Yes. Radon protection measures are required for new dwellings across the country under Part C of the building regulations, with a radon barrier installed beneath the floor and, in designated High Radon Areas, additional provision such as a standby radon sump. The exact requirement is set out in Technical Guidance Document C.
Technical Guidance Document C sets out radon protection for new buildings. A radon-resisting membrane is installed as a continuous barrier under the floor and sealed at joints, service penetrations and around the perimeter, so that soil gas cannot enter the building. Careful detailing is more important than the material itself, since most failures happen at penetrations and laps.
In areas identified as High Radon Areas on the EPA map, additional measures are specified, typically the provision of a standby sump that can be activated later if a test shows elevated radon. Installing the sump at construction stage is inexpensive compared with retrofitting one.