CPD: Temporary works

Temporary works are not purely something that a contractor must address. Permanent and temporary works designers must communicate to ensure that structures and buildings can be constructed safely.

This is not a new message. Nearly 50 years ago, the Bragg Report on falsework, commissioned by the government in 1973 and published in 1976, was saying just that. Here’s an extract:

“It is obviously essential that good communications are established as quickly as possible between the designers of the permanent works and those designing the temporary works. This will ensure that time is not wasted in devising a method of construction that is subsequently found unacceptable.”

Bragg’s observations could be summed up in the ‘3Ps’ – people, process and product. 

Although the contractor, through the contract, is responsible for the construction itself, the role of the permanent works designer is vital – as is the role of the contractor’s temporary works coordinator and the principal designer (PD), who should be playing a central role.

In simple terms, temporary works can be said to be those parts of a construction project that are needed to enable the permanent works to be built. 

BS 5975: 2019, Code of practice for temporary works procedures and the permissible stress design of falsework (2019), is the nationally accepted standard for the procedural control to be applied to all aspects of temporary works. It represents ‘contemporary good practice’. 

The code of practice does not contain a concise definition of temporary works, but states that it can be described as providing an ‘engineered solution’ that is used to support or protect either an existing structure or the permanent works during construction (Clause 5.1.1.1). 

BS 5975: 2019 gives recommendations and guidance on the procedural controls to be applied to all aspects of temporary works in the construction industry. It provides three fundamental principles for controlling temporary works (Clause 5.1.1.10): 

BS 5975: 2019 also gives a very useful summary of the control measures that should be used to ensure safety for all temporary works (Clause 5.1.2), summarised in the following paragraphs:

Every organisation that has an involvement with temporary works should appoint a senior person to prepare, maintain and implement the organisation’s procedure for the control of temporary works – known as the designated individual. The PC’s designated individual should appoint a temporary works coordinator (the PC’s temporary works coordinator), responsible for all temporary works on the project. 

There are additional recommendations, depending on the size of project. For example, on large or complex sites, there may be more than one PC’s temporary works coordinator. In this case, each PC’s temporary works coordinator should be responsible for a distinct, well-defined area of work. Where there is more than one PC’s temporary works coordinator and/or temporary works coordinator, the limits of responsibility, interfaces and boundaries should be recorded in writing. 

Any subcontractor to the PC or another contractor – for instance, one working directly for the client – who is contracted to manage their own temporary works and who is working within a PC’s temporary works coordinator’s area of responsibility, should appoint a temporary works coordinator. Note that this temporary works coordinator, who should be appointed by the contracted organisation’s designated individual, should report to the relevant PC’s temporary works coordinator for the area in which they operate. 

The PC’s temporary works coordinator and the temporary works coordinator should have the same level of management training. Their technical and practical knowledge should be commensurate with the complexity of the work. Where required, the PC and contractor may appoint temporary works supervisors who report to their temporary works coordinator. 

Except for very low-risk temporary works, a design brief should be prepared for the temporary works by the site team and issued by the temporary works coordinator to the temporary works designer. Where the category of design check has not been specified, the temporary works designer, in consultation with the relevant temporary works coordinator, should confirm the category and prepare the necessary design output.

The temporary works design checker should carry out the design check of the temporary works, and in certain categories without reference to the temporary works designer’s calculations, before issuing a certificate confirming the design is satisfactory.

Once the site team has constructed the temporary works in accordance with the certified design, the temporary works coordinator or temporary works supervisor, as appropriate, should issue a permit to proceed, confirming the temporary works have been erected in accordance with the certified design and any agreed revisions. 

BS 5975: 2019 (Clause 6.1.3) recommends that the implementation risk for each item of temporary works should be classified. The implementation risk comes from combining the execution risks, associated with workmanship, materials and experience, with the consequence of failure risks – where the temporary works are and what could be affected if they fail.

The classifications should be taken from BS 5975: 2019, Table 1, which sets out the class of implementation risk – very low, low, medium or high – along with the permits required and other control measures needed. Note that mitigation of risks associated with design should be addressed through the category of design check (Clause 13.7) which should not be confused with the implementation risk.

HSE guidance on the CDM 2015 regulations states: “When preparing or modifying designs, a designer must take account of the general principles of prevention, and the pre-construction information provided to them, with the aim, as far as reasonably practicable, of eliminating foreseeable risks. 

“Where this is not possible, they must take reasonably practicable steps to reduce the risks or control them through the design process and provide information about the remaining risks to other dutyholders.”

Despite this, there has been – and continues to be – much discussion over many years on this aspect of legislation. Bookcases groan under the weight of published tomes of guidance, yet there is still no consensus on design risk management.

A recent survey on design risk management within the Temporary Works Forum (TWf), 25 years after CDM was first introduced, identified findings that are deeply concerning. Shortcomings and barriers include a lack of constructability knowledge among many permanent works designers, fee-driven constraints, perceived liabilities, lack of 
leadership and a conflict between contract and statute over the manner of project management. 

The role of the principal designer should be central to successful design risk management, but it seems that many PDs are failing in their responsibilities, according to TWf members. 

As part of a 2021 survey commissioned by the HSE to broaden understanding of the CDM 2015 principal designer role, answers from TWf members reported that they had not noted any improvement in the management of temporary works since the introduction of the PD role – which is seen as a failed role like the planning supervisor and CDM coordinator before them.

TWf members also reported that few PDs are involved actively with temporary works designers. Many are “detached” and “one step removed”.  However, there are some indications that on larger jobs with “intelligent clients” the role is discharged more effectively, demonstrating the influence of the client.

BS 5975: 2019 reminds dutyholders that permanent works designers should address the buildability of the permanent works and identify and make provision for any temporary works and temporary conditions required by their design and their assumed method of construction. 

This should include a proposed method and sequence of construction which should have no adverse effects on the permanent works (Clause 8.3.1).

Design risk management is a means by which designers can demonstrate that their designs can be built, used, maintained and eventually demolished without negatively affecting the safety, health and wellbeing of those involved in the construction process or those who may be impacted by the structure. There is useful guidance on design risk management (see box, p23) which applies equally to temporary works designers and permanent works designers. l

David Thomas is director and secretary of the Temporary Works Forum (TWf).

A selection of useful best practice guides and templates for managing temporary works

Now take the CPD module below. Note that you must register or sign in on the Project Safety Journal website first.