Frequently asked questions about the Viewer

On this page you will find information about the purpose and use of the NMD-Viewer. The NMD-Viewer is managed by the National Environmental Database Foundation. Information about the methods and procedures used to arrive at the environmental data shown in an environmental statement (also called product maps) can be found on our website. 

Is your question not listed there? Ask it via the form at the bottom of the page

The viewer can be used by anyone interested in the environmental declarations published in the NMD. The viewer is therefore freely accessible on our website.

During the development of the viewer, we specifically took into account the wishes of a number of potential user groups, such as data owners, clients, LCA practicioners and consultants. From these wishes, we formed a picture of the search behaviour and desired information.




What is the NMD Viewer?

The viewer provides access to the environmental declarations published in the National Environmental Database (NMD). The NMD contains environmental declarations of building products, building installations and processes, which are used to unambiguously calculate the material-specific environmental performance of construction works in the Dutch context.

What is the purpose of the NMD-Viewer?

The aim of the viewer is to increase transparency in the NMD, while maintaining confidentiality regarding the data. The guideline for this is the document 'Gebruiksvoorwaarden invoer en gebruik data'. The viewer enables users and owners of the data to gain insight into which environmental declarations have been published in the NMD. It is also possible to use this insight to provide feedback on the data, which can improve data quality.

What kind of information can I find in the NMD Viewer?

The viewer thus displays all environmental declarations contained in the NMD. New updates are made daily, so you always get to see the most recent data.

Of category 1, 2 and 3 environmental declarations, generic data are displayed, such as the explanation of the product, the functional unit, the lifespan, the owner of the environmental declaration and the application of the product (B&U or GWW). 

For the product structure of the environmental statement, the product components are made transparent, including the element components they cover. For all environmental statements, the product ECI (Environmental Cost Indicator) is shown. The ECI is displayed by functional unit.

Many Category 3 environmental statements include a downloadable LCA report. This describes the assumptions and choices made while preparing the LCA. For category 3 environmental declarations, the environmental data can also be viewed per product component. You can choose to view the environmental data over the entire life cycle, but it is also possible to view the data per phase or module. Since 1-1-2021 a new set of environmental impact categories is being used. Because not all environmental declarations contain the new set yet, a distinction has been made between the display of 'Set 1' (according to EN15804) and 'Set 2' (according to En15804+A2)

How is the ECI score calculated and why is it important not only to look at the total score?

The ECI (Environmental Cost Indicator) score indicates the environmental impact over the life cycle of a product by adding up weighted scores for different impact categories and life stages. For more information on this weighting, see section 3.6 of the Method of Determination.

A negative ECI score may result from one impact category or life stage, and therefore does not automatically mean a favourable environmental impact in all impact categories or during all life stages. It is therefore important to look at the environmental impact per category and phase in addition to the overall ECI score to identify unfavourable environmental impacts.

For category 3 environmental declarationa, the underlying environmental burdens by impact category and life stage can be analysed to get a better understanding of where and how the environmental burden arises. This provides a deeper understanding of the overall environmental burden. Please note that for category 1 and 2 environmental declarations, this analysis cannot be performed due to the confidentiality of the underlying data. In these cases, only the overall ECI score is shown.


For whom is the NMD Viewer?

The viewer can be used by anyone interested in the environmental declarations published in the NMD. The viewer is therefore freely accessible on our website. 
During the development of the viewer we specifically took into account the wishes of a number of potential user groups, such as data owners, clients, LCA preparers and consultants. From these wishes we formed a picture of search behavior and desired information. 

What you cannot do with the NMD Viewer?

The environmental declarations and environmental data displayed in the viewer are not downloadable; the information serves primarily to form a picture of the data in our system. The viewer is not intended for creating MPG. This is due to the complex structure of the database and the importance of correctly interpreting the calculation rules. To calculate with the data, the calculation tools validated by Stichting NMD are available.

The starting point of NMD is a good design of a structure. Based on that design, an environmental performance calculation is made. There are many aspects that influence the design choices and that (in)directly affect the level of environmental performance. The viewer is therefore not suitable for comparing environmental declarations. Seemingly similar products will, depending on how the product is applied in the structure, have a different contribution to the environmental performance. With the viewer, we therefore discourage making one-to-one comparisons between environmental declarations.

How is it possible that the product I am looking for appears multiple times in the Viewer?

