Radon Protection Required by Risk Level

Table 3.1 Radon Protection Required Radon risk shown on the radon map referred to in para 3.7 (probability of radon in a dwelling exceeding the Action Level) | Radon protection required 0 – 1% | No protection required 1 – 3%, 3 – 5% and 5 – 10% | Zone 1 measures (radon membrane required) 10 – 30% and greater than 30% | Zone 2 measures (membrane plus provision of subfloor depressurisation e.g. a sump and stub duct) Note: (1) BR 211 Radon: publication (referred to in para 3.11) provides guidance on determining the level of protection that is appropriate, along with details of protective measures for new buildings, and extensions etc.