Calculation tools

Since 2 September 2024, the A2 set has been available alongside the A1 set in calculation tools, so that the market could prepare for the transition. As of 7 January 2026, submitting A1 data for environmental declarations 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 the A2 set. This phased introduction has given the sector the opportunity to gain experience with the use of the  A2 set.

Please note that this information is updated regularly! Last update: 26-6-2026

The table below shows all calculation tool owners currently validated for the Assessment Method for Environmental Performance of Buildings version 2.0 (excluding the optional Chapter 4). The table distinguishes between calculation tools for the buildings sector (B&U) and civil engineering (GWW), and between validation for the A1 and A2 sets. This makes it clear for each tool owner which application areas and datasets the validation applies to. This table will be expanded when new or additional calculation methods are introduced.

If an end date is stated for a calculation tool, the validation applies up to and including that date. Calculations carried out with that tool after this date are not validated by Stichting NMD, regardless of the reference date used. Calculations carried out before the end date remain valid.

Validated calculation tools

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What are validated calculation tools?

A validated calculation tool is private calculation software that has been validated by Stichting NMD for the correct and uniform implementation of the Assessment Method(s) and the associated environmental data from the Dutch Environmental Database.

Validation status

The validated status indicates that the tool has successfully completed the validation procedure and therefore delivers reliable and reproducible environmental performance calculations, ensuring that users obtain the same results for identical input. Validation is carried out in accordance with the Validation Protocol, which sets out the standardised approach for validating calculations and results and safeguards quality and consistency within the environmental performance system. To retain the validated status, tool owners are validated twice a year.

In addition to the validated calculations, a calculation tool may include additional functionalities or calculations. This page specifies for each tool exactly which components and calculations the validation applies to.

What does validation mean?

A calculation tool is validated when it has been established that the Assessment Method for Environmental Performance of Buildings has been correctly implemented in the software. Validation covers the mathematical application of the method and the use of the correct environmental data from the Dutch Environmental Database.

Planning

At present, several calculation tool owners are working on the implementation and validation of the optional Chapter 4 calculations (MEPG calculation method). The deadline and release of the MEPG calculation method are scheduled for 1 April 2026. The WLC-GWP calculation method is still under development; once the validation planning is known, this page will be updated.

Since 2 September 2024, the A2 set has been available in most calculation tools alongside the existing A1 set, allowing the market to prepare in a timely manner. As of 1 July 2026, the A2 set (EN 15804+A2) and the new environmental performance requirements are in effect.

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