On construction sites across the UK, temporary works—from excavation support systems and formwork to scaffolding and propping—are essential to enable permanent structures to be built safely. Yet failures in these temporary systems remain a leading cause of structural incidents, delays and fatalities. In 2024/25, construction recorded 35 worker fatalities at a rate of 1.92 per 100,000 workers, roughly 4.8 times the all-industry average. Temporary works contribute disproportionately to that figure, not because of design errors alone, but due to breakdowns in coordination, communication and control.

The Temporary Works Coordinator (TWC) sits at the heart of that control system. Appointed by the contractor, the TWC is a competent person responsible for coordinating the planning, design, checking, implementation, use and dismantling of temporary works on a construction project. Under BS 5975 and CDM 2015, the TWC ensures that designs are produced, independently checked and correctly implemented—and holds explicit authority to stop unsafe work.

What Does a Temporary Works Coordinator Actually Do?

The TWC is not the designer, nor the site supervisor. The role is procedural, ensuring that all temporary works are properly planned, designed, checked, implemented and removed in accordance with BS 5975. The TWC acts as the central point of control, linking designers, site teams, subcontractors and management to ensure that temporary works are not installed, altered or removed without proper approval.

This distinction matters because temporary works often change during the construction process, requiring continuous coordination rather than a one-off design decision. The TWC ensures that the system adapts safely to those changes.

Core Duties of the Temporary Works Coordinator

The TWC's responsibilities span the entire lifecycle of temporary works on site. Key duties include:

  • Temporary Works Register: Establishing and maintaining the temporary works control system on site, ensuring all temporary works are recorded in a register that tracks design, approval, implementation and removal stages.
  • Design and Design Checks: Ensuring that all temporary works designs are carried out by competent designers and that appropriate independent design checks are completed before implementation. The TWC must verify that designs are suitable for the intended purpose and that any design assumptions are clearly communicated to the site team.
  • Permit to Load / Proceed: Managing the permit-to-load or permit-to-proceed system, ensuring that temporary works are not used until they have been inspected and approved. This is a critical control point that prevents unsafe or incomplete systems from being put into service.
  • Coordination and Communication: Acting as the link between designers, site teams, subcontractors and management to ensure that changes, modifications or unexpected conditions are flagged, assessed and approved before work proceeds.

Where the TWC Role Sits in UK Law and Standards

BS 5975 is not itself compulsory, but the duty to plan, manage and monitor temporary works is statutory. Under CDM 2015 Regulation 13 and Sections 2 and 3 of the Health and Safety at Work etc. Act 1974, contractors must ensure that temporary works are properly controlled. BS 5975 is the industry standard that defines how that duty is discharged. In practice, the Health and Safety Executive, insurers and courts will use BS 5975 as the yardstick for compliance.

The TWC appointment is therefore not a paperwork preference—it is an operational necessity. A prosecution does not ask whether you used BS 5975; it asks how you controlled the temporary works, and BS 5975 is the framework against which that control will be judged.

How the TWC Fits in the Temporary Works Hierarchy

The TWC does not work in isolation. BS 5975 establishes a hierarchy of defined roles, including the Temporary Works Supervisor (TWS), who oversees implementation on site, and the Temporary Works Designer, who prepares the design. The TWC coordinates these roles, ensuring that design intent translates into safe site execution.

The TWC also liaises with the Principal Contractor's Designated Individual, who provides formal authority to stop work on unsafe or non-compliant temporary works. This authority is written into the appointment and backed by the employing organisation.

Common Failures in TWC Management

Evidence from site incidents shows that failures in temporary works are frequently linked to coordination breakdowns rather than design errors. Common failure patterns include:

  • Temporary works installed without design checks or approval.
  • Changes made on site without informing the TWC or designer.
  • Permit systems bypassed or not enforced.
  • TWC appointed in name only, without authority or involvement in day-to-day control.
  • Designs not communicated to site teams, or design assumptions ignored during implementation.

In constrained, fast-paced projects—common in urban environments—these breakdowns are more likely unless the TWC role is resourced, empowered and embedded in site workflows.

What This Means on Site

For contractors, the TWC appointment must be more than a name on an organogram. The role requires competence, authority and active involvement throughout the project lifecycle. The TWC must be appointed early, involved in planning, and given the resources and backing to enforce compliance.

For site teams, the TWC is the go-to point for all temporary works queries, changes and approvals. No temporary works should be installed, altered or removed without TWC sign-off. The permit-to-load system is non-negotiable—it is the final control that ensures temporary works are safe to use.

For clients and principal contractors, ensuring that the TWC role is properly resourced and empowered is a direct CDM 2015 duty. The TWC is not an administrative add-on; it is the control function that ensures temporary works do not become a source of structural failure, injury or delay.

Competence, Training and Appointment

The TWC must be competent, meaning they have the knowledge, experience and training to coordinate temporary works safely. BS 5975 does not mandate specific qualifications, but industry practice typically requires formal training in temporary works coordination, supported by relevant site experience.

The appointment must be formal, written and clearly define the TWC's authority, limits and responsibilities. The TWC must have access to senior management and the authority to stop work where temporary works do not comply with approved designs or procedures.

In practice, the TWC role is often filled by a senior site engineer or project manager with temporary works training. On larger or more complex projects, a dedicated TWC may be appointed to manage the workload and maintain control across multiple work fronts.

Related guidance on site safety systems can be found in our explainers on telematik systems, hubarbeitsbühnen safety protocols, and ROPS-Kabine standards. For operators managing equipment on site, understanding wartungsintervalle and betriebsstunden tracking is equally critical to safe, compliant operation.