These guidelines help you to consider health and safety when designing plant, structures or substances.

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Health and Safety by Design: an introduction (PDF 3.2 MB)

Key points

1.0 Introduction

1.1 Who is this guidance for?

These good practice guidelines are for persons conducting a business or undertaking (PCBUs) with a role in designing structures, plant or substances. These people may include:

• designers
• PCBUs who are employing or engaging designers of structures, plant or substances to be used, or could reasonably be expected to be used, at work
• people who make decisions about the design or redesign of structures, plant or substances
• external experts who contribute to design projects.

The guidelines are for people who want to learn about designing with health and safety in mind.

1.2 What does it cover?

Designers are ‘upstream PCBUs’. An upstream PCBU’s duties are important because they can influence the health and safety of products and structures before they’re used at work. The guidelines explain these designer duties, and describe how designers can manage health and safety risks (called ‘Health and Safety by Design’). These guidelines could be used for projects of varying sizes.

The guidelines:

• begin with general concepts that cover the Health and Safety at Work Act 2015 (HSWA)(external link)
• look at the key principles of Health and Safety by Design
• describe Health and Safety by Design – what’s good practice when considering the design of structures, plant and substances.

These guidelines are based on guidance produced by Safe Work Australia.¹

Key elements of good practice have been adapted for a New Zealand audience.

These guidelines cover the basic principles of Health and Safety by Design. The Health and Safety by Design process can apply to plant, substances, structures, materials, technology, facilities, equipment, hardware, software  and the way workers interact with these. These guidelines don’t cover every aspect listed above, but act as a starting point for PCBUs.

Key points

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^{1  Safe Work Australia Handbook Principles of Good Work Design (2015), Safe Work Australia Code of Practice Safe Design of Structures (2012) ,Safe Work Australia Guide for Safe Design of Plant (2014).}

^{2 Adapted from the UK HSE Construction (Design and Management) Regulations 2015.}

2.0 What is Health and Safety by Design?

2.1 Health and Safety by Design

‘Health and Safety by Design’ is the process of managing health and safety risks throughout the lifecycle of structures, plant, substance or other products. Designers are in a strong position to make work healthy and safe from the start of the design process. Health and Safety by Design is not a separate concept from good design – they are the same thing.

Figure 1 shows the decrease in ability to influence safety that a PCBU has over the lifecycle of a product.

2.2 Why is Health and Safety by Design important?

It is important to think about health and safety risks at the design stage. Here’s why:

Research illustrates its benefits

International research³ shows the following:

• Good design can result in significant reductions in work-related ill-health and injuries.
• Good design reduces damage to property and the environment, and the related costs.
• Good design enhances the health, wellbeing and productivity of  workers.
• The most effective risk control measure – eliminating hazards – is often cheaper and more practicable to achieve at the design or planning stage than managing risks later in the lifecycle.
• The design of plant or structures contributes to a significant proportion of work-related injuries, and solutions already exist for many of those design problems.
• It is more efficient and effective to manage risk in the design phase than to retrofit health and safety solutions.
• Design based on Health and Safety by Design principles can reduce the need for retrofitting, personal protective equipment, health monitoring, exposure monitoring, and maintenance.

Smart design of products can help provide a high level of protection for end users

Workers have the right to the highest level of protection, so far as is reasonably practicable. Managing risks in the design stage of a product is an effective way of providing the best protection. It is more effective than, for example, retrofitting a product later in its lifecycle.

Smart design of products makes good business sense

Eliminating health and safety risks before they happen makes good business sense for PCBUs. People who work in safe, healthy conditions are less likely to take time off work and will be more engaged and positive in their job.

This may mean that productivity is increased in the long run.

Health and Safety by Design is also important for developing and maintaining a good reputation to win future work. It gives businesses the opportunity to become leaders in their industry and become the most desirable places to work.

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^{3 Safe Work Australia Work-related fatalities associated with unsafe design of machinery, plant and powered tools 2006-2011 (2014) Safe Work Australia Handbook Principles of Good Work Design (2015)}

^{Safe Work Australia Code of Practice Safe Design of Structures (2012) Safe Work Australia Guide for Safe Design of Plant (2014)}

^{Approved American National Standard ANSI/ASSE Z590.3 Prevention through design – Guidelines for addressing occupational hazards and risks in design and redesign processes (2011)}

^{Health and Safety Executive Research Report RR218 Peer Review of analysis of specialist group reports on causes of construction accidents (2004).}

3.0 Health and safety duties

What is HSWA?

The Health and Safety at Work Act 2015 (HSWA) is New Zealand’s work health and safety law. It sets out the principles, duties and rights in relation to work health and safety. There are different groups of people that hold health and safety duties under HSWA, called ‘duty holders’. They are:

• persons conducting a business or undertaking (PCBUs)
• officers
• workers
• other persons at workplaces.

A person may have more than one duty (eg a person can be a PCBU and a worker).

More than one person may have the same duty (eg different PCBUs may have the same duty towards the same worker).

Duties of all PCBUs

A PCBU must ensure, so far as is reasonably practicable, the health and safety of workers, and that other people are not put at risk by work carried out as part of the conduct of the PCBU. This is called the ‘primary duty of care’. Figure 2 below illustrates the people who may be affected by a PCBU’s work.

Engage workers about decisions on Health and Safety by Design

PCBUs must involve their workers and their representatives in work health and safety.

PCBUs have a general duty to engage with workers. In addition, they must engage under specified circumstances which include when identifying hazards and assessing risks to health and safety, and when making decisions about ways to manage health and safety risks.

