What is a principal designer and what are their responsibilities?

The CDM principal designer is the designer with overall control of health and safety during the pre-construction phase. There can be many designers, but only one principal designer. The principal designer is appointed by the client, or if one is not appointed the client assumes the role of PD. The PD has responsibility for preparing and providing the pre-construction phase information, and planning, managing and monitoring the pre-construction phase health and safety arrangements. This includes identifying and controlling risks during project preparation, and ensuring other designers carry out their duties.