Construction is one of the most hazardous industries in the UK, with workers exposed to risks that change daily as sites evolve. A construction risk assessment is the foundation for keeping people safe and projects legally compliant. Without a clear process for spotting hazards and controlling them, the likelihood of accidents, costly delays, and legal breaches increases substantially.
In this guide, we discuss the laws that make construction risk assessments mandatory, and who holds responsibility at different stages of a project.
What is a construction risk assessment?
A construction risk assessment, sometimes referred to as a building site risk assessment, is the structured process of identifying hazards on building sites, evaluating the risks they pose, and deciding on control measures to prevent harm.
Hazards in construction include working at height, moving vehicles, excavations, electrical systems, and exposure to dust or hazardous substances.
The purpose of a risk assessment for construction work is to:
- Safeguard workers, contractors, visitors, and the public from injury or ill health.
- Ensure that projects remain compliant with UK health and safety law.
Unlike relatively stable environments such as offices, construction sites are dynamic and high-risk, with conditions changing as projects progress, new contractors arrive, or plant and machinery are introduced. Because of this, risk assessments must be site-specific, reviewed regularly, and updated whenever circumstances change.
Are construction risk assessments a legal requirement?
Risk assessments are a legal requirement in construction. The primary duty comes from the Management of Health and Safety at Work Regulations 1999 (MHSWR), which apply across all workplaces.
Under Regulation 3(1), every employer must make a “suitable and sufficient assessment” of the risks to employees and anyone else who may be affected by their work.
Regulation 3(2) extends this duty to the self-employed, who must assess risks to themselves and others. These provisions form the foundation of all workplace risk assessments, including those carried out on construction sites.
In addition, the Construction (Design and Management) Regulations 2015 (CDM) place specific duties on clients, designers, and contractors to ensure risks are considered and controlled throughout a project. We discuss responsibilities later in the article.
Alongside these, a range of specific health and safety regulations require risk assessments for hazards common in construction. Here we discuss some of the most important, though this list is not exhaustive.
Work at Height Regulations 2005
The Work at Height Regulations 2005 require employers, the self-employed, and anyone who controls the work of others (such as building owners or facilities managers) to assess and manage the risks of working at height.
Regulation 6 requires employers to identify the measures needed to prevent falls, taking account of a “suitable and sufficient” risk assessment carried out under Regulation 3 of the Management of Health and Safety at Work Regulations 1999. In construction, this includes tasks such as scaffolding, roof work, use of ladders, or working on elevated platforms.
The assessment must determine whether work at height can be avoided, and where it cannot, identify measures to prevent falls or reduce the distance and consequences of a fall. Control measures may include using edge protection, safety nets, or personal fall protection systems.
Control of Asbestos Regulations 2012
Before any work that might disturb asbestos-containing materials, Control of Asbestos Regulations 2012 Regulation 6 requires employers to conduct a risk assessment. This must evaluate the type and condition of asbestos, the likelihood of fibre release, and the measures required to protect workers and others.
This duty is particularly relevant in refurbishment and demolition projects, where asbestos-containing materials (ACMs) are still frequently present in older buildings constructed before the year 2000.
Control of Substances Hazardous to Health Regulations 2002 (COSHH)
COSHH Regulation 6(1) requires employers to carry out a “suitable and sufficient assessment” of the risks posed by hazardous substances. On construction sites, this applies to materials such as silica dust released during cutting, cement that can cause burns or dermatitis, and solvents, paints, or welding fumes.
A COSHH assessment must show how exposure will be prevented or reduced through measures such as extraction, safe storage, or PPE. If risks remain, employers may also be required to provide health surveillance (for example, health monitoring for welders exposed to fumes).
To support employers with these duties, Praxis42 offers a specialist COSHH risk assessment service. Our experienced consultants identify hazardous substances, analyse safety data, assess exposure risks, and recommend proportionate control measures.
Control of Lead at Work Regulations 2002
The Control of Lead at Work Regulations 2002 require employers to assess the risk of exposure to lead where work may disturb lead or lead-containing materials.
