- As of 1 July 2026: revised Assessment Method and new EPB requirements in effect
- The 19 environmental impact categories explained
- Weighting set and shadow costs
- Assessment Method for Environmental Performance of Buildings
- Overview of changes to the Assessment Method and EPB requirements
- View environmental declarations in the Dutch Environmental Database (Viewer)
- Information for LCA practitioners and verifiers
Frequently asked questions calculating with the A2 set
As of 7 January 2026, submitting A1 data for environmental declarations in the Dutch Environmental Database became optional; A2 data is mandatory from that date. As of 1 July 2026, EPB calculations in the buildings sector are required to be based on set A2 (EN 15804+A2), in accordance with the amended Environmental Buildings Decree (Bbl) and the Environmental Regulation.
From 2 September 2024, it was possible to calculate with set A2 and the new weighting set in validated calculation tools, alongside set A1. As of 7 January 2026, submitting A1 data for environmental declarations became optional. From 1 July 2026, EPB calculations are required to be based on set A2.
The transition to the A2 set aims to provide a more complete and accurate assessment of the environmental impact of construction projects, in line with the latest scientific insights and European standards.
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