They must also have practices that give their workers reasonable opportunities to participate effectively in improving work health and safety on an ongoing basis (these are known as worker participation practices). This includes processes for workers to report health and safety issues such as concerns that risks are not being adequately managed.

Having worker representatives is one way for workers to participate. Well-established ways to do this include having Health and Safety

Representatives (HSRs), Health and Safety Committees (HSCs) and unions. Other representatives can include community or church leaders.

More than one PCBU can have a duty around the same matter. This might happen in a contracting chain, or when different PCBUs work on the same site. This is known as having ‘overlapping duties’.

PCBUs must carry out their overlapping duties to the extent they have the ability to influence and control the matter. They must also, so far as is reasonably practicable, consult, cooperate, and coordinate activities with each other.

Although PCBUs can’t contract out of their health and safety duties, contractual agreements can be one way of setting out health and safety expectations for each PCBU. Responsibility to consult, cooperate and coordinate with the designer also applies to contractors and sub-contractors who win a tender.

Eliminating and minimising risk

Risks to health and safety arise from people being exposed to hazards (anything that can cause harm). Managing risks involves identifying hazards and then assessing risk to determine which work risks to deal with first, and how the risks should be dealt with.

PCBUs must eliminate health and safety risks arising from work so far as is reasonably practicable. If it’s not practicable to eliminate, they must minimise risks, so far as is reasonably practicable. This applies for matters that are within their ability to influence or control.

3.3 Additional duties for designer PCBUs

There are further duties for PCBUs who are designers, manufacturers, suppliers, importers and installers (so called upstream  PCBUs).  Upstream  duties apply to any PCBU that:

• designs, manufactures, imports, or supplies structures, substances or plant to be used in a workplace; or
• installs, builds or commissions plant or structures to be used, that could be or reasonably expected to be used, as or at a workplace.

An upstream PCBU’s duties are important because upstream duty-holders can influence the safety of products and structures before they’re used in work. This may help to eliminate risks. Table 1 below provides an overview of these duties for designer PCBUs.

Duties for designer PCBUs

Duty to, so far as is reasonably practicable, make sure that structures, plant and substances are without health and safety risk	Make sure, so far as is reasonably practicable, the plant, substance or structure designed is without health and safety risks to people who: use the plant, substance or structure at a workplace for its designed purpose handle the substance at a workplace store the plant or substance at a workplace construct the structure at a  workplace carry out reasonably foreseeable workplace activities (such as inspection, cleaning, maintenance or repair) in relation to: the manufacture, assembly or use of the plant, substance or structure for its designed or manufactured purpose the proper storage, handling, decommissioning, dismantling or disposal of the plant, substance or structure are at or near a workplace, and are exposed to the plant, substance or structure, or whose health and safety may be affected by a work activity listed above.
Duty to test	Carry out calculations, analyses, tests or examinations needed to make sure the structure, plant or substance designed is without health and safety risks so far as is reasonably practicable (or arrange the carrying out of such tests). Note: Where multiple designers are contributing to a project, they all hold responsibilities to carry out their testing duties for the individual parts that they are designing.
Duty to provide information	Provide adequate information to people who are provided with the design of the plant, structure or substance. This includes information about: the purpose for which the plant, substance or structure was   designed the results of any calculations, analyses, tests or examinations carried out to make sure the plant, substance or structure is without health and safety risks (in relation to a substance, this includes any hazardous properties of the substance identified by testing) any conditions necessary to make sure the plant, substance or structure is without health and safety risks when used for its designed purpose, or when being handled, stored, constructed, or other foreseeable activities such as inspection, cleaning, maintenance, or repair in relation to: the manufacture, assembly or use of the plant, substance or structure for its designed or manufactured purpose the proper storage, handling, decommissioning, dismantling or disposal of the plant, substance or structure. On request, make reasonable efforts to give the current relevant specified information on the purpose, results of calculations, analysis, testing and examination, conditions necessary to make sure it is without risk to a person who carries out or is to carry out work activities listed above with the plant, structure or substance.

Table 1: Duties of designer PCBUs (based on the requirements in Section 39 of HSWA)

3.4 Roles and responsibilities in Health and Safety by Design

Throughout the design process of a structure, plant or substance, different people contribute ideas, solutions and knowledge to help manage health and safety risks. PCBUs involved in the design process must consult, cooperate with, and coordinate activities with each other, so far as is reasonably practicable.

In general, the more influence and control a PCBU has over a health and safety matter, the more responsibility it is likely to have.

Figure 3 describes the roles of designers, the manufacturer of the design, the supplier of the manufactured product and the end-user. Adequate information or instructions for safe use should be made available between all the identified parties.

Cllient	Designer/design team	Manufacturer/Constuctor	Supplier	End-user
commissions the design could be the end user	designs the plant, structure, or substance	builds or assembles the plant, structure, or substance could be the supplier	sells the plant, structure or substance for use in the workplace could be the manufacturer	the PCBU that will use the product
Consults, cooperates and coordinates with the designer/design team, so far as is reasonably practicable.	Consults,  cooperates and coordinates with themanufacturer/constructor of their design, so far as is reasonably practicable. Provides information to the manufacturer/constructor about the purpose ofthe plant, structure or substance, the results of any calculations, testing etc to make sure that risks are minimised so far as is reasonably practicable, and any conditions necessary to make sure that risks are minimised so far as is reasonably practicable (when used for its designed purpose or when being inspected, cleaned maintained or repaired). On request, provides information as described above to those who will manufacture or supply the structure, plant or substance.	Consults,  cooperates and coordinates with the designer/design team, so far as is reasonably practicable.  Health and safety risks they identify are referred back to the designer/design team for review.  On request, provides information as described in Table 1 to those who sell or use the plant, structure or substance in the workplace.	On request, provides information as described in Table 1 to those who use the plant, structure or substance in the workplace. Should tell manufacturer/ constructor of any faults they become aware of that may create health and safety risks.	Should tell supplier of any faults that may create health and safety risks. Can ask the supplier or manufacturer/constructor (may be the same PCBU) for information on a structure, plant or substance.

