Buildings and radon.

This guide is divided into four sections, which draw together different areas of BRE radon-related research. It supplements existing guidance. Sump systems are usually very effective at reducing indoor radon levels. The first part of the guide describes the benefits of passive sump systems, ie systems that are not fan-assisted. The second part shows how a single fan-assisted system can be used to treat several adjoining houses. Compared to installing several separate systems, a communal system of this type is quicker and cheaper to install and causes less disruption. Other sections tell you how to safeguard against the spillage of combustion products when using a radon remedial system, and how to protect new extensions and conservatories against the entry of radon.