Regulation 5 obliges employers to carry out a “suitable and sufficient assessment” to determine the nature and extent of the risk and the steps needed to ensure adequate control. On construction sites, this can arise during refurbishment or demolition of older buildings where lead-based paints, roofing materials, or pipework may be present.
The assessment must identify potential exposure routes and specify control measures. Where exposure is significant, medical surveillance of workers is required.
Manual Handling Operations Regulations 1992
Manual Handling Operations Regulations 1992 Regulation 4(1)(b) requires employers to make a “suitable and sufficient assessment” of manual handling operations that pose a risk of injury.
In construction, this duty covers tasks such as lifting concrete blocks, manoeuvring steel beams, or carrying bulky windows and doors.
Assessments must consider the load, the physical demands of the task, the environment, and the capabilities of the workers, and then set out measures to reduce risk, such as using mechanical aids or team lifting.
To help organisations meet these requirements, Praxis42 provides manual handling risk assessments carried out by experienced consultants. Our assessments are tailored to your operations, identify where risks are highest, and set out practical measures to protect workers and ensure compliance.
Noise at Work Regulations 2005
Under Noise at Work Regulations 2005 Regulation 5(1), employers must assess workers’ exposure to noise when it is likely to reach or exceed the lower exposure action value of 80 dB(A).
Construction activities such as piling, drilling, and use of heavy plant often generate noise above these levels.
A noise risk assessment must identify tasks where exposure is high and specify control measures, which may include engineering solutions, task rotation, or provision of hearing protection.
Control of Vibration at Work Regulations 2005
Control of Vibration at Work Regulations 2005 Regulation 5(1) requires employers to carry out a “suitable and sufficient assessment” where workers are exposed to vibration that could pose a risk to health. This includes hand–arm vibration from equipment such as breakers, drills, and compactors, and whole-body vibration from vehicles and plant like dumpers or rollers.
The assessment must measure or estimate workers’ daily exposure to vibration, compare the results with the Exposure Action Values (EAV) and Exposure Limit Values (ELV) set out in the Regulations, and determine control measures to reduce the risk of harm.
Confined Spaces Regulations 1997
The Confined Spaces Regulations 1997 place duties on employers to protect workers who enter confined spaces such as service ducts, sewers, tanks, or excavations.
These Regulations require duty holders to avoid entry into a confined space where it is reasonably practicable to do the work another way.
Where entry is unavoidable, Regulation 4 requires the work to be properly planned and carried out to a safe system of work. That safe system should be informed by a “suitable and sufficient” risk assessment under Regulation 3 of the Management of Health and Safety at Work Regulations 1999.
The confined spaces risk assessment must establish whether the work can be avoided. Where entry into a confined space is unavoidable, it must identify the hazards present and specify control measures.
Electricity at Work Regulations 1989
The Electricity at Work Regulations 1989 require all electrical systems to be constructed and maintained to prevent danger.
Although the Regulations do not use the phrase “risk assessment” explicitly, compliance depends on assessing electrical risks to ensure systems are safe and suitable systems of work are in place. In construction, this applies to activities such as setting up temporary site supplies, using portable tools, and working near overhead or buried cables.
A risk assessment must identify potential sources of electrical danger and determine appropriate control measures, such as isolation procedures, inspection and testing regimes, and ensuring only competent persons carry out electrical work.
Personal Protective Equipment at Work Regulations 1992 (amended 2022)
The Personal Protective Equipment at Work Regulations place a duty on employers and relevant self-employed persons to provide PPE where other measures do not adequately control the risk.
Although the Regulations do not use the phrase “risk assessment”, compliance depends on carrying out a suitable and sufficient risk assessment under Regulation 3 of the Management of Health and Safety at Work Regulations 1999 to determine when PPE is required.
In construction, PPE commonly includes hard hats, safety boots, high-visibility clothing, gloves, respiratory protection, and fall-arrest harnesses.
Who is responsible for carrying out a construction risk assessment?
The primary legal duty to carry out a construction risk assessment sits with the employer or duty holder under the Management of Health and Safety at Work Regulations 1999 (MHSWR), Regulation 3.