Figure 3: Roles and responsibilities in Health and Safety by Design

4.0 Elements of Health and Safety by Design

4.1 Key principles of Health and Safety by Design

As shown in Figure 4, WorkSafe’s approach to Health and Safety by Design outlines five key principles. They are discussed in more detail below.

People 

A capable team

Combining great design and risk management can be achieved with a team of capable people. Consultation, coordination and cooperation are essential, particularly between the client and the designer. Teams need strong leadership, technical knowledge, and an understanding of the workplace that products will be used in including how they will be used. A team should be made up of capable people with a variety of different skills and knowledge, and should include workers who will use the structure, plant or substance.

People who have responsibility for designing work processes and systems have a key role in Health and Safety by Design. This includes a wide range of work health and safety professionals such as:

• generalist health and safety practitioners
• occupational  hygienists
• hazardous substances professionals
• safety, risk and reliability engineers
• occupational health physicians and nurses
• human factors professionals/ergonomists.

A team of capable people may hold these skills:

• knowledge of work health and safety legislation, good practice guidance and other regulatory requirements
• an understanding of the intended purpose of the design
• knowledge of risk management processes
• knowledge of technical design standards
• an appreciation of construction methods and their impact on the design
• the ability to source and apply relevant data on human dimensions, capacities and behaviours.

Risk management

A lifecycle approach 

Choosing inherently safer and healthier options should be the initial consideration when selecting which solution or technology to apply, even before entering the design process. When in the design process, Health and Safety by Design is most effective when applied at the earliest stage. Health and Safety by Design principles should be applied throughout the lifecycle of the the thing being designed – from the concept through to decommissioning and disposal.

The lifecycle encompasses design, planning, assembly, installation, construction, manufacture, commissioning, use, handling, cleaning, maintenance, inspection, repair, transport, storage, dismantling, demolition, or carrying out any reasonably foreseeable activity/work for a purpose for which it was designed.

Procurement

Health and Safety by Design principles should be embedded throughout the procurement  process.

For example:

• consult with end user representatives in pre-design or early design phases
• choose designers, contractors or consultants who are proven and able to deliver key Health and Safety by Design principles
• ensure that Health and Safety by Design expectations (evidence, standards, documents, communications etc) are included in procurement and contract processes
• choose materials and products based on Health and Safety by Design considerations
• bring suppliers into the consultation and design process to collectively engineer or design solutions.

Figure 5 shows the different lifecycle stages of a structure, plant or substance.

A risk management approach

Risks to health and safety arise from people being exposed to hazards (anything that can cause harm). This includes workers and others.

Designers must eliminate health and safety risks arising from work so far as is reasonably practicable. If it’s not practicable to eliminate, they must minimise risks, so far as is reasonably practicable.

Designers should take a systematic approach when identifying and managing work risks that are within their ability to influence or control. Figure 6 outlines an approach that can be taken.

Seek the views of your workers and their representatives when assessing work risks or making decisions about ways to manage risk. Your workers will have operational day-to-day knowledge that will be invaluable.

Wherever possible, design safety reviews should involve the people who will eventually construct, manufacture or maintain the structure, plant or substance.

If this is not possible, the client and designer should include people with knowledge and experience in the construction and maintenance processes in the design safety reviews. Their expertise will help with identifying health and safety issues which may have been overlooked in the design.

Designers can use the hierarchy of controls (Figure 7) to help them work out the most effective control measures, so far as is reasonably practicable. Table 2 describes the types of control measures.

  

When considering risk management, designers should think about:

• capability of workers who will use the product
• control measures that protect multiple people at once.
• Risks must be eliminated so far as is reasonably practicable. If a risk can’t be eliminated, it must be minimised so far as is reasonably practicable.
• Risk management is not just hazard spotting. Risk management involves identifying and then assessing which work risks to deal with. Risk has two components – the likelihood that it will occur and the consequences (degree of harm) if it happens. To manage risk, you can reduce how serious the harm is if it does occur and/or reduce the chances of it occurring, or ideally both.
• Check if there are widely used control measures (eg industry standards) for that risk. However, just because something is a common practice doesn’t mean that it’s the most reasonably practicable option. You should focus on the most effective control measures for the risks.
• The management of risk needs to be appropriate/proportionate for the scale of the risk. This means risks with potentially significant consequences (eg chronic ill-health, serious injury, and death) may require more effort and resources to determine the most effective way to manage the risk.
• You may need to use multiple control measures to adequately deal with a given risk.

Information formats

Design safety report

One method of communicating specific health and safety information relating to the design of a structure/plant is by providing a Design Safety Report.

The Design Safety Report should include information about:

• the purpose of the structure/plant as communicated by the client in the project brief
• the parties consulted in undertaking the design
• the hazards and risks identified during the design process, and control measures incorporated into the design, specifically in relation to:
• any hazardous materials specified in the design
• any unusual or atypical features requiring specific attention during construction and manufacture
• any features of the design which present specific risks
• the recommended control measures for any foreseeable activities (eg operation, maintenance, repair, dismantling, demolition, disposal) to be carried out during the life of the structure/plant when used for its intended purpose.

