Frequently asked questions

If you have any questions about the NMD, the Assessment Method and the Verification Protocol, send these to info@milieudatabase.nl.
Many frequently asked questions are included in the FAQ section. 

Do you need explanation of a term or abbreviation? Check out glossary or our list of abbreviations. 

Environmental Performance – Assessment Method

What is the difference between the Environmental Performance of Buildings method and the Environmental Performance of Buildings (MPG)?

The Assessment Method is performance oriented, not solution oriented and therefore sets no requirements on construction method and technology. Clients and contractors can use the method to make agreements about a construction project’s quality levels, with total design freedom and space for innovative solutions.
The Energy Performance of Buildings (EPB) is an important benchmark for a building’s sustainability. The lower the EPB, the more sustainable the use of materials. The EPB is an objective resource during the design process and can be used in a Design Brief to record the result of a design process. An EPB calculation uses environmental information from the NMD.

What is the shadow price methodology?

Scores for environmental impact categories need to be weighted and combined to arrive at a single indicator for environmental impact. This weighting takes place using the shadow pricing method: multiplying the characterised impact scores by the corresponding shadow price, which is the highest permissible cost level for the government (prevention cost) per unit of emission control.

Why is the appendix "Overview of the scope of a building work calculation for the different user functions" not complete?

The Assessment Method only indicates the methodology of how the environmental performance of a building or structure should be calculated. It does not indicate the set of construction products and construction installations over which the calculation should be made. Nor does it indicate how the environmental performance of a building should be divided over several use functions in that building. The regulations that refer to the Assessment Method for calculating the requirements set in the relevant regulation (e.g. Building Decree or BREEAM) indicate the collection of construction products and building installations over which the calculation should take place. This is always a description and not an exhaustive list, as there are always products that do not appear in the list. The overview of the scope is therefore only included for information as appendix to the Assessment Method and does not claim to be a complete overview, because the components that do or do not need to be included differ per regulation.

What is the difference between NEN-EN 15804 and the Assessment Method for Environmental Performance of Buildings?

The Environmental Performance Assessment Method for Construction Works is based on NEN-EN 15804 Sustainability of Structures – Environmental Declarations – Basic Rules for the Construction Products Product Group. The Assessment Method models NEN-EN 15804 to the Dutch context and to Dutch construction methods.

Which version of the Assessment Method should I use?

The Assessment Method is applied in both public and private law. Public law means that it is referred to in legislation and regulations, in this case the 2012 Building Decree and the 2012 Building Decree Regulations. This legal reference refers to the calculation rules in chapter 3 and not to the methodical requirements from chapter 2.
Since the Environmental Performance Assessment Method for Construction Works 1.0 was published on 1 July 2020, during 2021 chapter 3 of this will replace chapter 3 in the current Assessment Method (v3.0 January 2019). This implies an amendment to article 3.1 of the Building Decree Regulation. Private parties who use the Assessment Method can determine for themselves which version of the Assessment Method they prescribe. See also: Which version of the Assessment Method applies for what? (NL)


I want to deviate from default building life in my calculation. What are the guidelines for this?

No specific building service life expectation is indicated in the Environmental Performance Assessment Method for Construction Works; clients and contractors can decide to indicate this. However, many default values are mentioned, these being 75 years for dwellings and 50 years for utility buildings. Construction practice needs a standardised Life Cycle Assessment of buildings in the form of a well-founded deviation from the default value in order to benchmark the environmental performance of buildings and consciously steer towards a long(er) or short(er) life cycle, as early as the design stage. Commissioned by the Ministry of the Interior and Kingdom Relations, W/E adviseurs prepared the ‘Specific Building Service Life Guideline’ report, which serves as a guideline for the voluntary use of a similar standardised life cycle assessment. If there is sufficient support, this guideline can be included as normative in the Environmental Performance Assessment Method for Construction Works.

What is the difference between an MPG calculation and Dubokeur?

The DUBOkeur® demonstrates which products (for the construction, civil engineering or interior design sector), raw material, installation or home are the most environmentally friendly choice. This is demonstrated using an environmental Life Cycle Assessment produced by the Dutch Institute for Building Biology and Ecology (NIBE). Having a quality mark such as DUBOkeur® is not incorporated in the Building Decree. Requirements are, however, set on the Energy Performance of Buildings (EPB).

Environmental performance – Environmental performance calculation

Why do we have more environmental indicators in the Netherlands than in other EU countries?

