Do you know...The CDM Requirements When Hiring Professionals

Published on 23rd June 2026

Do you know… is our brand new quickfire series that quickly answers some of the ‘must know’ topics that impact your professional practice.

Under CDM, do clients have a duty to engage professionals who belong to a professional body?

A common misconception in the design and construction industry is that the Construction (Design and Management) Regulations 2015 (CDM) require clients to appoint designers or contractors who are members of a professional body. The answer isn’t quite so simple, but there’s an important distinction every interior designer should understand.

Under CDM, clients have a legal duty to appoint competent professionals. This means anyone they engage must have the skills, knowledge, experience, and organisational capability to carry out their role safely and effectively.

For interior designers, this is where professional body membership becomes not just relevant, but incredibly useful in attracting clients. The regulations do not explicitly state that a designer must belong to an organisation like the BIID but it can be a strong indicator of competence. To be a Registered Interior Designer, for example, you must pass a professional review which demonstrates a degree of professional standards.

Professional body membership often demonstrates:
Commitment to industry standards
Ongoing Continuing Professional Development (CPD)
Adherence to a code of conduct
Access to best practice guidance
Professional accountability

For clients, appointing an interior designer who is part of a recognised professional body can provide reassurance that they are working with someone who understands both design excellence and is working competently and professionally.

For designers, it’s also worth remembering that CDM responsibilities begin much earlier than many realise. If you are influencing layouts, specifying materials, or affecting how a space is constructed or altered, you may well be acting as a designer under CDM, and with that comes legal duties. Unsure of your responsibilities? Designers can rewatch the webinar ‘CDM Regulations 2015- your responsibilities as designers explained’ here.

The takeaway

CDM doesn’t require professional body membership, but it does require competence. Being part of a recognised body can be one of the clearest ways to demonstrate it.