Records: Work health and safety file

The development of a work health and safety file (containing all relevant information for a structure/plant) will assist the designer to meet the duty to provide information to others. It could include copies of all relevant health and safety information the designer prepared and used in the design process, such as the Design Safety Report, risk register, product technical statements, safety data sheets, manuals and procedures for safe maintenance, dismantling or eventual demolition.

Frequent monitoring and review

Ongoing monitoring and review throughout design and the lifecycle improves outcomes and allows for variation as new information arises, such as unexpected risks. It will also confirm whether the Health and Safety by Design intent is being achieved. Change management processes will be necessary.

Here are some ways you can monitor and review your control measures:

• Monitor the effectiveness of all steps of the risk management process. This is important for continuous improvement. Monitor risks and the effectiveness of control measures. Make sure that control measures have not introduced any new risks, and that control measures are effectively managing the risks.
• On-going review ensures that the data obtained through monitoring is available for feedback into the system.
• Make sure that the safety recommendations and residual risks within the design are documented for users ‘downstream’ in the lifecycle.
• Take steps to make sure that essential modifications and maintenance are carried out and documented for future users.
• Designs or redesigns should be continually monitored and adjusted to adapt to changes in the workplace. Make sure that new information is used to improve design.
• As the design progresses and design decisions become more fine-tuned and detailed, there are still opportunities for managing risks. Wherever possible, design safety reviews should involve the people who will eventually construct the structure, plant or substance. If this is not possible, the client and designer should include people with the right knowledge and experience.

Their expertise will assist in identifying health and safety issues which may have been overlooked in the design. Peer review of design and risk assessment from industry/professional groups is encouraged. This approach can encourage collaboration and professional  development.

Change management⁴

A robust change management process based on good training and awareness should be implemented and maintained throughout the entire asset life cycle.

A formal change approval process should be in place, and this should specifically require any health and safety implications to be considered. For Health and Safety by Design, considerations may include questions such as:

• Does the change impact on the design intent?
• Does the change impact on the design risk register?
• Does the change affect an item identified as a safety or health risk mitigation?
• Does the change challenge the safe design envelope?
• Does the change introduce new risks?
• Does the change result in excessive schedule pressure that may compromise the quality of deliverables?
• Does the change impact on the methodology?
• Does the change impact on the risk register?
• Does the change require changes to organisational  structures?
• Does the change require changes to work practices, such as moving to an outsourced model for maintenance, engineering or project management?

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^{4 Adapted with permission from the Electricity Engineers Association Safety in Design (Guide) 2016.}

5.0 Specific considerations when designing structures

5.1 Designing structures

This section provides information to designers of structures. A designer of structures is a PCBU whose profession, trade or business may involve them:

• preparing sketches, plans, calculations, specifications, instructions or drawings for a structure, including variations to a plan or changes to a structure
• making decisions for a design that may affect the health or safety of persons who fabricate, construct, occupy, use or carry out other activities in relation to the structure.

For the purposes of these guidelines, ‘structures’ means anything that is constructed, whether fixed or moveable, temporary or permanent, and includes:

• buildings, masts, towers, framework, pipelines, quarries, bridges, and underground works (including shafts or tunnels)
• any component or part of a  structure.

Design includes:

• the design of any part of the structure
• the alteration or modification of a design.

Design output includes:

• drawings in any form
• design detail
• design instruction
• scope of works documents relating to the structure.

The safe design of a structure will always be part of a wider set of design objectives, including practicability, performance, aesthetics, cost and functionality. These sometimes competing objectives need to be balanced in a manner that does not compromise the health and safety of those who work on or use the structure over its life, which includes the maintenance and/or demolition of the structure.

5.2 Systematic steps for designing structures

Designing structures is a process with a series of steps. These are separated into three distinct phases, which are explained in more detail below:

• pre-design phase
• conceptual and schematic design phase
• design development phase.

Once risks have been identified, designers need to work out how they will manage them.

Pre-design phase

Figure 8 illustrates what is involved in the pre-design phase, starting with identifying the purpose of the structure:

 

Consultation

The client should prepare a project brief that includes the safety requirements and objectives for the project. This will create a shared understanding of safety expectations between the client and designer.

The client should give the designer all available information relating to the site that may affect health and safety.

Designers should ask their clients about the types of activities likely or intended to be carried out in the structure, including the tasks of those who maintain, repair, service or clean the structure as part of its use.

Research

Information can be found from various sources to help with identifying, assessing and managing risks, including:

• HSWA and building laws, technical standards and WorkSafe or industry guidance
• industry statistics regarding injuries and incidents
• hazard alerts or other reports from: relevant statutory authorities, unions and business associations, specialists, professional bodies representing designers, and engineers’ research and testing done on similar designs.

Table 3 below illustrates some possible information sources for identifying hazards.

Step	Possible techniques
Initial discussions	Get information on the: purpose of the structure, including plant, ancillary equipment and  tasks industry injury profile and statistics and common risks and health and safety issues guidance from health and safety authorities and relevant industry associations, and standards known hazards and the consultation arrangements between the client and designer/design team.
Pre-design preliminary risk analysis	Useful techniques may include the client doing a combination of these things: holding workshops and discussions with people using or working on similar structures within the client company, including health and safety representatives holding an onsite assessment of an existing similar structure with feedback from its users researching information on similar structures, their associated hazards and relevant sources and stakeholder groups, then completing an analysis for their own design needs holding workshops with experienced people who will construct, use and maintain the new structure holding workshops with specialist consultants and experts in the health and safety risks using BIM (building information modelling) and other forms of modelling to view the physical and functional characteristics of the proposed structure. The Ministry of Business, Innovation and Employment (MBIE) website has some useful information about BIM and how this could be used throughout the design process. The use of digital information and modelling software applications like BIM in design development and delivery enhances the designer’s ability to anticipate, spot and foresee hazards and risks in the design. Designers can use these applications to enable locations, structures and plant to be accurately visualised, sequences of activity to be realistically demonstrated and construction programmes simulated.
Determine what risks are 'in-scope'	Workshops/discussions to determine which risks are affected, introduced or increased by the design of the structure.

