Coe or Ovett? Oasis or Blur? Ketchup or brown sauce? All questions that lead to heated debate and for which there is no clear answer. And since 6 April, there's a new question to add to the list - who should you appoint as your principal designer?

The Construction (Design and Management) Regulations 2015 (CDM Regulations 2015) have created the new role of a principal designer. This effectively replaces the CDM co-ordinator (which itself was a replacement for the position of Planning Supervisor under the original 1994 Regulations).

The previous transition from planning supervisor to CDM co-ordinator created few problems, as both roles fell squarely in the 'health and safety' camp, so incumbent planning supervisors could switch effortlessly into the new co-ordinator role.

The same cannot be said of the change to Principal Designers, as the role combines elements of health and safety advisor and a technical designer.

The Health and Safety Executive's (HSE) Guidance Note on the Regulations sets out the thinking behind the new role and the change in approach. The aim is to move away from the bureaucratic, 'box ticking' approach that was suggested by some to be the hallmark of the planning supervisor and CDM co-ordinator roles and towards a system where health and safety issues are considered at the earliest opportunity and are embedded in the design process. The HSE is firmly of the opinion that design decisions made early in a project have a significant impact on the health and safety outcomes.

So, who is this polymath that can fulfil the role of Principal Designer?

Regulation 5 requires a client to appoint as principal designer, a designer with control over the pre-construction phase of a project; designer is defined as any person who prepares or modifies a design or arranges for, or instructs, any person under their control to do so.

All fairly straightforward so far; but then you get the definition of design (which has been widely drafted). Not only does it cover documentation typically produced by architects and engineers (i.e. "technical designers") - drawings, design details, specifications - but also material (such as bills of quantities and calculations) normally produced by project managers, employer's agents and/or quantity surveyors (i.e. those traditionally viewed as "non-designers"). And given that the liberal interpretation of design feeds through to the definition of designer, the role of principal designer can, theoretically, be fulfilled by any number of the consultants - technical designer or arguably non-designer - typically employed on a construction project.

Many existing specialist health and safety consultants who are currently operating as CDM co-ordinators have used the cover afforded by the legislative drafting to promote themselves as potential principal designers. But is the mere fact that you fall within the ambit of generously constructed classification sufficient qualification for the role?

According to Regulation 8, the client must satisfy itself that the appointee has the necessary skills, knowledge, experience and organisational capability to fulfil the role of principal designer. Given the HSE's stated aim of embedding good health and safety practice into the design process at the earliest opportunity, the principal designer must be able to control health and safety by influencing the pre-construction technical design phase.

Surely this dictates that whoever is appointed to the role has to have a fair degree of involvement, insight and influence and militates against a non-technical "designer" fulfilling the role. Further, by creating the position of principal designer, the HSE is moving away from the perception that characterised the role of CDM co-ordinator, namely that it was set apart from the core design team.

So, if we know who it should not be, is there an answer to who it should be? No - or, more precisely, not yet.

One approach that is beginning to take hold among clients is to appoint, as principal designer, one of the consultants from the design team (i.e. the architect or engineer) - at least for the pre-construction phase. While, theoretically, almost any consultant on a typical project can fulfil the role, the approach of appointing a key 'technical' designer would appear to align most closely with the HSE's philosophy.

There is a certain logic in appointing the lead, given their role in co-ordinating and integrating the overall design of a project, as the person tasked with managing, monitoring and co-ordinating health and safety aspects of the project. But how does the theory translate into reality. Are architects and engineers ready to be the gatekeepers of health and safety?

No doubt the larger design practices, especially the multi-disciplinary ones, who previously provided CDM co-ordinator services, will be capable of fulfilling the role (as they will have the requisite skill sets within their organisation). However, potentially, a smaller design firm that has stuck to its core offering (of architectural and engineering services) rather than specialising in 'pure' health and safety expertise, may not.

And therein lies the fundamental dilemma arising out of the new Regulations and the principal designer role they have created. Not every project team contains the multi-faceted, 'Renaissance' man, woman or organisation that is ideally suited to discharge the role. So, faced with the real prospect of being singled out to fulfil the role, what can our specialist architects and engineers do?

First, they can say 'no' (and risk alienating their client). Alternatively, they can acquire the expertise - either permanently (by adding staff with the appropriate experience and qualifications) or by sub-contracting out aspects of the role to specialist health and safety consultants. This 'sub-contracting out' approach was not uncommon under the old Regulations, where many project managers took on the role of CDM co-ordinator and appointed a sub-consultant to perform the duties.

However, this approach may fall foul of the designers' professional indemnity insurance (at least in the short term until the market gets to grips with the principal designer's function). Equally, the enhanced 'designer' element contained within the principal designer's obligations may take the role beyond the current remit of many specialist health and safety consultants' professional indemnity insurance cover and preclude them from fulfilling the role.

And where do contractors fit in to all this? The newly issued amendments to the various standard forms of contract envisage that a contractor can be appointed as principal designer for the construction phase of a project. There is logic to this, especially on design and build projects, where the contractor has single point design responsibility. However, there will still be the need to appoint a principal designer for the period prior to the contractor's appointment, so the problem does not go away.

We are still in the very early stages of the new regulations, so maybe it is unrealistic to expect there to be a definitive answer. However, the concern (from a client's perspective) is that, while the risks (and potential penalties) fall on the clients' side, the solution will ultimately have to come from the consulting community (in co-operation with their insurers and professional bodies). And that solution has to come sooner rather than later.