The data structure of the NMD follows the NL-SfB systematics and the RAW systematics for products applicable within the B&U and GWW sectors respectively. For B&U, this divides environmental declaration into elements (such as, for example, '23.2 Flooring; constructive') and for GWW into chapters (such as, for example, '32.0 Road marking').

The different elements describe all the functions a structure has to provide. In an MPG calculation, it is important that all mandatory functions of a structure are fulfilled by products.

It is possible that a product can be applied in multiple elements. In that case, the product can be found in several places in the NMD Viewer.

How to ask questions about the environmental declarations in the NMD-Viewer?

If there are questions or comments on environmental data of a specific environmental declaration, it is possible to provide feedback via our question form. If you would like to know more about the NMD and NMD Foundation, please visit our website.



Why is it called an environmental declaration and not product card in the Viewer?

The National Environmental Database (NMD) previously used the term 'product card' to describe a product's environmental data. But due to developments in the market, it was decided to replace this term with 'environmental declaration'. This environmental declaration in the NMD provides information on the environmental impact of a product or material as the product card did. It is therefore a different name, nothing else has been changed in the environmental data.

I want to use the environmental data from the NMD in my own tool. Is that possible?

Are you interested in using the data from the NMD in an application other than the validated calculation tools? We are currently conducting research into this future possibility. we would like to hear how the use of the NMD could add value within your work. You can let us know via our question form with the subject if you would like to contribute to this research.

Why is some environmental data not available in the NMD Viewer?

The viewer is not intended for making EPB (Envrionmental Performance Buildings)/ECI (Environmental Cost Indicator) calculations or comparing products. Comparison of different material choices only makes sense at the building level, because only then the correct ratios and quantities are calculated. For this we refer you to our validated calculation tools.

The NMD contains several categories of environmental data; category 1 data is proprietary data owned by manufacturers and suppliers; category 2 data is proprietary data (unbranded) owned by groups of manufacturers and/or suppliers and industries; and category 3 data is proprietary data owned by National Environmental Database Foundation. A difference between category 3 data and category 1 and 2 data is that for category 3 data, the environmental data will always be shown, while for category 1 and 2 this will only happen after permission from the data owner. If the latter is not the case, the data is not accessible (represented by a lock in the viewer). In addition, the environmental declarations whose environmental data is available will not always contain the data on circularity indicators. Also, the new impact categories ('Set 2') will not be filled in for all products. This is because this information has only been mandatory to enter since 1 January 2021.

I have an environmental declaration in the NMD that I would like to amend or contains an error, what should I do?

To adjust environmental declarations, the LCA practicioner who entered the data in the NMD must be contacted. This person can make the adjustment. Then the relevant reviewer must approve the change. The next day, the adjustment is implemented in the NMD and can be seen in the viewer.

Why are values greater than zero not known for all phases in the life cycle analysis?

A product life cycle consists of phases from production to re-use. If a phase was not investigated during the life cycle analysis, the value equals 0. It is also possible that the phase was investigated but the environmental impact is simply 0. Even then, a 0 value is shown. A final reason for a 0 value may be a category 3 environmental declaration from the old version of the NMD. In the past, the environmental impact in module D was not calculated separately, which also results in a 0 value. Stichting NMD has started a project to calculate and show Module D for this data as yet.

There is a difference between the MKI value of a category 3 product in the viewer and the product MKI as stated in the accompanying report. How is this possible?

The input of the environmental declarations uses data from the NMD process database.

Because it is updated regularly, it is possible that the ECI value of an environmental declaration differs from the ECI value given in the accompanying report. A difference in ECI value may also arise because one or more flat-rate value(s), such as end-of-life treatment scenario or transport distance, differs. As a maximum margin, we use a 5% difference on ECI value. If the deviation is larger, this will be reported to us. If you require an explanation, please let us know via our questionnaire.

Why do some environmental declarations have a lifetime of 1,000 or 999 years?

There are products that experts say will last as long as the structure in standard situations. An example is a concrete foundation pile. It is assumed that the life expectancy of these products is the same as that of the structure in which the product is used. These products are identified in the NMD by a product life expectancy of 1000 or 999 years. The guideline used for this is the SBR Catalogue (2011). Soon, 1000 years will be replaced everywhere by 999 years, because this number is clearly recognisable as deviating from logical numbers such as 100 or 1000 years. The calculation rules mean that for products with a life span of 1000 or 999 years, the product life span, which is used for calculation, is limited to the life span of the structure.

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