Table 3: Information sources for identifying risks

Conceptual and schematic design phase

Risk identification should take place as early as possible in this phase. It is important that the risk identification is systematic and not limited to one or two people’s experiences of situations.

Broad groupings of risks should be identified before design scoping begins (Appendix B of these guidelines provides an indicative checklist of issues that should be considered). The designer and others involved should then decide which risks are ‘in scope’ of the steps of the risk management process, and should be considered in the design process. A risk is ‘in scope’ if it can be affected, introduced or increased by the design of the structure.

A system of work may also be classed as a risk if it is part of the construction method or intended use of the structure. The nature of the structure should also be taken into account.

Site of structure	Potential design issues that may cause health and safety risks are: how close the structure is to nearby properties or roads what the surrounding land is used for special clearances needed for construction equipment existing structures that may need to be   demolished nearby underground or overhead services nearby traffic flow condition of the work site safety of the public near the work site possible soil contamination and site stability.
Systems of work	Systems of work that could pose health and safety risks are: rapid construction techniques such as  prefabrication dangerous materials that are used in construction other work in the area vehicles and equipment used where there are  pedestrians restricted access for building and plant maintenance manual tasks that could cause injuries and health problems exposure to violence technical and human factors, including how the structure could be misused site access for construction workers and material storage, handling or work with high energy and health hazards.
Environmental or work conditions	adverse natural events such as cyclones, earthquakes and  floods poor ventilation or lighting exposure to extremes of temperature high noise levels poor welfare facilities.
Spatial planning and features	Appropriately sized amenities and facilities, including access, egress, space to perform tasks, fall prevention, confined spaces, surface treatments, sharp edges, height of features, roof pitch, material durability, site security, and traffic management.
Incident mitigation	The risks following an unexpected event or emergency due to inadequate egress, siting of assembly areas, and inadequate emergency services access.

Table 4: Framework for the preliminary risk identification

Design development phase

In this phase, the designer converts concepts for the structure into detailed drawings and technical specifications. They decide on control measures and prepare construction documentation. At that stage, the design is complete and can be handed to the client.

Figure 9 illustrates what this phase involves.

The primary legislative provision governing the design of buildings and structures in New Zealand is the Building Act and the New Zealand Building Code (Building Code). In addition, there are technical and engineering guidelines and standards produced by other government agencies, Standards New Zealand and relevant professional bodies. The main focus is to make sure that structures meet acceptable standards for structural soundness, safety, health and amenity.

The Building Code refers to New Zealand and Australia/New Zealand Standards, but designers should be aware that these may not adequately manage risks

if applied to a situation outside that contemplated in the Standard or if the Standard is out-dated. The Building Code also does not provide guidance for some specialised structures such as major hazard facilities (eg refineries).

Assessing risk

A risk assessment looks at what could happen if someone is exposed to a hazard, and how likely this is to happen. It is important that those involved in a risk assessment have the information, knowledge and experience of the work environment to make informed decisions.

If similar tasks or processes apply for a number of projects, a general risk assessment model may be appropriate. However, the designer is still responsible for ensuring that the generic assessment is valid for the project, before deciding to adopt it.

Table 5 outlines the design process

Step	Possible techniques	By whom
Identify solutions from regulations, good practice guidance and recognised standards	Talk with all relevant people to figure out which risks can be addressed with recognised standards. Plan the risk management process for other hazards.	Designer led. Health and Safety by Design team input. Client approval of decisions.
Apply risk management techniques	Further detailed information may be needed on risks, for example by: using checklists and referring to guidance material job/task analysis techniques. A variety of risk assessment measures can be used to check the effectiveness of control measures. These may be qualitative or quantitative. Scale models and talking with experienced industry members may be necessary to come up with solutions to longstanding health and safety issues.	Designer led. Client provides further information as agreed in the planned risk management  process. Health and Safety by Design team input.
Discuss design options	Take into account how design decisions influence risks when discussing control measure options.	Designer led. Client contributing. Health and Safety by Design team input.
Design finalisation	Check that the evaluation of control measures is complete and accurate. Prepare information about risks to health and safety for the structure that remain after the design process.	Designer led. Client and designer agree with final result. Health and Safety by Design team input.
Potential changes in construction stage	Make sure that changes which affect design do not increase risks.	Construction team in consultation with designer and client. Health and Safety by Design team input.

Table 5: The design process

Design considerations

There are different design options to manage risks throughout a structure’s lifecycle. Figure 10 illustrates these, and examples are given below.

Designers of new structures should design facilities such as lifting lugs on beams, or columns and protecting inserts in pre-cast panels, so they can be used for disassembly. Materials and finishes specified for the original structure may require special attention at the time of demolition, and any special requirements for the disposal and/or recycling of those materials or finishes should be described in the risk assessment documentation.

There are general risks that should be considered when designing structures. Designers should consider as many factors as possible to manage the health and safety risks they present. Appendix B outlines some common risks, and design considerations to manage them.

