The proposed revised Part H2, of the Building Regulations (England and Wales), and the proposed new Part M of the Technical Standards for compliance with the Building Standards (Scotland) Regulations 1990, as amended, both make reference to reed bed systems for treating domestic wastewater. This Guide provides guidance to support building regulation requirements, describing typical applications and current accepted minimum design specifications for reed beds treating settled domestic wastewater. Part 2 sets out the design and construction parameters, and maintenance requirements. It explains the role of the plants in a reed bed and describes a test for determining the suitability of sand to be used in the beds. 8 pages.