Scaffolding design principles under scrutiny after HSE prosecutes two firms for fatal-risk skylight fall

Two construction companies have been fined a combined £79,300 after a 26-year-old scaffolder fell more than six metres through a warehouse roof skylight in Keighley, West Yorkshire, suffering a broken arm, a broken leg and head lacerations ^[1]. The case, heard at Leeds Magistrates' Court on 4 June 2026, was accompanied by the release of CCTV footage showing the moment of impact, which the Health and Safety Executive (HSE) described as 'harrowing' ^[2]. In the same fortnight, the National Access and Scaffolding Confederation (NASC) published a new TG4 User Guide and site poster on scaffold anchor ties — a reminder that sound scaffolding design principles extend well beyond the structure itself to every element of how rooftop work is planned, managed and evidenced ^[3].

What happened and what HSE found

James Cranswick was installing temporary scaffolding edge protection for Clover Access Systems Limited at Acre Mills, Keighley, on 14 January 2025, when the incident took place ^[4]. He was carrying materials across the roof when he stepped onto a skylight that was almost indistinguishable from the surrounding roof surface, and fell more than six metres to the concrete floor below ^[5].

An HSE investigation found that both Clover Access Systems Limited and principal contractor STM360 Limited had failed to plan, manage and monitor the roof work adequately ^[6]. The regulator said no measures were in place to prevent workers falling from the roof edge or through fragile elements, and that the skylights were 'almost invisible' to anyone on the roof ^[7]. Clover Access Systems pleaded guilty to breaching Regulation 15 of the Construction (Design and Management) Regulations 2015 and was fined £26,000 with £2,866 costs; Scaffmag reported the company is now in liquidation ^[8]. STM360 Limited pleaded guilty to breaching Regulation 13 of the same regulations and was fined £53,300 with costs of £3,167 ^[9].

HSE inspector Shauna Halstead stated that the fall was wholly avoidable and that the risks associated with working on or around fragile surfaces are well known ^[10]. She added that the HSE would not hesitate to take enforcement action where roof work is not properly managed ^[11].

Two readings of the verdict

The prosecution can be read as a straightforward enforcement story: a worker was not protected, the regulator acted, and both the scaffolding subcontractor and the principal contractor paid the price. HSE's published guidance sets out a clear hierarchy — avoid fragile-roof access where possible, then provide physical protection, then use fall-arrest systems as a last resort ^[12]. On that reading, both firms simply failed to follow established rules that are decades old.

A second reading is less comfortable for the wider industry. The incident happened while the team was installing edge protection — ostensibly a safety measure — which means the hazard arose during the scaffolding operation itself, not in spite of it. Commentators in trade press have pointed to the CDM 2015 duty to plan, manage and monitor as a shared obligation sitting with both the principal contractor and specialist subcontractor simultaneously, regardless of who holds the contract ^[13]. That shared-liability structure is often under-negotiated in scaffold subcontracts, and this case illustrates how the courts apply it. Understanding scaffolding design principles in their broadest sense, including the pre-construction information duty and the requirement to identify fragile surfaces before work begins, is therefore as much a commercial management question as a technical one. ScaffSkills' guide to CITB funding changes 2026 sets out the wider training context for managers looking to build that competence without relying solely on grant support (https://scaffskills.com/guides/citb-funding-changes-scaffolding).

Why this is a contractual question, not only a safety one

CDM 2015 Regulation 15 — breached by Clover Access Systems in this case — places an explicit duty on the principal contractor to plan, manage, monitor and coordinate construction work, including work carried out by specialist subcontractors ^[14]. Regulation 13 — breached by STM360 — requires every contractor to plan, manage and monitor their own workers' activities ^[15]. When both regulations are engaged in the same incident, the contractual allocation of pre-construction information, method statement approval and site supervision becomes decisive evidence in any subsequent proceeding.

The commercial implication is direct. Scaffold subcontracts that are silent on who supplies pre-construction information about fragile surfaces, who approves the method statement for traversing the roof, and who bears liability for inadequate planning leave both parties exposed. Any tender or contract for roof-edge protection work should include explicit provisions for fragile-surface surveys, agreed safe routes of travel, and documented supervisor checks before work above fragile elements begins. Managers who want a structured approach to these obligations will find that NASC's Guide to Good Practice for Scaffolding with Tube and Fittings — TG20 — and its sister guidance TG30 for system scaffolding address the design and compliance documentation requirements that underpin those contractual provisions ^[16].

The concurrent NASC TG4 launch adds a second documentation thread. NASC published a new A6 pocket User Guide and A2 site poster on 22 June 2026 to accompany TG4:25, its technical guidance on scaffold anchorage systems ^[17]. The TG4 User Guide is aimed at scaffolders who install and test drilled and cast-in anchors, covering the checks and precautions needed to protect anchor integrity ^[18]. NASC specifies that at least 5% of anchors must be selected at random for proof testing on each project, with a minimum of three anchors tested in each separate area ^[19]. For commercial managers, anchor test records are a contractual deliverable on most principal-contractor frameworks; the new pocket guide makes the on-site discipline easier to enforce and verify.

What a scaffolding manager should know: three checks

The following procedural checks are drawn from the HSE prosecution record, CDM 2015 and NASC TG4:25 guidance. They are not a substitute for legal advice or a full method statement, but they represent the minimum due-diligence questions any manager responsible for roof-edge or facade-access work should be able to answer before work begins.

The cost of a proper pre-construction information review is measured in hours; the cost of proceeding without one is measured in years.