5.3. Reviewing control measures

As the design progresses and design decisions become more fine-tuned and detailed, there are still opportunities for managing risks. At various points in the design process, designers should review design solutions to confirm the effectiveness of control measures and if necessary, redesign to eliminate the risks so far as is reasonably practicable.

Wherever possible, design safety reviews should involve the people who will eventually construct the structure. If this is not possible, the client and designer should include people with knowledge and experience in the construction and maintenance processes in the design safety reviews. Their expertise will assist in identifying safety issues which may have been overlooked in the design.

Health and safety aspects of the design should be reflected in the requirements of contract documents for the construction stage and assist in the selection of suitable and competent contractors for the project.

On completion of construction, the effectiveness of Health and Safety by Design should be evaluated. This will help the designer to identify the most effective design practices and any design innovations that could be used on other projects. Feedback from users to help designers in improving their future designs for structures may be provided through:

• post-occupancy evaluations for buildings
• defect reports
• accident investigation reports
• information regarding modifications
• user difficulties
• changes from intended conditions of use.

6.0 Specific considerations when designing plant

6.1 Designing plant

This section provides information to designers of plant to be used at work.

Plant includes:

• machinery
• equipment
• appliances
• containers
• implements
• tools and components.

Examples of plant are illustrated in Figure 11 below.

This section also applies to the design of structures where items of plant are designed as a structural component or are assembled to form a structure.

6.2 Systematic steps for designing plant

Designing plant is a process with a series of steps. These are separated into two distinct phases, which are explained in more detail below:

• pre-design and concept development phase
• design development phase.

Once risks have been identified, designers need to work out how they will be managed.

Identifying health and safety risks

The first step in the risk management process is to identify all risks, so far as is reasonably practicable. Risk identification should be done as early as possible in the concept development and design phases. Risks relating to plant are often caused by the plant itself, and how and where the plant is used.

Risks may be identified by looking at the workplace and how work is carried out. Designers could talk to workers, manufacturers, importers, suppliers and health and safety specialists, and review relevant information, records and incident reports.

Table 6 lists things to consider when looking for plant risks.

Table 7 shows examples of potential plant risks and phases of the plant lifecycle after the design has been completed where people might be exposed to plant hazards.

Things to consider to identify plant risks
Risks	Can the plant cause injury or ill health from poor design? Can the plant cause injury from entanglement, crushing, trapping, cutting, stabbing, puncturing, shearing, abrasion, tearing or stretching? Can the plant create hazardous conditions from pressurised content, electricity, noise, radiation, friction, vibration, fire, explosion, temperature, moisture, vapour, gases, dusts, mists, fumes, ice, or hot or cold parts? Can the plant cause injury from lack of guarding of moving  parts? Can the plant cause injury as a result of unexpected  start-up?
Suitability	Is the plant fit for its intended purpose? What is likely to happen if it is used for a purpose other than the intended purpose? Are the materials used to make the plant suitable? Are plant accessories fit for their intended purpose? Is the plant stable? Could it roll over? If the plant is intended to lift and move people, equipment or materials, is it capable of doing this?
Access	Is access to the plant necessary when installing, using and maintaining the plant or in an emergency? Can workers access the plant safely without being injured by the plant or slips, trips and falls (eg by a walkway, gantry, elevated work platform or fixed ladder) or having to enter a dangerous environment to access plant?
Location	Does the plant affect the safety of the area where it will be located? Does the location affect the plant in a way that could impact health or safety (eg environmental conditions, terrain, airborne hazards and work area)? Will there be people or other plant nearby? What effect would this have?
Systems of work	Do the systems of work for the plant create risks? Does the plant’s safety depend on the competency of its users? Will users and others working near the plant need relevant training, information, instruction and supervision?
Unusual situations	What unusual situations or misuse could occur? What would happen if the plant failed? Would it result in loss of contents, loss of load, unintended ejection of work pieces, explosion, fragmentation or collapse of parts, release of substances hazardous to health, or other hazardous exposures? Is it possible for the plant to move or be turned on accidently?

Table 6. Things to consider when identifying plant risks. 

Potential risks

Phases of plant lifecycle

mechanical (eg crushing, cutting, trapping, shearing and high pressure fluids) electrical thermal noise vibration radiation – light, heat, electric fields, magnetic fields, radioactivity substances hazardous to health including chemicals, chemical by-products biological exposures (eg bacteria, molds, viruses) slipping, tripping and falling manual handling confined spaces hazards resulting from a combination of the above.

manufacture storage packing and transportation unloading and unpacking assembly installing commissioning using cleaning and adjustment inspection planned and unplanned maintenance or repair decommissioning dismantling disposal and recycling.

Table 7: Examples of plant risks and phases of the plant lifecycle

6.3. Design phase

Figure 12 illustrates what is involved in this phase.

Check if there are widely used control measures (eg industry standards) for common risks. However, just because something is a common practice doesn’t mean that it’s the most reasonably practicable option. You should focus on the most effective control measures. So before considering applying a widely used control measure, consider whether it will be effective in managing the risk in your situation (eg when working at height, will using mobile work platforms, rather than step ladders, more effectively minimise the risk?).

Technical standards

A plant designer may use technical standards, or a combination of standards and engineering, design, or ergonomics principles relevant to the design requirements (as long as the design meets regulatory requirements). Engineering principles could include mathematical or scientific procedures outlined in an engineering reference or standard.

Testing and examining plant

The designer should carry out any analysis, testing or examination that may be necessary to make sure the plant is without health and safety risks so far as is reasonably practicable.

Records of tests and examinations must be kept by the designer.

