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What are temporary works and who is responsible on site?

Last checked 24-10-2026. A plain guide, not legal advice: check the official guidance below for your job.

Temporary works are the structures that support or protect the job while the permanent work is built, such as props, falsework, formwork, excavation support and scaffolds. CDM 2015 requires them to be designed, installed and maintained for the loads they will carry, and HSE says they need planning and managing as carefully as the permanent works.

What counts as temporary works

HSE describes temporary works as the parts of a project needed to build the permanent works, usually removed afterwards. Its list of temporary works that give structural support includes:

  • shoring and support for excavations
  • propping for walls and floors, such as props and needles holding up masonry over a new opening
  • falsework and formwork for concrete poured above ground
  • scaffolds for access
  • haul roads and working platforms for plant, including cranes
  • permanent works used for temporary purposes during construction

HSE also counts site fencing and hoarding, welfare and office units, and earthworks such as stockpiles that will be removed later. It says temporary works need the same care as permanent works.

What CDM 2015 requires

  • Regulation 19. All practicable steps must be taken to stop a structure collapsing if the work makes it unstable or temporarily weak. Any temporary support or structure must be designed, installed and maintained to withstand foreseeable loads, and used only for what it was designed for.
  • Designers. CDM counts formwork, falsework, scaffolds and other temporary support or access as structures. On that wording, whoever prepares a temporary works design is a designer, with the regulation 9 duties to design out foreseeable risks where reasonably practicable, or reduce and control them.
  • Excavations (regulations 22 to 24). Where an excavation has supports or battering, a competent person must inspect it at the start of each shift and after events that could affect its stability, before anyone works in it. Regulations 23 and 24 cover cofferdams, caissons and inspection reports.
  • Regulations 13 and 15. The principal contractor must plan, manage and monitor the construction phase, and each contractor must do the same for their own work. Temporary works fall inside that.

HSE says no specific legal requirements dictate how temporary works are managed. The legal test it gives is that the party in control must allocate and carry out the work so it does not create an unacceptable risk of harm to workers or the public.

The temporary works coordinator

HSE says an effective way to manage temporary works is to appoint a temporary works coordinator (TWC), who makes sure suitable designs are prepared, checked and correctly built on site. BS 5975 sets out one way of managing temporary works that HSE says works well on medium and large projects, and it uses the TWC job title. There is no legal requirement to use the title or the standard's process, but HSE calls BS 5975 the industry consensus on good practice. On a simple job you may choose not to appoint a TWC, but you must still make sure the temporary works are properly managed.

HSE says a TWC should be formally appointed, with enough authority to stop unsatisfactory work. On a simpler job the main contractor may take the role and take advice from an engineer. An engineer who designs the temporary works is not automatically the coordinator, because coordinating also covers planning, installation, use and maintenance.

Design, check, permit to load and permit to strike

In outline, using HSE's wording where it has one:

  • Design. Apart from the simplest cases, a design with calculations is needed. Standard solutions exist, such as a system scaffold, or a trench box for a 2 m excavation in firm, dry ground, but someone must still check the ground and that the supplier data fits the site. Screw props need the loads worked out, including side loads, by someone who knows how. Not every structural engineer has the training for temporary works design.
  • Check. For more complex works, HSE says the design should be checked by an independent party.
  • Permit to load. A sign-off before the structure is loaded, for example before a pour onto falsework. HSE lists authorisation to load among the steps the person organising the works must coordinate, after checking completion.
  • Permit to strike. A sign-off before the structure is removed, sometimes called a permit to dismantle. HSE lists removal as part of the same coordination.

The names permit to load and permit to strike are site practice, not terms in the regulations. Check what the principal contractor's procedure expects. Put the arrangements in the construction phase plan, which regulation 12 says must set out the health and safety arrangements and site rules. HSE also says scaffolds, excavations, cofferdams and caissons must be inspected by a competent person regularly.

Sources

Tools that help

Inspections, permits and weekly paperwork PROWeekly checks on the day they're due: scaffold, safety, PUWER and temporary works, filled in from last time, plus the equipment register and permits.Construction phase plan PROThe CDM construction phase plan every job needs, domestic too: team, dates, site rules, welfare, fire, the significant risks, RAMS and the F10 check.RAMS PRORisk assessments and method statements from 104 ready-made construction tasks, made site-specific, with your logo, signed and kept with the job.

More guides

How often does a scaffold have to be inspected?How often a scaffold must be inspected under the Work at Height Regulations 2005, who can do it, what the report must say and how long to keep it.When does an excavation have to be inspected under CDM 2015?When a competent person must inspect an excavation under CDM 2015 regulation 22, when the report is due, and the main risks and controls for builders.How do you avoid hitting buried services when digging?How to avoid hitting buried services, following HSE's HSG47: get plans, scan with a cable locator, mark up, hand dig, and what to do if you strike one.

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