Is NBN D50-001 mandatory?

It is the technical reference used within EPB requirements for residential ventilation. How it applies, which cases are covered and what documentation is required fall under your region's regulations and your project type. On an EPB-regulated project, the appointed EPB reporter produces and justifies the calculation.

My home dates from 1960, does this apply to me?

There is no retroactive obligation to fit an existing home. The standard nonetheless remains the right technical yardstick for judging whether your current ventilation is adequate, and it becomes practically unavoidable as soon as you renovate heavily, because the building's air-tightness will increase.

How do I know what my ventilation should extract?

Our calculator applies the 3.6 m³/h per m² rule and the per-room limits to the floor areas you enter. It gives a reliable order of magnitude in seconds. For an EPB file, refer to your EPB reporter's official calculation.

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What flow rates does your home need?

NBN D50-001 derives a room's flow rate from its floor area: 3.6 m³/h per m², constrained between a minimum and a maximum specific to the room type. Enter your rooms below.

Room type
Floor area (m²)
Supply
108m³/h
Room type
Floor area (m²)
Supply
50m³/h
Room type
Floor area (m²)
Supply
40m³/h
Room type
Floor area (m²)
Extract
50m³/h
value raised to the standard's minimum · 43 m³/h
Room type
Floor area (m²)
Extract
50m³/h
value raised to the standard's minimum · 22 m³/h
Room type
Floor area (m²)
Extract
25m³/h

Total supply air: 198m³/h
Total extract: 125m³/h

Your need for fresh air (living rooms) and for extraction (wet rooms) differ a lot. A heat-recovery unit supplies and extracts the same amount of air: you therefore size it on the larger of the two totals.

Indicative result, provided for information. For a project under EPB regulations, the reference calculation is the one produced by the EPB reporter appointed to your project.

And in reality, does your system reach those values?

Want to know whether your ventilation really reaches these values? Take the “airflow check” option (20 €) when booking your service: we measure the air at every valve to spot any anomaly and confirm that everything is in order.

Book Ventilation flow rates: what NBN D50-001 requires

What your region requires

Flow rates are calculated to NBN D50-001 everywhere. What changes between regions is how compliance is verified on a project.

Region	What applies	Who is responsible
Brussels-Capital Region	Ventilation provisions required in new build and certain renovations fall under Brussels EPB regulations. Flow rates are calculated to NBN D50-001.	The EPB adviser appointed to the project
Walloon Region	Hygienic ventilation is part of Walloon EPB requirements, with minimum flow rates set by room area and use, in line with NBN D50-001.	The project's accredited EPB officer
Flemish Region	Flanders goes further than the other two regions: since 2016, every EPB-regulated project requires an accredited ventilation reporter, separate from the EPB reporter. They produce a pre-design before works, then measure actual flow rates after installation.	An accredited ventilation reporter, alongside the EPB reporter

Indicative information, applying to projects governed by EPB regulations. Procedures change and have exceptions: check with your region's authority, linked below.