Custom NMD integration for environmental performance
For new-build projects, the Besluit bouwwerken leefomgeving (Building Decree) sets a maximum environmental performance (MPG) per use category. You determine the MPG using the Bepalingsmethode Milieuprestatie Bouwwerken (the Dutch environmental performance assessment method), with environmental data from the Nationale Milieudatabase (NMD, the Dutch national environmental database) and in a calculation tool validated by Stichting NMD. From 1 July 2026, version 2.0 of the method, the A2 set and stricter requirements apply. The quantities are usually already in your cost estimate or BIM model. Appfront builds the integration that links them to the right environmental declarations and prepares the input for your calculation tool.
What is an integration between your construction data and the Nationale Milieudatabase?
An NMD integration connects the data of a construction project to the Nationale Milieudatabase. This database contains environmental declarations for building products and materials, managed by the independent Stichting NMD. Each declaration describes a product with basic details such as name, service life and functional unit, supplemented with environmental data from a life cycle assessment. The NMD divides the declarations into three categories: category 1 for brand-specific data from a manufacturer, category 2 for industry-wide data, both verified by an independent third party, and category 3 for generic data from the NMD itself. For category 3, the assessment method applies an uplift factor of 30%, which often makes a verified declaration more favourable.
The calculation itself takes place in a calculation tool. This is private software that Stichting NMD validates, twice a year, and only validated tools may be used for official calculations. According to the NMD, once a tool holder has been validated, it gets access to the full database through an API, under a non-disclosure agreement, because the environmental data is confidential. For exploration, the NMD also offers a Cat. 3 Viewer API in beta. In practice, an adviser copies the quantities from the cost estimate or the model into the calculation tool, element by element, and does so again with every design change.
We build custom because every firm and company works with different sources. A contractor calculates from their estimating package, an engineering firm from an IFC model, a manufacturer wants to keep track of their own declarations and their expiry dates. The integration assigns elements and quantities to environmental declarations, shows where category 3 is still being used, and prepares the input in the form your calculation tool can read. Exactly what that input looks like depends on the tool you use; the official result stays there.
From your sources
Cost estimate, BIM or articles.
Per element
Linked to a declaration.
Ready to calculate
In your calculation tool.
How we build your integration between your construction data and the Nationale Milieudatabase (NMD)
We start with your calculations: which calculation tool you use, where the quantities currently come from, how you link elements to environmental declarations and which design variants you compare. Then we build the first integration for a single source, such as your cost estimate, and compare the result with a calculation you previously made by hand. Your adviser uses it on one project. Other sources, comparing variants and flagging category 3 declarations follow once that goes well. After that, we keep the integration up to date when the Determination Method or the database changes.
Sources, tool, variants.
Checked against an earlier calculation.
More sources and variants.
Go-live, monitoring, and maintenance when things change.
What an integration between your construction data and the Nationale Milieudatabase actually does
The components below appear in almost every NMD integration. Which ones you need depends on your sources and on the calculation tool you use.
Retrieving
From cost estimate and BIM.
Allocate
Element to declaration.
Category
Where category 3 matters.
Input
For the calculation tool.
Variants
Side by side.
Due date
Declarations kept up to date.
Who we build an integration between your construction data and the Nationale Milieudatabase for
The integration is intended for anyone who regularly produces MPG calculations, or has them produced, or who, as a manufacturer, has many environmental declarations in the NMD. The more projects and variants, the more it delivers.
Advisers
Less re-entering per project.
Contractors
From your own cost estimate.
Manufacturers
Add your own declarations.
Software vendors
Working with NMD data.
Technology and integrations
This page is about linking construction data to the Nationale Milieudatabase for environmental performance. If you want to import or exchange IFC models in general, see our page on the IFC integration. For your cost estimating software, see our page on the Ibis cost estimating integration, for BIM software itself our page on BIM software, and if you want to substantiate sustainability claims about your product, see our page on the claim substantiation file. You can read about our approach on building software.
Why Appfront for your integration between your construction data and the Nationale Milieudatabase?
An element missing from the calculation, a generic declaration where a verified one was available, or a calculation that no longer matches the model after a design change, produces an MPG that does not match the building. That is what we build around: quantities from your own sources, visibility per element of which declaration was used, and every version traceable.
Less re-entering
From cost estimate and model.
Visible choices
Declaration per element.
Fast variants
Every change kept.
Security and privacy in an integration between your construction data and the Nationale Milieudatabase
According to Stichting NMD, environmental data from the NMD is confidential and may not be shared with third parties. The integration therefore works with the data and access that you or your calculation tool legitimately hold, and does not share NMD data outside your organisation. Clients' design data is visible only to the people working on the project.
The integration runs in a European data centre, with encrypted connections and storage and daily backups. Whoever creates or changes an assignment is recorded by name and time, so that for every calculation you can trace which declaration was used for which element.
Frequently asked questions about an integration between your construction data and the Nationale Milieudatabase
Questions that advisers, contractors and manufacturers ask before they get started.
An integration that assigns the quantities from your cost estimate, BIM model or product administration, element by element, to environmental declarations in the Nationale Milieudatabase (the Dutch National Environmental Database). This gets the input ready for your calculation tool without having to copy everything over by hand.
No. Official calculations may only be carried out in a calculation tool that Stichting NMD has validated. The integration prepares the input and puts results side by side; the official result comes from the calculation tool.
According to the NMD, access to the full database via an API is granted to an instrument holder after validation, under a non-disclosure agreement. For exploration, a Cat. 3 Viewer API is available in beta. Which route suits you depends on your role and the instrument you use.
Category 1 is brand-specific data from a manufacturer, and category 2 is industry-wide data; both are verified by an independent third party. Category 3 is generic data from the NMD itself, to which a 30% uplift factor applies. The integration shows you where you are still calculating with category 3.
According to the NMD, version 2.0 of the Determination Method has been designated in the Omgevingsregeling (Environment Regulation), and calculating with the A2 set is now mandatory. At the same time, the MPG requirements have been tightened and, for the first time, requirements apply to non-residential buildings such as schools and shops.
Yes. A manufacturer can track, per product, which environmental declaration is in the NMD, in which category and when it expires. The NMD uses an expiry period of five years, after which a declaration must be updated by the LCA author.
For consultancies and companies that frequently produce MPG calculations or compare many variants, and for manufacturers with many declarations. If you only occasionally run a calculation for a single home, working in the calculation tool itself is often enough.
Your MPG input from your own estimate or model?
Tell us which calculation tool you use, where the quantities currently come from and how many calculations you run. We will show you how an integration can simplify that.