Managing health and safety in construction – The general principles of prevention

1 Introduction

The introduction to HSE’s Managing health and safety in construction (L153, Para. 5)¹  states that the ‘general principles of prevention’ set out the principles dutyholders - namely designers, principal designers, principal contractors and contractors - should use in their approach to identifying the measures they should take to control the risks to health and safety in a particular project. 

Although they are legal duties, the principles also provide a framework for ethical and thoughtful design to help you:

• Prevent accidents
• Support a strong safety culture
• Ensure designs are not just technically sound but socially responsible

2 Summary

The general principles of prevention are set out in full in Appendix 1 to L153, but in summary they are to: 

• Avoid risks where possible
• Evaluate those risks that cannot be avoided 
• Put in place proportionate measures that control them at source

NOTE: Assumptions may be documented in a ‘design risk register’ and should be incorporated in the ‘pre-construction information’ (PCI).
 

3 General principles of prevention: Appendix 1

Following the principles are a requirement of the Management Regulations² and apply to all industries, including construction. They provide a framework to identify and implement measures to control risks on a construction project.

The general principles of prevention are to:  
(a)     avoid risks
(b)     evaluate the risks which cannot be avoided
(c)     combat the risks at source
(d)     adapt the work to the individual, especially regarding the design of workplaces, the choice of work equipment and the choice of working and production methods, with a view, in particular, to alleviating monotonous work, work at a predetermined work rate and to reducing their effect on health
(e)     adapt to technical progress
(f)     replace the dangerous by the non-dangerous or the less dangerous
(g)     develop a coherent overall prevention policy which covers technology, organisation of work, working conditions, social relationships and the influence of factors relating to the working environment
(h)     give collective protective measures priority over individual protective measures, and
(i)     give appropriate instructions to employees
 

4 General principles of prevention: designers

The duties on designers are set out in CDM2015 Regulation 9³:
(2)     When preparing or modifying a design the designer must take into account the general principles of prevention and any pre-construction information to eliminate⁴, so far as is reasonably practicable, foreseeable risks to the health or safety of any person—
         (a)     carrying out or liable to be affected by construction work;
         (b)     maintaining or cleaning a structure; or
         (c)     using a structure designed as a workplace. 
(3)     If it is not possible to eliminate these risks, the designer must, so far as is reasonably practicable—
         (a)     take steps to reduce or, if that is not possible, control the risks through the subsequent design process; 
         (b)    provide information about those risks to the principal designer; and
         (c)     ensure appropriate information is included in the health and safety file.
(4)     A designer must take all reasonable steps to provide, with the design, sufficient information about the design, construction or maintenance of the structure, to adequately assist the client, other designers and contractors to comply with their duties under these Regulations.
 

5 ERIC

This process is sometimes simplified in industry guidance as E-R-I-C (Eliminate – Reduce – Inform – Control)⁵.
 

6 What these principles mean for a structural engineer

Examples of the principles might be:
(a)     Avoid risks

• Design out hazards from the start

Example: Do not include fragile roof panels if workers will need to walk on them.

(b)     Evaluate unavoidable risks

• If a risk cannot be eliminated, assess how serious it is and who might be affected

Example: If working at height is necessary, consider fall protection systems early in the design, e.g. permanent edge protection, safe walkways, fixed access systems.

(c)     Combat risks at source

• Tackle risks where they arise, and not downstream

Example: Specify non-slip finishes on walkways rather than relying on signage or training alone.

(d)     Adapt work to the individual

• Consider human factors in designs, e.g. comfort, ergonomics, and mental load

Example: Design access platforms that reduce awkward postures or repetitive strain.

(e)    Adapt to technical progress

• Stay current with technologies that improve safety or sustainability
• Learn from incidents or discoveries that may require a rethink of design or construction philosophies or strategies

Example: Use modern materials that are safer to install or maintain, like modular components.

(f)     Replace dangerous with safer alternatives

• Choose safer design options or materials wherever possible 

Example: Where appropriate, consider prefabricated or modular construction methods to reduce site exposure.

(g)     Develop a coherent prevention policy

• Think holistically: designs should support safe construction, use, maintenance and demolition

Example: Coordinate with architects, contractors, and clients to ensure safety is embedded across the lifecycle.

(h)     Prioritise collective protection over individual protection

• Design systems that protect everyone, not just rely on personal protective equipment (PPE)

Example: Include edge protection in the design rather than assuming workers will wear harnesses.

(i)     Give appropriate instructions

• Provide clear, usable information about risks and how to manage them

Example: Include notes in drawings or specifications that highlight significant residual risks and safe methods of work.
 

7 Discussion

The general principles of prevention are not just as a list, but a ‘hierarchy of intent’. 

