AGES provides a radon map for all of Austria. Colourful shading, municipal boundaries, a few numbers. Looks clear — but what does the map actually tell you? And what does it not show? Here we explain how to read the map correctly and why it alone is not sufficient.
What the Radon Map Shows
The AGES radon map is based on radon potential — a combination of geological data and actual measurements in buildings. Each municipality receives a colour:
- Green: Low radon potential
- Yellow: Medium radon potential
- Orange/red: High radon potential
The resolution is at municipal level — each municipality has exactly one value. Based on this data, Austria has designated over 100 municipalities as radon protection zones (pursuant to Radiation Protection Act 2020, § 36). In these municipalities, special requirements apply for new buildings and workplaces.
→ View the interactive radon map
What the Colours Actually Mean
Green municipality means: lower radon values on average. It does not mean "no radon". Even in green municipalities there are houses with values above 300 Bq/m³.
Yellow municipality means: medium potential. A measurement is worthwhile for old buildings with basement use or ground-floor apartments.
Orange or red municipality means: high potential. A measurement is strongly recommended — especially if you spend a lot of time in ground-level rooms.
Radon protection zone means: legally defined zone. For new buildings, a radon-proof floor slab is mandatory. For workplaces in basement and ground-floor rooms, measurement is compulsory.
What the Map Does Not Show — and That Is the Crucial Point
The map shows average values per municipality — not individual houses. And that is precisely the problem:
Local geology varies within a municipality. Your house may stand on a granite block, the neighbouring house 200 metres away on gravel. Completely different radon values — same colour on the map.
Building construction is completely absent. Age and condition of the floor slab, basement construction, cracks in the foundation, pipe penetrations — all of this influences how much radon enters the building. The map knows nothing of this.
Usage patterns play a role. How often do you ventilate? Are basement windows open or closed? This also affects the actual concentration in your rooms.
From our experience: we regularly measure values above 300 Bq/m³ in green municipalities — and low values in red ones. The map gives you an orientation, nothing more.
When to Measure Even in a "Green" Municipality
- Old building with basement rooms used as living space — hobby room, home office, children's room in the semi-basement
- House on a slope or on granite bedrock — geologically higher potential, even if the municipality is on average green
- Home purchase — regardless of which colour on the map. Radon is part of the standard check. (→ Pollutant check home purchase)
- Kindergartens, schools, care homes — anywhere people spend many hours per day in ground-level rooms
How a Measurement Works
Radon is measured with passive dosimeters — small capsules that lie in the affected rooms for at least 3 months. Ideally during the heating period (October to March), when less ventilation occurs and values are at their highest.
One dosimeter costs €30–€50. We advise you on where to place them and how to interpret the results.
Further reading: → Radon in Austria and → Radon measurement: How long, where, how many?
When You Should Get in Touch
You have looked at the map and want to know what it means for your specific house? You are planning a home purchase and want to have radon measured? You live in a radon protection zone and want certainty?
15-minute initial consultation, free of charge.