CDM Principal Designer Fee 2025/26

The Principal Designer (PD) is appointed by the client under the Construction (Design and Management) Regulations 2015 (CDM 2015) on notifiable projects. The PD coordinates health and safety during the pre-construction phase — managing design risks, ensuring designers comply with their CDM duties, preparing pre-construction information for the Principal Contractor, and maintaining the health and safety file. The PD must be a designer with the skills, knowledge and experience to fulfil this role — typically the architect or a specialist CDM consultant.

A Principal Designer must be appointed on all notifiable projects — those lasting more than 30 working days with more than 20 simultaneous workers, or exceeding 500 person-days of construction work. The appointment must be in writing and should be made as early as possible in the design process — ideally at the start of RIBA Stage 2. Non-notifiable projects (the majority of small domestic projects) do not require a PD appointment, but clients still have duties under CDM 2015 regarding pre-construction information.

Yes — on most residential and smaller commercial projects, the architect acts as Principal Designer. However, the architect must have the competence to fulfil the PD role and this should be explicitly agreed in their appointment letter. On larger or more complex projects, a specialist CDM advisor or dedicated PD consultant may be more appropriate, particularly where there are many specialist designers, complex interfaces, or significant legacy hazards such as asbestos or contamination. The fee for PD duties should be separated from the design fee in the appointment.