There are several different factors to think about when looking to identify and manage risks throughout plant’s lifecycle. Figure 13 illustrates some of these, and they are explained in further detail below.

There are general risks that should be considered when designing plant. Designers should consider as many factors as possible to manage the health and safety risks they present. Appendix B outlines some common risks, and design considerations to manage them.

6.4 Design information for the manufacturer

Designers should provide specific information to the manufacturer, so that the plant is manufactured following the design specifications.

If the manufacturer tells the designer there are health and safety issues with the design, the designer should revise the design to take account of these concerns, or they could tell the manufacturer in writing why revisions are not needed.

Designer information that can be provided to the manufacturer is in Table 8.

Manufacturing plant	specific conditions relating to the method of manufacture instructions for fitting or refitting plant parts and their correct location instruction where hot or cold parts or material may create a risk specifications of material specifications for components (eg ergonomically designed controls) wiring diagrams specifications for proprietary items (eg electric motors) component specifications including drawings and tolerances assembly drawings assembly procedures including specific tools or equipment to be used manufacturing  processes details of hazards presented by materials during manufacturing safety outcomes for programming.
Transporting, handling and storing plant	dimensions and weight handling instructions conditions for storage.
Installing and commissioning plant	risks from exposure to dangerous parts before guards are installed lifting procedures plant interacting with people plant interacting with other plant stability during installation the proposed method for installing and commissioning using special tools, jigs, fixtures and appliances necessary to minimise risk during installation concealed installations environmental factors affecting installation and commissioning that may present risk.
Using, inspecting, testing and decommissioning plant	intended uses for the plant including prohibited uses operating procedures safe entry and exit requirements for maintenance and repair emergency situations hazardous exposures including hazardous substances, exhausts, light, heat, noise, biological exposures how environmental conditions affect using the plant the results or documentation of tests carried out on the plant and  design de-commissioning, dismantling and disposing of plant known leftover risks that cannot be eliminated or sufficiently minimised by design details of control measures to further minimise the risks associated with plant information on administrative control measures requirements for special tools needed to use or maintain plant.

Table 8: Designer information that can be provided to the manufacturer.

6.5 Design verification of pressure equipment, cranes and passenger ropeways

The Health and Safety in Employment (Pressure Equipment, Cranes, and Passenger Ropeways) Regulations 1999(external link) require the design of this type of plant to be verified before it can be certified and first used.

For plant under these Regulations, the information that the designer should provide to the manufacturer should include the verified drawings and certification.

This provides evidence the plant design has been verified under the Regulations.

A design should only be verified by a competent  person.

The design verifier may be in-house or an independent contractor. They should not have been involved in the plant design process unless that PCBU has an accredited and documented quality system in place that has been certified by IANZ (or a body accredited or approved by the Joint Accreditation System – Australia and New Zealand).

6.6 Intended use of plant

The intended use of the plant, including its functions and limitations, can be determined by looking at:

• the expected place of use (eg environment and supporting surfaces)
• intended functions and operating modes
• safe use requirements including reasonably foreseeable misuse
• planned service life
• relevant standards and specifications (eg what is produced and materials to be used)
• possible malfunctions and faults
• testing, maintenance and repair  requirements
• the people interacting with the plant
• other products interacting with or related to the plant.

6.7 Design sources of human error

Poorly designed plant can lead to inadvertent or inappropriate actions from the people using the plant. Examples of these are in Table 9 below.

Untitended outcome	Possible causes due to poor design
Inadvertent activation of plant	Lack of interlocks or time lockouts. Lack of warning signs against activating equipment under specified damaging conditions.
Errors of judgement, particularly during periods of stress or high job demand	Critical displays of information are too similar or too close together, or visually difficult to see. Job requires user to make hurried judgements at critical times, without programmed back-up measures.
Critical components installed incorrectly	Design and instructions on installing components are difficult to   understand. Lack of configurations or guides on connectors or equipment.
Inappropriate use or delay in use of operator controls	Critical operator controls are too close, similar in design or awkwardly located. Readout instrument blocked by arm when making  adjustment. Labels on operator controls are confusing or missing. Information is too small to see from user’s position.
Inadvertent activation of operator controls	Operator controls can be activated accidentally. Lack of guards over  critical operator  controls.
Critical instruments and displays not read or information misunderstood because of clutter	Critical instruments or displays not in an obvious area. Displays look too similar.
Failure to notice critical signal	Lack of acceptable warning to attract user's attention to information.
Plant use results in unexpected direction or response	Direction of operator controls conflicts with normal operation
Lack of understanding of procedures	Instructions are difficult to understand
Folllowing prescribed procedures results in error or incident	Writted prescribed procedures are wrong and have not been checked
Lack of correct or timely actions	Available information incomplete, incorrect or not available in time. Response time of system or plant too slow for making the next correct action. Lack of automatic corrective devices with fast fluctuations.
Exceeding prescribed limitations on load or speed	Lack of governors and other parameter limiters. Lack of warnings on exceeding  parameters.

Table 9: Design sources of human error

7.0 Specific considerations when designing substances

7.1 What is hazardous substance?

A hazardous substance is any substance with one or more of the following properties, as described in Figure 14.

In addition, if a substance gains any of the above properties when it comes into contact with air or water, it is considered hazardous.

This section focuses on the design, redesign or modification of a substance.

7.2 Approval of hazardous substances

All hazardous substances that are manufactured in or imported into New Zealand need to be approved under the HSNO Act (Hazardous Substances and New Organisms (HSNO) Act 1996). The approvals are given by the Environmental Protection Authority (EPA). When a substance is approved, controls are applied to manage any risk that may arise during the substance’s lifecycle.

