A1 dataset optional from 1 January 2026 when submitting environmental data

From 1 January 2026, it will be possible for producers and suppliers of construction products to submit only the A2 dataset when providing environmental data for an environmental declaration in the Dutch Environmental Database (NMD). Submission of the A1 dataset will then be optional. Official environmental performance calculations will continue to be based on A1 until 1 July 2026. After that date, the final switch to A2 will be made, as announced in the amendments to the Building Decree on the Environment (Bbl) and the Environment and Planning Regulation (Or).

What changes as of 1 January 2026?

• • Data owners may choose to submit only the A2 dataset when including an environmental declaration in the NMD
• The A1 dataset will be optional from that date onwards
• The A2 dataset can already be used for practice purposes, but official environmental performance calculations will continue to be based on A1 until 1 July 2026

Transition to A2 as of 1 July 2026

According to the legislative timetable, the new Bbl and the new Or will enter into force on 1 July 2026. From that moment, official environmental performance calculations will be based on A2 datasets (EN15804+A2).
A2 data have already been available in the calculation tools since 2024, allowing the market to prepare for this transition.

What does this mean for civil engineering (GWW)?

For construction products used in civil engineering projects, separate arrangements apply. Within civil engineering, each client determines per project whether A1 or A2 will be used. It is possible that ongoing projects will continue with A1 until completion.

Submission of both sets remains possible

Even after 1 July 2026, data owners may submit the A1 dataset alongside the mandatory A2 dataset. The following applies:

• A1 datasets must be based on Ecoinvent version 3.6
• A2 datasets are based on Ecoinvent version 3.9.1

What is the difference between A1 and A2?

• Until 2019, environmental performance was calculated using 11 impact categories, the so-called A1 set (according to EN15804+A1)
• With the revised EN15804+A2, this has been expanded to 19 impact categories, including new and more refined indicators
• The switch to A2 therefore means a broader and more detailed assessment of the environmental impact of construction products.

Advice to producers and suppliers

• • As of 1 January 2026, always submit A2 datasets to be prepared for the new legislation
  • Use the period until 1 July 2026 to gain practical experience with A2
  • Take into account specific arrangements in the civil engineering sector

Further information can be found in  the parliamentary letter of 16 June 2025