Some observations:

1. They are not equal. They are in an order of priority.

Although not explicitly numbered as a hierarchy, (a) through (h) broadly move from elimination, to control, to mitigation, to communication. In practice:

• (a) to (c) are about designing out risk
• (d) to (g) are about systemic and organisational control
• (h) to (i) are last lines of defence

2. “Combat at source” (c)

This is often under-applied. In construction, including temporary works, risk is frequently managed downstream, e.g. method statements, PPE, rather than (for example):

• Eliminating work at height through design, or
• Removing manual handling through prefabrication

This is where CDM dutyholders often fall short, particularly designers.

3. Adapt the work to the individual, etc. (d)

This is more significant than it first appears. “Adapt the work to the individual (etc.)” goes well beyond ergonomics. It implies:

• Consideration of competence and capability
• Fatigue, workload, and production pressure
• Human reliability

In modern terms, this is essentially a ‘human factors’ requirement, though the wording may be considered dated.

4. Develop a coherent overall prevention policy (g)

This is the bridge to safety culture and systems thinking. It is arguably the most strategic principle:

• It requires integration across technology, organisation, and people
• It anticipates what is now described (more accessibly) as a whole-system approach to risk management

This is where safety maturity models, e.g. RM3⁶, fit directly.

5. Collective vs individual protection (h)

This remains a persistent industry weakness. Despite being explicit, many sectors still default to:

• PPE before engineering controls
• procedural controls before physical safeguards

This is often driven by cost, programme pressure, or fragmented responsibilities.

6.“Instructions to employees” (i)

Instructions are necessary but generally less reliable than elimination or engineered controls when used in isolation:

• They rely entirely on human behaviour
• They are prone to drift, error, and non-compliance

Yet in practice, many risk assessments still end here. 
 

8 Practical reframing

The general principles of prevention can be presented under three clearer ‘themes’:

• Eliminate and reduce risk at source
  • Avoid risks
  • Combat risks at source
  • Replace dangerous with less dangerous
  • Adapt to technical progress

• Design and manage work systems effectively
  • Evaluate unavoidable risks
  • Adapt work to the individual
  • Develop coherent prevention policy

• Control residual risk
  • Prioritise collective protection
  • Provide appropriate instruction

9 A final thought …

When designing it is useful to test decisions against the hierarchy by asking: “Why was this risk not avoided?”, “What prevented elimination at source?” and/or “Why was PPE selected over collective protection?” This line of questioning tends to expose whether the principles are being applied genuinely or simply being cited.

EXAMPLE

Constrained urban basement construction

Preamble

The following example illustrates how the general principles of prevention may be applied by structural engineers on a complex basement project in a constrained city-centre environment.

The scenario is deliberately typical of many medium- to high-risk urban developments: a multi-storey basement, limited access, adjacent structures, significant temporary works, and intensive interaction between excavation, logistics, craneage, and structural sequencing. Such projects often present substantial construction risks long before the permanent structure is complete.

The examples focus on matters that structural engineers can realistically influence through concept and detailed design decisions, particularly:

• Structural form and grid arrangement
• Excavation and stability strategy
• Integration of temporary and permanent works
• Buildability and sequencing
• Access, logistics, and human factors

The intention is not to prescribe a single solution, but to demonstrate how early design decisions can either eliminate risk at source or, if poorly considered, transfer risk downstream to contractors through increasingly complex temporary works, procedures, and reliance on human behaviour.

In practice, the greatest opportunity to apply the general principles of prevention occurs during concept design, when fundamental choices remain open. By the time construction begins, many opportunities for elimination and substitution have already been lost.

Scenario

Three-storey basement, city centre, constrained site, limited access, tower cranes, steel/concrete frame, retaining walls, e.g. piles, props, walings.

The examples focus on what the designer can realistically influence, particularly at concept and detailed design stages.

General principles of prevention: Examples

(a)     Avoid risks

Eliminate hazards through fundamental design decisions

• Reduce or eliminate basement depth where feasible, e.g. two levels instead of three, to avoid deep excavation risks altogether
• Consider top-down construction to avoid prolonged open excavation and reduce temporary works exposure
• Optimise the structural grid to minimise the need for internal temporary propping, reducing congestion and high-risk interactions below ground
• Design basement layout to avoid confined, inaccessible voids, e.g. rationalise plant spaces and access routes

(b)     Evaluate risks which cannot be avoided

Structured design risk management for the constrained environment

• Assess risks associated with:
  • Deep excavation adjacent to existing buildings, e.g. ground movement, settlement.
  • Temporary stability of retaining walls during staged excavation
  • Restricted logistics and lifting operations due to limited access
• Evaluate buildability of piling, walings, and propping sequences, including worst-case load cases
• Consider interaction with adjacent structures, e.g. need for monitoring, sequencing constraints
• Identify high-risk construction stages, e.g. installation/removal of props at depth

