Knowledge base · method

Basic or detailed method?

Two ways to determine an energy label under NTA 8800. This is the difference and how to choose.

In short

The essentials at a glance

With the basic method the adviser uses standard (default) values when there is no evidence of the actual properties of constructions and installations. With the detailed method those properties are determined precisely, such as the U-values of individual constructions and heat loss at junctions. The detailed method is more accurate and mandatory for new builds.

Basic method: default values unless proven
Detailed method: actual properties, more accurate
New builds: detailed method
Price at Hasibo: basic from €330, detailed from €425

The difference in practice

	Basic method	Detailed method
Values	Defaults unless demonstrated	Actual properties per construction
Accuracy	Good for common situations	Highest
Suited to	Existing homes for sale or rental	Renovations, complex buildings, new builds
Adviser	Basic or detailed adviser	Detailed adviser
Price (apartment)	€330	€425

When do you choose the detailed method?

After a major renovation with lots of insulation or new installations
For homes that deviate from standard building types
If you are just on the edge of a label class and want the most accurate result
As the basis for tailored energy advice

Tip: with the basic method too, the adviser may deviate from default values if you have evidence such as a product declaration. Keep invoices and product data for insulation and installations.

Frequently Asked Questions

Answers to the questions we are asked most about this topic.

1. Does the detailed method always give a better label?

Not always, but often for homes that perform better than the default values assume, for example after insulation. The result is more accurate either way.

2. Which method do I need for a sale?

For the sale of an existing home, a label under the basic method is sufficient.

Last updated: 7 October 2026 · by Hasibo Ingenieurs & Adviesbureau

Sources: RVO — Differences between NEN 7120 and NTA 8800 (Dutch)