A Life Cycle Assessment (LCA) results in an environmental profile. Until end 2020, this profile comprised 11 environmental impact categories in accordance with EN 15804, but as EN15804 was amended in 2019 and its methodology was synchronised with the LCA methodology from the PEF (Product Environmental Footprint), from 1 January 2021 and in line with EN15804+A2, the profile comprises 19 environmental impact categories. These are more than is required in Europe. Stichting NMD will issues a document explaining the differences in the near future.

How is a change in understanding of environmental impact handled?

The list of environmental impact categories from the Assessment Method indicates the environmental impact of the product being studied. This list is agreed at European level in the EN 15804+A2 standard. The Assessment Method will be amended in the event of changes to this standard as a result of advancing scientific insight.

I have a question about the Environmental Performance Calculation of my design. Where can I go?

The Environmental Performance Calculation Guide, July 2020 version contains several interpretations and design issues for calculating the energy performance of buildings. The guide largely follows the context of the threshold for environmental performance as stated in the Building Decree, which came into force on 1 January 2018.

To which buildings does the MPG apply?

The Energy Performance of Buildings (EPB) is mandatory for every environmental permit application. The EPB indicates the environmental impact of the materials used in a building. This concerns new office buildings (larger than 100 m²) and new-build homes.
As of 1 January 2018, a limit value of 1.0 applies to the EPB. The environmental performance for new homes (not for offices) was tightened from 1.0 to 0.8 on 1 July 2021. The aim is to gradually set tighter requirements until these are halved by 2030.
You can find the most accurate information about the decisions taken and the tightening of requirements on Netherlands Enterprise Agency website.

What is the difference between NEN-EN 15804 and the Environmental Performance Assessment Method for Construction Works?

The Environmental Performance Assessment Method for Construction Works is based on NEN-EN 15804 Sustainability of Structures – Environmental Declarations – Basic Rules for the Construction Products Product Group. The Assessment Method models NEN-EN 15804 to the Dutch context and to Dutch construction methods.

Do tiny houses also fall under the Building Decree? In particular, in the context of the rules concerning sustainable building?

The tiny house concept is not defined in the building regulations. If the tiny house is a building, that building will have to meet the requirements of the 2012 Building Decree (Article 1b of the Housing Act). A building or component intended for housing is considered to have a residential function, and must comply with the requirements set for this in the Decree. This also applies to regulations in the context of environment. According to article 1.3 of the 2012 Building Decree, it is possible to deviate from the 2012 Building Decree regulations on the basis of equivalence. An applicant for an environmental permit will have to demonstrate to the satisfaction of the competent authority (the municipality) that a solution offers equivalence as referred to in Article 1.3. 

Should external facilities be included in the MPG calculation required by the Buildings Decree?

The system demarcation for environmental performance extends to the plot boundary: in the Building Decree, external energy supply installations as well as sewerage connections form part of environmental performance. As illustration, please see the 2012 Building Decree Information Sheet relating to sewerage and municipal water management tasks (NL). The illustrations in the Information Sheet clarify how far the provisions extend within the plot boundary and must therefore be included in the building’s environmental performance calculation.

How should external energy supply systems be included in the MPG calculation required by the Buildings Decree?

Installations for external energy supply (such as the connections for gas, electricity and/or heat as well as energy infrastructure and central systems for generation/conversion) must be included in the environmental performance calculation. Such systems will need to be mentioned in the energy performance calculation and an equivalent in terms of material use will need to be included in the environmental performance calculation. The National Environment Database includes so-called default values for this, which are determined by entering the calculated building-related energy consumption in the calculation.

I am looking for reference buildings for an impact and monitoring study. Does the NMD have them?

In cooperation with LBP Sight, W/E adviseurs conducted the ‘Materialisation reference buildings (NL)’ study for Stichting National Environmental Database, in which fully materialised reference buildings were recorded. This set of reference buildings was developed to conduct valid impact and monitoring studies, with a view to possible changes in the EPB. This set is public so that calculations can be verified and reproduced. > More about Environmental performance

How are PV panels included in the MPG calculation?

Building applications should be subject to an integral and cohesive assessment. That is why the Building Decree calculations need to be consistent. The square metres of PV panels used in the BENG calculation (energy performance) should also be included in the EPB calculation (energy performance). This means that the calculations based on which the environmental permit is granted always use the same square metres of PV panels. The Building and Housing Inspectorate monitors this.
As soon as the Quality Assurance Act for Construction (Wkb) comes into force, the quality assurance agency will supervise this. Together with the competent authority file, the competent authority receives the quality assurance agency’s declaration that the project complies with the Building Decree (after 1 January 2022 the Building Environment Decree (BBL)) and the BENG and EPB calculations.
More solar panels may be installed on the roof than indicated in the environmental permit for the building, provided the conditions set out in the Environmental Law Decree for the permit-free installation of PV panels are met for that surplus.