(c)     Combat risks at source

Design out root causes of risk rather than relying on site controls

• Design retaining walls and floor slabs to enable top-down construction, providing early restraint and reducing excavation exposure
• Detail permanent slabs to act as props, eliminating or reducing temporary propping systems
• Specify integral lifting points in heavy steel members and precast elements to avoid improvised lifting arrangements
• Design connections to allow bolted assembly from safe positions, avoiding site welding in constrained basement conditions
• Ensure inherent stability at each excavation stage, reducing reliance on procedural controls

(d)     Adapt the work to the individual

Account for human factors in a constrained basement environment

• Provide sufficient working space around props, walings, and structural elements to allow safe installation, inspection, and removal
• Design safe access routes, e.g. stairs and not ladders where practicable, into and within the basement during all stages
• Limit manual handling by:
  • Designing components to suit crane lifts
  • Avoiding excessively heavy or awkward elements in constrained areas
• Consider lighting, ventilation, and visibility in deep basement design. This influences safety during construction and maintenance

(e)    Adapt to technical progress

Use modern methods and tools to reduce risk

• Use BIM and 4D sequencing to model excavation, propping, and frame erection, identifying clashes and unsafe sequences early
• Adopt prefabricated steelwork and reinforcement systems to reduce on-site work in constrained conditions
• Consider instrumentation and monitoring systems, e.g. for ground movement and structural behaviour, integrated into the design
• Use digital rehearsal of lifting operations to validate crane reach and sequencing in a constrained urban site

(f)     Replace the dangerous with the non-dangerous or less dangerous

Substitute higher-risk methods and materials

• Replace extensive in-situ work at depth with precast or modular elements where practicable
• Specify bolted steel connections instead of welded connections in constrained basement areas
• Use secant or diaphragm walls, preferably as free cantilevers, that provide both temporary and permanent function, reducing additional temporary works
• Select construction methods that minimise time spent in deep excavation, e.g. early slab installation

(g)     Develop a coherent overall prevention policy

Integrate safety across design, construction, and lifecycle

• Coordinate structural design with:
  • Geotechnical design, e.g. retaining walls, ground conditions
  • Construction methodology, e.g. top-down vs bottom-up
  • Logistics planning, e.g. craneage, access constraints
• Ensure the design supports a safe construction sequence, not just a compliant end state
• Consider whole-life issues:
  • Safe maintenance access within the basement
  • Inspection of retaining structures and drainage systems
• Align with the client and contractor on buildability strategy early, e.g. temporary works philosophy embedded in permanent design

(h)     Give collective protective measures priority over individual measures

Design in physical, shared protections

• Incorporate permanent edge protection or upstands at slab edges as early as possible in construction
• Design permanent stair cores to be constructed early, providing safe access instead of temporary ladders
• Provide integrated barriers or covers to openings, e.g. lift shafts, service penetrations
• Design layouts that reduce interaction between plant, lifting operations, and personnel in confined spaces

(i)     Give appropriate instructions to employees

Communicate significant residual risks clearly

• Highlight key temporary stability requirements on drawings, e.g. sequencing of excavation and propping
• Clearly identify significant residual risks such as:
  • Working adjacent to retained ground and existing structures
  • High-load temporary props and their removal sequence
• Provide specific, concise notes, e.g. “Do not remove prop X until slab Y has achieved design strength.”
• Ensure meaningful input to the Health and Safety File, particularly for:
  • Basement inspection and maintenance
  • Long-term performance of retaining structures

Closing observation

In this scenario, the most significant risk reduction opportunities lie in:

• Basement construction methodology, viz. top-down vs bottom-up
• Integration of permanent works with temporary stability functions
• Early coordination of logistics in a constrained urban site

If these are not addressed at concept stage, the project will default to managing risk through temporary works, procedures, and PPE, i.e. the least effective end of the hierarchy.

Key point for practice

For a structural engineer, the effectiveness of these principles is determined largely at:

• Concept design, e.g. RIBA Stage 2, where elimination and substitution are most achievable
• Detailed design, e.g. RIBA Stage 4, where buildability and safe sequencing are locked in

Once on site, most opportunities to apply (a) to (f) have already been lost, leaving only (h) and (i), which are the least effective.

References
¹ Managing health and safety in construction, Construction (Design and Management) Regulations 2015, Guidance on Regulations, L153, https://www.hse.gov.uk/pubns/books/l153.htm

² The Management of Health and Safety at Work Regulations 1999, https://www.legislation.gov.uk/uksi/1999/3242/contents 

³ A more detailed explanation is provided in L153, Paras 81 to 90

⁴ NOTE: Highlighting added

⁵ A valuable reference is IStructE’s An introduction to prevention through design
NOTE: ERIC has its roots in ERICPD: Eliminate – Reduce – Isolate – Control – Protect - Discipline

⁶ Risk Management Maturity Model (RM3), https://www.orr.gov.uk/guidance-compliance/rail/health-safety/strategy/rm3