Radon protection guidance references

Guidance on protective measures is given in the following publications produced by BRE – (a) BR 413 Radon: guidance on protective measures for new dwellings in Northern Ireland. Note: the following matters in BR 413 no longer apply – (i) the radon survey (on which the maps are based) referred to on page 3 has been superseded – for the new survey see paragraph 3.7 of this Technical Booklet; (ii) the radon maps at the back of the publication – for the new maps see paragraph 3.7 of this Technical Booklet; (iii) the light and dark grey shading on the maps – the new maps show 5 levels of radon risk in shades of yellow to brown; three shades cover the risk level from 1% to 10%, and two shades cover over 10%; and (iv) 5 km grid squares – the new maps show 1 km grid squares. (b) GBG 73 Radon protection for new domestic extensions and conservatories with solid concrete ground floors; and