How does one go from an LCA/EPD to an MKI/MPG?

After drawing up an LCA and EPD these data can be added to the NMD, after verification. The environmental data in the NMD are used by several private companies that have developed calculation tools to make an Environmental Cost Calculation (ECI) or EPB calculation. ECI and EPB values can therefore only be made transparent using the calculation tools.

Environmental Performance – Calculation tools

Does the NMD have its own calculation tools?

No, calculation tools are online proprietary calculation software used to calculate the environmental performance of construction works based on environmental data in the NMD. Stichting NMD has formulated calculation rules to clarify and control how the Assessment Method should be converted into a digital instrument. The rules ensure that the calculation tools use a uniform calculation, which provides an unambiguous result for the energy performance of buildings.

I am a calculation tool owner and would like to use the NMD. What do I need to do?

Before receiving the ‘validated’ stamp, the calculation tools must be verified using a validation procedure; the NMD software validation guidelines. Stichting NMD uses this validation procedure to check whether the calculation rules have been used and whether the Assessment Method and the NMD have been implemented properly in the software.
A one-off registration fee of € 15,762 applies to the use of the entire database plus an annual licence fee of € 2,589 for NMD use and updates. The stated amounts exclude VAT and apply from 1 January 2021 to 1 January 2022.

Environmental Performance – Circularity

How does NMD respond to the increasing interest in circularity?

As well as data on the environmental impact of construction products (environmental performance), from 1 January 2021 the NMD will also include data on the underlying parameters from a Life Cycle Assessment (LCA) report, such as material flows in kg (including secondary material input and output, material for recycling, material for reuse), the amount of renewable energy used and water consumption in the chain.
NMD is also informed of the latest developments in this area and we are involved in various research studies.

Does the MKI/MPG value give an indication of the circularity of a product?

The ECI/EPB as value of the environmental performance of buildings does not, in itself, give any indication of a product’s circularity. The ECI/EPB value is a 1-point score of a building/structure’s environmental performance, assessed in line with the Environmental Performance Assessment Method for Construction Works. This value therefore provides an indication of the effect of the circular strategy on environmental performance. Stichting NMD is currently conducting research into indicators of circularity so that it can express circularity numerically using an LCA report in addition to the ECI/EPB value.


Why are both brand-related (category 1) product cards and averages (brand-unrelated, category 2 and 3) used?

The starting point of the NMD is to work with as many propriety (category 1) product cards as possible. Besides challenging companies to innovate, proprietary product cards best represent actual environmental impact. 

However, the NMD currently also contains many averages (category 2 and 3) due to a lack of data supplied by manufacturers. 

The NMD website and documentation speak of database version and data version. What is the difference?

The ‘database version’ refers to the system version and relates to the system updates behind the data stored in the NMD. The ‘data version’ refers to data updates – adding, editing or deleting data. In the past the data and system version ran in parallel: With the release of NMD2.3, both the data and the system are updated. In the new NMD3.0 system, these two are separated. The data version has been time-dependent since that time. As the data are updated every 24 hours, a new version of the data appears every 24 hours. The system version remains the same.

What is the difference between the National Environmental Database and the process database?

Stichting NMD manages both the National Environmental Database (NMD) as well as the NMD Process Database. The NMD is a database filled with product cards. This is the database that is used by the calculation tools to produce ECI and EPD calculations. The NMD Process Database is used as source (to draw up LCAs) for the data included in the product cards in the NMD.

Environmental data

How long does it take for my product to appear in the NMD?

The lead time of this process is highly dependent on the Life Cycle Assessment and will differ per product and LCA expert. As soon as the environmental data are entered a recognised LCA expert will check the entry. The environmental data will then be published in the NMD. The steps to be taken can be found on our website. More information about registering data

About us

What is the NMD and what does it do?

Stichting NMD maintains and safeguards system quality with the Environmental Performance Assessment Method for Construction Works and a neutral, independent environmental database that stores environmental data on construction materials, construction products and building installations. They do this in coordination with and with the commitment of all stakeholders.


What is a background process?

A background process that impacts a product from a producer or supplier, but over which the producer or supplier has no direct influence and that takes place elsewhere in the chain; the production of electricity or a raw material, for instance.

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