NTA 8800 explained: the calculation method behind the BRL 9500 energy label
NTA 8800 is the Dutch calculation method for the energy performance of buildings. The result of that calculation appears on the energy label. An EP adviser works with it within the rules of BRL 9500. You can find more about the energy label at RVO .
That is the difference between the two. NTA 8800 sets out what you calculate. BRL 9500 sets out who may calculate, and how that person and the company work.
BRL 9500 regulates the adviser. NTA 8800 regulates the calculation. Without an adviser there is no label, and without NTA 8800 there is no figure that may appear on the label.
What exactly does NTA 8800 calculate?
NTA 8800 translates the features of a building into one figure: the energy performance. These features include, for example, the insulation of the roof and walls, the windows, the heating and hot water installations, and the ventilation. The adviser collects this data during a survey of the building. The calculation software then carries out the calculation according to NTA 8800.
Take bakery De Wit, a fictional business premises built in 1978. In 2015 the roof received extra insulation, and in 2024 a heat pump was installed. The adviser records this data. The software uses NTA 8800 to calculate how much energy the premises use, and that figure appears on the label.
So this is a calculation based on the construction and the installations, not a measurement of your meter readings.
Which version of NTA 8800 applies?
RVO refers to “the designated version of the NTA”. This means the version that the government designates for energy performance. It is therefore important to ask your adviser which version they use for your building.
According to RVO, the energy label has had a new design since 29 May 2026. That is a good moment to check whether your label still uses the old layout.
The calculation software must match the designated version of NTA 8800. If an adviser uses outdated software, the result may not match the current rules.
How does NTA 8800 relate to BRL 9500?
Three documents work together. They complement each other, and each has its own role.
| Document | What it regulates | Who it applies to |
|---|---|---|
| NTA 8800 | The calculation method for energy performance | Calculation software and adviser |
| BRL 9500 | How the adviser and the company work, and how they are checked | Advisers and certified companies |
| BRL 9501 | The attestation of calculation software, matching the designated NTA version | Software suppliers |
According to RVO, a detailed calculation for an environmental permit must be made by a BRL 9500 detailed adviser, using BRL 9501-attested software. That software must match the designated version of NTA 8800.
The basic method and the detailed method
NTA 8800 has two ways of calculating: basic and detailed. Which one you may use depends on your adviser competence.
A basic survey is carried out when a detailed survey is not possible, because detailed input data is missing. A detailed survey, by contrast, uses detailed input data about the building.
Detailed advisers may do everything that basic advisers may do. In addition, they may calculate using the detailed method, including for new builds. According to RVO, this is needed for an environmental permit and for handover.
| Competence | Building type | May use the detailed method? |
|---|---|---|
| EP-W/B | Homes | No |
| EP-W/D | Homes | Yes |
| EP-U/B | Non-residential buildings | No |
| EP-U/D | Non-residential buildings | Yes |
An adviser who only surveys existing homes needs EP-W/B. An adviser who calculates new offices for a permit needs EP-U/D. You can read more about this difference on basic versus detailed survey.
Why the adviser must be able to do the calculation
The adviser produces the label, not the company itself. To do this, the adviser must hold the correct EP competence. The requirements for the training and the exam are set out on the EP adviser exam page.
After the survey, the adviser registers the label in EP-Online , the national database. Read on EP-Online registration to see what you need for that.
For the owner or landlord, this means: ask the adviser for their certificate and for the version of the calculation method and the software. That way you know the label was produced correctly.
Frequently asked questions
Is NTA 8800 the same as the energy label?
No. NTA 8800 is the calculation method. The energy label is the document that shows the result. The outcome of the calculation determines the letter on the label.
Can I calculate with NTA 8800 myself?
You can read the standard, but for a label you need a certified adviser and approved software. A label that you produce yourself is not valid.
Does a new-build project use a different version from an existing building?
It can. Ask your adviser which version they use for your project.