A building with high levels of radon gas in the indoor air has a negative effect on the users of the building. Radon in buildings is one of the most common cause to lung cancer in Sweden today, which is why the Boverkets byggregler have set a limit value of 200 Bq/m3 for indoor air in new buildings. The limit value is twice as high as the limit value set by WHO, due to the high uranium levels in Sweden. The soil conditions in Sweden vary, which leads to the problem with the concentration of radon in the soil being different in different geographical locations in Sweden. The thesis has examined routines regarding radon in the soil at the design stage at Skanska in Helsingborg to highlight the risks of the municipality designating the area as a low-risk area. The methods used in this thesis consists of a survey, interviews and examination of documents and geodata. The survey and interviews were conducted with employees at Skanska in both Helsingborg and Uppsala, in order to make a comparison between two areas where the radon problem differ. The results show that there are gaps in knowledge about radon among the employees in Helsingborg, due to lack of experience. If the municipality does not set requirements regarding radon in the inspection plan, Skanska will not do so either. The results also show from measurements that there are areas in Helsingborg that should be considered a high-risk area for radon. One conclusion for the thesis is that regular internal education regarding radon can be beneficial in an area that is considered a low-risk area, as there is a lack of practical experience. Another conclusion is that it is misleading to generalize an area as a low-risk area, as measured values from radon examination in soils show local differences. A recommendation is therefore to always perform a radon examination before a new building is constructed.