Radonmätning
Radonmätning is the measurement of radon gas in indoor air, carried out to establish whether the level exceeds the Swedish reference level. Radon is a radioactive gas that seeps in from the ground, through cracks in the structure or from certain building materials. It has no smell, cannot be seen and can only be detected by measurement.
The reference level for radon in existing homes and premises open to the public is 200 Bq/m³ as an annual mean value, set out in strålskyddsförordningen (2018:506). The reference level is not a binding ceiling, but a level that Boverket, Livsmedelsverket and Arbetsmiljöverket consider undesirable to exceed; exceedances should be remedied. For new buildings, however, a binding limit value of the same 200 Bq/m³ applies, set out in Boverket's regulation (BFS 2024:8) on hygiene, health and the environment, one of the basic regulations under Boverkets byggregler.
Under Strålsäkerhetsmyndigheten's guidance, a valid measurement must last at least two months and be carried out during the eldningssäsong (heating season), normally 1 October to 30 April. The reason is that a heated house with closed windows and doors creates a negative pressure that draws more radon-bearing soil air in through the ground. The measurement then captures the situation in which the radon level is normally highest and gives an annual average that does not understate the real level.
Responsibility for measuring lies with the owner of the building. In a flerbostadshus (block of flats), it is whoever controls the property, usually the bostadsrättsförening or the fastighetsägare, who under 3 kap. 6 § strålskyddslagen (2018:396) must optimise radiation protection so that the radon level is kept as low as reasonably possible; measurement is the precondition for knowing whether action is needed. The municipality's miljö- och hälsoskyddskontor supervises this under miljöbalken and can order a measurement if one has not already been made. If you own your own house, the measurement is your own responsibility, but here too the municipality can impose requirements if there is reason to suspect an elevated level. Strålsäkerhetsmyndigheten recommends a new measurement if more than ten years have passed since the last one, or after building work that may have affected the radon level.
When buying and selling a Swedish home, a radon measurement is one of the standard checks a buyer or their adviser should ask for documentation of, alongside the energideklaration, because a missing or old measurement result says nothing about today's level.
The Norwegian counterpart is the rules in strålevernforskriften and TEK17, but with different figures and a stricter design. Strålevernforskriften § 6 uses two thresholds for rental housing, schools, after-school care and kindergartens: an action threshold of 100 Bq/m³, which triggers a duty to consider measures, and a limit value of 200 Bq/m³, which must not be exceeded. This is a significant difference from the Swedish system, where 200 Bq/m³ is only a recommendation (referensnivå) for existing buildings, not an upper limit. Norway applies a binding ceiling equal to Sweden's new-build requirement to existing rental housing already. TEK17 § 13-5 also requires a radon barrier and preparation for pressure-reducing measures in all new Norwegian buildings. In Placepoint, Norwegian radon exposure is mapped in radon aktsomhetskart.
From Placepoint's dictionary: Radonmätning
More information: Strålsäkerhetsmyndigheten: Referensnivå og gränsvärden för radon, Strålsäkerhetsmyndigheten: Att mäta radon, Strålsäkerhetsmyndigheten: Vad finns det för krav på mätning av radon i min bostad?
English: Radon measurement (Sweden's indoor radon testing regime).
Frequently asked questions
What is the reference level for radon in Sweden?
200 Bq/m³ as an annual mean value in existing homes and premises, set out in strålskyddsförordningen. The level is a recommendation, not a binding limit, but for new buildings the same figure applies as a binding limit value.
How long should a radon measurement last?
At least two months, carried out during the eldningssäsong, normally 1 October to 30 April, so that it captures the period when the radon level is typically highest.
Who is responsible for measuring radon?
The owner of the building. In a flerbostadshus, it is the bostadsrättsförening or the fastighetsägare, with a duty to optimise radiation protection. In your own house, it is your own responsibility, but the municipality can still impose requirements.
Is there a difference between the Swedish and Norwegian radon limits?
Yes. Sweden's 200 Bq/m³ is a recommendation for existing buildings, while Norway's strålevernforskrift sets an action threshold of 100 Bq/m³ and a binding limit value of 200 Bq/m³ for rental housing, schools and kindergartens.
How do I find radon exposure in Norway in Placepoint?
Through radon aktsomhetskart, which shows which areas of Norway are likely to be more exposed to radon than others.