The following is taken from the HSE website.
Subject to Parliamentary approval, new Construction (Design and Management) Regulations 2015 (CDM 2015) will come into force on 6 April 2015.
About this guidance
This draft Legal (L) Series guidance  is on the legal requirements for CDM 2015. It’s being made available before the Regulations come into force on 6 April to help anyone who has duties under the Regulations to prepare in advance.
Please note the draft Regulations within the guidance have been amended following consultation. The Regulations and this draft Legal series guidance may be subject to change while the Regulations are awaiting Parliamentary approval. The final version of the Legal series guidance to support CDM 2015 will be available on 6 April 2015.
What will change?
Principal designer. The replacement of the CDM co-ordinator role (under CDM 2007) by principal designer. This means that the responsibility for coordination of the pre-construction phase – which is crucial to the management of any successful construction project – will rest with an existing member of the design team.
Client. The new Regulations recognise the influence and importance of the client as the head of the supply chain and they are best placed to set standards throughout a project.
Competence. This will be split into its component parts of skills, knowledge, training and experience, and – if it relates to an organisation – organisational capability. This will provide clarity and help the industry to both assess and demonstrate that construction project teams have the right attributes to deliver a healthy and safe project.
The technical standards set out in Part 4 of the new Regulations will remain essentially unchanged from those in guidance related to CDM 2007. HSE’s targeting and enforcement policy, as a proportionate and modern regulator, also remains unchanged.