Risk Assessment Construction: Method and Singapore Rules

Every construction activity carries hazards: work at height, lifting, excavation, hot work, electricity, moving plant. A risk assessment construction teams carry out properly identifies those hazards before work starts, evaluates how serious they are, and puts controls in place so the work can be done safely. In Singapore, it is also a legal requirement under the Workplace Safety and Health framework.

This article explains what the law requires, how a construction risk assessment is carried out step by step, how risks are rated and controlled, and how designers and engineers contribute. It is a practical overview, not a substitute for the official codes of practice and guidelines.

The legal basis in Singapore

The Workplace Safety and Health (Risk Management) Regulations, made under the Workplace Safety and Health Act, require employers, self-employed persons and principals, including contractors and sub-contractors, to conduct risk assessments of the safety and health risks that persons at work may be exposed to. They must take reasonably practicable measures to eliminate or minimise those risks.

Several obligations follow from the regulations and the Ministry of Manpower’s guidance:

The risk assessment must be reviewed, and revised where necessary, at least once every three years, and earlier when there is an accident or a significant change in work processes, equipment or materials.
A record of the assessment, including the control measures and safe work procedures, must be kept, and the guidance states it should be retained for at least three years.
Persons at work who may be affected must be informed of the risks, the control measures and the safe work procedures, and informed again when the assessment is revised.

The Ministry of Manpower enforces these requirements, and the Workplace Safety and Health Council publishes a code of practice on risk management and supporting guidelines that set out an accepted method.

The risk assessment construction method, step by step

The accepted method follows a sequence that most construction firms will recognise:

1. Preparation

Form a team that includes people who know the work: supervisors, workers who will do the job, and specialists where needed, such as a lifting supervisor or a Professional Engineer for temporary works. Gather information: drawings, method statements, equipment manuals, site conditions and past incident records.

2. Hazard identification

Break the work into activities and identify what could cause harm in each. For construction, typical hazards include falls from height, falling objects, collapse of excavations or formwork, struck-by plant and vehicles, lifting failures, electrocution, fire from hot work, manual handling, noise, dust and heat stress.

3. Risk evaluation

For each hazard, estimate the severity of the likely harm and the likelihood of it occurring, taking existing controls into account. Combine them into a risk level, commonly using a matrix.

4. Risk control

Decide on control measures to bring the risk to an acceptable level, following the hierarchy of controls, and identify who will implement them and by when.

5. Record keeping, implementation and review

Record the assessment, communicate it to workers, implement the controls and monitor that they are working. Review the assessment periodically and whenever conditions change.

Rating risk: the severity and likelihood matrix

Most construction risk assessments use a matrix that multiplies or combines severity and likelihood. A simple version uses three levels for each:

Severity: minor (first-aid injury), moderate (injury requiring medical treatment or time off), major (fatality, serious injury or permanent disability).
Likelihood: remote (not likely to occur), occasional (possible or known to occur), frequent (common or repeated occurrence).

The combined rating is then grouped as low, medium or high risk, with guidance on what each level means: a low risk may be acceptable with existing controls; a medium risk needs further controls and close supervision; a high risk means work should not proceed until the risk is reduced.

The matrix is a tool for consistency and communication, not a precise calculation. Two teams can rate the same hazard differently; what matters is that the discussion leads to effective controls. Where a hazard has potential for multiple fatalities, such as a crane collapse or excavation failure, it deserves engineering analysis, not just a matrix score.

Applying the hierarchy of controls on site

Controls should be chosen starting from the most effective:

Elimination. Remove the hazard, for example by prefabricating an element at ground level instead of assembling it at height.
Substitution. Replace with something less hazardous, such as a less toxic product or a smaller, lighter component.
Engineering controls. Physically separate people from the hazard: guardrails, edge protection, shoring to excavations, machine guarding, dust extraction.
Administrative controls. Safe work procedures, permits to work, exclusion zones, training, supervision and rotation to limit exposure.
Personal protective equipment. The last line of defence, as discussed in our article on construction PPE.

In practice, several controls are combined. A deep excavation, for example, relies on an engineered earth retaining system, monitoring instruments, barricades, safe access, supervision and PPE together. Our guide to deep excavation shoring shows how engineering controls carry most of the load in that case.

Common gaps in construction risk assessments

Experience across many sites shows recurring weaknesses:

Generic templates. Copying an assessment from a previous project without reflecting this site’s conditions, sequence and equipment.
Missing the people who do the work. Assessments written in the office without input from the workers and supervisors on site miss practical hazards.
Not updated as the site changes. Construction sites change daily. New phases, new equipment, weather and changes in sequence all need review.
Controls not implemented. A well-written assessment that is filed and forgotten provides no protection. Controls must be checked on site.
Poor communication. Workers, especially those with limited English, need the key risks and controls explained clearly, for example in toolbox meetings and in their own languages.
Overreliance on PPE. Defaulting to PPE where engineering controls are practicable.

For a broader view of site safety systems, see our article on construction safety.

The role of designers and engineers

Many of the most serious construction hazards are fixed at design stage. Singapore’s Workplace Safety and Health (Design for Safety) Regulations require developers and designers on qualifying projects to identify and address foreseeable risks in the design, through a design for safety review process, and to pass information on residual risks to the contractor.

From a structural engineering perspective, risk assessment construction work relies on is strongly linked to temporary works: formwork and falsework, shoring, scaffolds, crane foundations, propping during demolition or alterations, and lifting arrangements. These need to be designed, checked and inspected by competent engineers, with clear limits communicated to the site. A risk assessment that says “ensure formwork is stable” without an engineered design behind it does not control the risk.

For alteration and demolition work in existing buildings, unknowns such as hidden defects, undocumented structure or deteriorated concrete add risk. A structural engineering consultancy can investigate the existing structure and design temporary support before work begins.

Frequently asked questions

Is risk assessment mandatory for construction work in Singapore?

Yes. The Workplace Safety and Health (Risk Management) Regulations require employers, self-employed persons and principals, including contractors, to conduct risk assessments for the work they carry out and to implement reasonably practicable control measures.

How often must a risk assessment be reviewed?

The regulations require a review at least once every three years, and earlier whenever there is an accident, a significant change in work processes, or new information about the hazards. On construction sites, assessments are typically reviewed much more often because conditions change quickly.

How long must risk assessment records be kept?

Ministry of Manpower guidance states that records of risk assessments, including control measures and safe work procedures, should be kept for at least three years. Many firms keep them for the full duration of a project and beyond.

What is the difference between a risk assessment and a method statement?

A risk assessment identifies hazards, evaluates risks and sets controls. A method statement describes step by step how a task will be done, including the sequence, equipment, people and the controls from the risk assessment. The two are complementary and are often prepared together.

Who should be involved in a construction risk assessment?

The people who plan, supervise and carry out the work, supported by specialists where needed, such as safety professionals, lifting supervisors or Professional Engineers for temporary works. Involving workers improves the quality of hazard identification and acceptance of the controls.

Planning alterations, demolition or temporary works and need the engineering risks assessed? Talk to our consultancy or get in touch.