The relative contributions of bedrock geology, radiometric uranium, till permeability and surficial geology were assessed as predictors of radon in indoor air in the Halifax Regional Municipality (HRM), NS, Canada. Bedrock geology and radiometric uranium were statistically significant predictors (14.4%) of indoor radon, based on available indoor radon data. Permeability was not among the predictors, which was surprising given its importance in past studies. In a follow up field analogue study done in laboratory columns, the permeability and diffusivity, as gas transport mechanisms, were found, as suspected, to be important drivers on the concentrations of radon-222 detected. Given the variable thickness of till in the HRM (< 0.5 m to > 3 m), these experiments highlighted the significance of till thickness, composition, and permeability in predicting the radioactive radon-222 potential.