✓ Updated February 2026

Working at Height Questions — CSCS Practice

25 focused questions on the UK's leading cause of construction fatalities

Working at Height: The UK's Biggest Construction Killer

Falls from height are consistently the leading cause of fatal accidents in the UK construction industry, responsible for approximately 40-50% of all construction deaths each year. The Work at Height Regulations 2005 were introduced to address this devastating toll and establish a clear framework for managing the risks of working at height.

Understanding these regulations is essential for every construction worker, not just those who regularly work at height. Any work where a person could fall a distance liable to cause personal injury is classified as work at height. This includes work on ladders, scaffolds, roofs, mobile elevated work platforms (MEWPs), and even work near unprotected edges or openings at any level.

The Work at Height Regulations 2005

The Work at Height Regulations 2005 (as amended) apply to all work at height where there is a risk of a fall liable to cause personal injury. They place duties on employers, the self-employed, and anyone who controls the work of others. The Regulations establish a clear hierarchy for managing work at height:

  1. Avoid work at height where it is reasonably practicable to do so
  2. Prevent falls using an existing safe place of work or appropriate work equipment (guardrails, working platforms)
  3. Minimise the distance and consequences of a fall using collective measures (safety nets, airbags) or personal measures (safety harnesses, fall arrest systems)

Ladder Safety on Construction Sites

Ladders are one of the most commonly used and most commonly misused items of work equipment on construction sites. While they are sometimes appropriate for short-duration, light-duty tasks, they should never be the default choice for work at height. Key ladder safety points include:

Scaffold Safety Requirements

Scaffolding is one of the most critical safety systems on a construction site. Scaffolds must be erected, altered and dismantled by trained and competent scaffolders, typically holding a CISRS (Construction Industry Scaffolders Record Scheme) qualification. Key requirements include:

Edge Protection and Fall Prevention

Edge protection must be provided at any point where a person could fall a distance liable to cause personal injury. This includes open floor edges, stairwell openings, roof edges, lift shafts, and any other unprotected voids. The Regulations specify that collective protection (such as guardrails) is preferred over personal protection (such as harnesses) because it protects everyone in the area without relying on individual compliance.

Harnesses and Fall Arrest Systems

When collective fall prevention is not practicable, personal fall protection systems may be used. These include work restraint systems (which prevent the wearer from reaching a fall edge) and fall arrest systems (which catch a person who has already begun to fall). Key points include:

⚠ Key Fact

A fall from as little as 2 metres can be fatal. There is no minimum height threshold in the Work at Height Regulations — if someone could fall and be injured, the Regulations apply.

Disclaimer: This is a free practice resource. For official test booking, visit citb.co.uk.

Frequently Asked Questions

What is the legal definition of working at height?

Under the Work at Height Regulations 2005, 'work at height' means work in any place, including a place below ground level, from which a person could fall and injure themselves. This includes work on ladders, scaffolding, roofs, and even ground level near excavations or openings.

When must a risk assessment be carried out for working at height?

A risk assessment must be carried out before any work at height. It should identify hazards, assess who could be harmed, evaluate the risks, and determine control measures. The hierarchy of control is: avoid working at height where possible, use collective protection (scaffolding, guardrails), then personal protection (harnesses) as a last resort.

What are the main causes of falls from height on construction sites?

The main causes include: unsecured ladders, missing or inadequate edge protection, fragile roofing materials (e.g. asbestos, corrugated sheeting), inadequate scaffolding, overreaching, and failure to use personal protective equipment such as harnesses and lanyards.

How far can a scaffold board overhang its support?

A scaffold board should not overhang its support by more than four times its thickness. For a standard 38mm board, the maximum overhang is approximately 152mm (four times 38mm). Excessive overhang creates a trip hazard and risks the board tipping.

What is a PASMA qualification?

PASMA (Prefabricated Access Suppliers' and Manufacturers' Association) qualification is the industry-recognised training certificate for the safe use of mobile access towers. It covers erection, dismantling, and use of aluminium mobile scaffold towers. A PASMA certificate is often required before workers can erect or use mobile towers on construction sites.