Temporary Works Register

Definition

A Temporary Works Register is the master list of every structure on a construction site that is not part of the permanent works but is nevertheless load-bearing, life-safety-critical, or both. It is the single artefact a Temporary Works Coordinator (TWC) uses to prove that every temporary structure has been designed, checked, erected, inspected and eventually dismantled in a controlled sequence. The concept is codified in BS 5975 in the UK and echoed in the requirements of most competent Tier-1 contractors worldwide.

What Belongs on the Register

• Scaffolding — birdcage, façade, mobile towers.
• Formwork and falsework for slabs, beams, walls and columns.
• Excavation shoring, sheet piling, trench boxes.
• Crane bases, outrigger pads, and lifting frames.
• Propping and back-propping schemes for concrete curing loads.
• Temporary bracing for steel erection.
• Edge protection, working platforms, loading bays.
• Site hoardings and gantries where structural stability is engineered.
• Temporary drainage, dewatering wells, or de-watering settlement tanks under load.

Why It Matters

Temporary works kill people. The UK HSE has consistently reported that failure of temporary works — most notably falsework collapse — is one of the highest-consequence categories in construction. The register is the mechanism that ensures nothing on that list is designed on the back of an envelope, erected without check, or dismantled before the permanent structure can carry its own load. It also gives the project a defensible record if a load event, weather event, or incident later triggers an investigation.

Real-World Example

On a 220 kV substation civil works package, the register listed 47 temporary structures across the 14-month programme. Item 23 was the back-propping scheme for the transformer plinths — three tiers of props holding successive pours while the concrete gained strength. The propping designer had specified a minimum 14-day cure before de-propping the lowest level. During a schedule-recovery push, a supervisor asked to strike props at day 9 to release access for the next trade. The TWC refused, produced the load calculation from the register, and escalated to the project manager. The scheme was revised with additional shoring — three days added, several tonnes of props hired — and the pours cured without incident. The alternative was a plausible chain that ended in a collapsed slab and a fatal accident.

Practical Lessons Learned

• The TWC is not the designer. The role is to coordinate — to make sure the designer, the checker, the site team and the removal sequence all line up on the same drawing.
• Every item needs a category (0, 1, 2, 3 in BS 5975 terms). Categories drive the level of independent checking required — do not let items drift downwards to avoid check.
• Erection and dismantling are separate hold points. Sign the erection off before load; sign the dismantling off before removal. Never let the crew "just get on with it."
• The register is a scheduled artefact. Every item has a planned erection date and a planned removal date; both align with the Gantt schedule.
• Photograph inspections. A tagged photo at handover of the scaffold is the only credible evidence that the erected structure matched the design.

Common Mistakes

• Treating scaffolding as "just scaffolding" and leaving it off the register.
• Designer and checker being the same person — an audit finding waiting to happen for anything above Category 1.
• De-propping decisions made verbally on site because the concrete "looks fine."
• No removal sequence — temporary works stay in place long after they should because nobody owns their exit.
• Register held by the TWC alone, with no visibility to the planning or QA teams.
• Modifying erected temporary works (extra loads, additional lifts, cut braces) without a written variation to the design.
• Assuming a proprietary system supplier's generic drawings satisfy the site-specific design requirement.

Expert Tips

• Colour-code by category on the register itself — a Category 3 item hidden in a long list of Category 0 items is the one that gets missed.
• Interlock with the permit-to-work system. No permit for load, cast, dismantle or modify without a matching entry on the temporary works register.
• Weekly TWC walk. The register is only as honest as the last physical inspection.
• Keep the design pack on site. A subcontractor cannot verify compliance with a drawing that lives in head office.
• Close out formally. Every entry needs a "removed and inspected" line, not just a blank date.

Key Takeaways

• Temporary works are life-safety-critical; the register is the mechanism that keeps them under control.
• Every item has a category, a designer, an independent checker, an erection sign-off and a removal sign-off.
• The register is scheduled — planned in, planned out — never a static file.
• Modifications require written design variations; verbal changes belong on other projects.
• The TWC coordinates; the designer designs; the site erects; the checker verifies. Blurring roles is where failures start.

Related Concepts

Interlocks with Permit to Work, Method Statement, Constructability Review, and Quality Gate. TWC checklists and category matrices at PMMilestone.org.