In construction, this duty is reinforced by the Construction (Design and Management) Regulations 2015 (CDM 2015), which set out responsibilities across different roles. This layered approach ensures that risks are identified and managed at every stage of a project, from planning through to day-to-day site management.
Clients – setting the framework for risk management
Under CDM 2015, Regulation 4, clients must ensure that suitable arrangements for managing health and safety are in place before construction begins, which includes appointing competent principal designers and principal contractors with the necessary skills, knowledge, and organisational capability.
Clients are also responsible for providing adequate time and resources so that work can be carried out safely.
Importantly, they must ensure that risk assessments and related measures are not treated as a formality but are practical and proportionate to the project’s scale and complexity.
Designers – eliminating and reducing risks at the planning stage
Under Regulation 9, designers have a duty to consider health and safety risks during the design stage of a project. Their responsibility is to eliminate, reduce, or control foreseeable risks through their design decisions, so far as is reasonably practicable.
This means that before work starts on site, designers must assess the potential risks arising from their designs and take steps to remove or minimise them. For example, choosing lighter materials can reduce manual handling risks.
Where risks cannot be eliminated entirely, designers must provide information to the client, principal designer, and principal contractor about the residual risks. This ensures that those risks are properly addressed in the construction phase risk assessments and managed safely on site.
Principal contractors – managing the whole site
Under Regulation 13, the principal contractor is responsible for coordinating health and safety across the site during the construction phase – the period when building or demolition work is actively carried out and site risks are at their highest.
As part of this duty, the principal contractor must prepare site-wide risk assessments that cover common hazards, including:
- Traffic management. Construction traffic such as delivery vehicles, dumpers, and excavators poses a serious risk if not properly controlled.
- Site access. Entry and exit points must be planned and monitored to prevent unauthorised access and ensure only trained and inducted personnel enter the site.
- Welfare facilities. Adequate welfare is a legal requirement, and the principal contractor must assess whether facilities such as toilets, washing areas, rest rooms, and drinking water are suitable.
- Emergency arrangements. Foreseeable emergencies, including fire, medical incidents, structural collapse, or flooding, must be planned for.
Principal contractors must coordinate and monitor subcontractors to check that their task-specific risk assessments are suitable and consistent with the safety strategy.
Communication is critical in meeting these responsibilities. Principal contractors must deliver comprehensive site inductions, hold regular safety briefings, and ensure supervision and monitoring are in place so that control measures remain effective as work progresses.
Contractors and subcontractors – task-specific risk assessments
Under Regulation 15, contractors and subcontractors are directly responsible for assessing and controlling the risks associated with the work they undertake. This means preparing task-specific risk assessments that address the hazards unique to their activities. For instance, a scaffolding company must assess the risks of erecting and dismantling scaffold towers.
They also have a duty to ensure their workforce is trained, competent, and supervised, and to coordinate with the principal contractor so that their activities do not create risks for other trades working on site.
Site managers and supervisors – implementing and monitoring controls
Site managers and supervisors are responsible for briefing workers on the risk assessments and safe systems of work before tasks begin, and for monitoring site conditions to check that control measures remain effective as projects progress. They must be prepared to stop unsafe practices where risk assessments are not followed and act as a link between workers and senior management.
By gathering feedback from the workforce and raising issues promptly, site managers and supervisors help ensure continuous improvement in risk management on site.
Specialist RAMS review for construction work
A thorough and clear construction risk assessment is vital for protecting people and keeping projects compliant. To support this, we offer a specialist Risk Assessment and Method Statement (RAMS) review service. Our experienced health and safety consultants carefully examine your documentation to ensure it is clear, practical, and aligned with legal requirements.
By choosing an independent review, you gain reassurance that your RAMS are compliant and effective for managing risks on site. This helps to build confidence among your workforce, demonstrate due diligence to clients, and reduce the likelihood of costly incidents or delays.
Learn more about our RAMS review service and discover how we can help strengthen your approach to construction risk management. Contact our friendly team today on 0203 011 4242 / info@praxis42.com
Adam Clarke
Managing Director (Consulting)