7.3 Control measures for managing substances

The specific control measures required by the Regulations may help manage the risks associated with manufacturing, using, handling or storing hazardous substances at work.

Depending on the hazardous properties of the substance these control measures may include specific requirements around:

• inventories
• safety data sheets
• emergency preparation and response plans
• labelling
• protective equipment
• fire extinguishers
• signage
• certified handlers
• compliance certification
• establishment of hazardous areas
• secondary containment (bunding)
• stationary container compliance certification
• tracking
• approved filler certification, and
• controlled substances licences.

A simple way to find out the key controls that apply to a substance is to use the hazardous substances calculator at: www.hazardoussubstances.govt.nz(external link)

Although these control measures apply when the substance is in the manufacture, use, handling or storage phases of the lifecycle, they should be given consideration during the pre-design and design stage, as the control measures are a critical element in the management of risk from the substance.

7.4 Design considerations for substances

The intrinsically hazardous properties of a substance may be unavoidable, if they are integral to the function of the substance at work. However, the principles of Health and Safety by Design should still be applied.

There are general risks that should be considered when designing substances. Designers should consider as many factors as possible to manage the health and safety risks they present. Appendix B outlines some common risks, and design considerations to manage them.

7.5 Inherently safer substances

When designing and developing safer substances, the designer needs to find a balance between eliminating, then minimising health, safety or environmental risks, and maintaining the effectiveness of the substance. If a less hazardous version of the substance is designed that is not as effective as those currently being used, the health and safety benefits may outweigh this reduction in effectiveness.

8.0 Case studies

8.1 NZTA's Waterview connection project

Set the scene

This was the largest civil engineering project in New Zealand at the time of construction between 2011-2017. It comprised:

• 5 km long, 3-lane (each way) motorway comprising 35 kilometres of lanes
• two 2.4 km long 13.1 m (ID) diameter bored tunnels and ventilation buildings
• six road bridges – 1,700 m total length
• two long span footbridges and several smaller structures
• over 3 km of retention structures up to 30 m high
• extensive urban improvements and landscaping
• 5+ years construction period
• operations and maintenance responsibilities for 10 years
• delivered to NZTA for $1.4 billion capital cost.

What went wrong and what went right?

Safety in Design (SiD) was implemented on the project from the tender design phase. It was a formal process that was documented in the design management plan and applied throughout the design and delivery period.

A risk based approach was used, where workshops were held in the early stages of design with participation from design, construction and operations personnel. This was so that a range of knowledge and experience was present and consideration was given to the full life cycle. The workshops identified safety-related risks for all elements of the project that could be mitigated, to at least some degree, through smart design. An SiD register was maintained to capture and monitor the treatment of those safety risks throughout the design phase, and also to capture the transfer of any residual risk at the end of design to construction and ultimately to operations. Design reports also specifically documented SiD considerations and treatment.

This approach was successfully applied across the project with a number of key design decisions driven by safety considerations.

Two examples of SiD related outcomes from the project:

1. Selection of the tunnelling method and the decision to go with a Tunnel Boring machine (TBM) was driven in large part by risk mitigation and safety considerations. The TBM method meant all workers and equipment were shielded within the TBM shield or permanent lining which removed the risk of exposure to collapse or inundation. The TBM method itself also reduced the risk of collapse and inundation from occurring, mitigating risk to surface infrastructure and facilities

2. The southbound motorway approach into the northern portal of the tunnel has two lanes coming from each direction (east and west) merging into three lanes into the tunnel (ie three lanes merging into four lanes). This means the outside lane from each direction has to merge with the one coming from the other direction. The tunnel approach is all on elevated viaduct and comprises a merging ramp approaching from each direction with concrete side barriers. The barriers meant visibility to traffic on the adjacent merging ramp would have been restricted until very late in the merge process. A decision was made to improve the pre-merge visibility by using barriers on the merge side of the ramps with a rail on the top to reduce the height of concrete and therefore improve cross ramp visibility (by making the tops of the barriers ‘see-through’). Furthermore, where the two ramps connected, an additional piece of infill slab was constructed that allowed the barriers to be removed completely.  This  further improved visibility between  traffic in the merging two lanes.

What lessons can we take from this project and share with the industry?

• Implementation of a SiD process early in the design period means real safety improvement outcomes can be achieved.
• Participation of people from differing design disciplines as well as beyond the overall design discipline, such as constructors and operations personnel, is extremely beneficial and should be encouraged and accommodated if
• at all possible.
• A risk based approach works well in terms of identifying and ranking the risks as well as tracking the treatment and transfer of safety related risks.

Acknowledgement

Thanks to the NZTA and The Well-Connected Alliance for allowing this case study to be used. Also thanks to Peter Norfolk of Tonkin & Taylor, who was the Civil Design Manager for the Waterview Project.

8.2 Queenstown weather mast – weather reporting system

Set the scene

The introduction of night time flights into Queenstown airport showed the need for accurate reporting of the local weather. The weather reporting system filled the need by using weather stations located around the Queenstown basin.

These stations measure the wind speed and direction, temperature and humidity, and report to a main computer server through the cellular phone system.

The information is then made available to pilots, air traffic controllers and flight planners via the Internet. The information can also be sent to pilots whilst in flight.

The system was being upgraded to improve its robustness and reliability. This included replacing the masts used to support the system instruments. The masts require bespoke foundations and mounting plates. An additional complexity is that some of the weather stations are sited in remote hilltop locations with limited and difficult access.

The mast foundation is a concrete-filled hole in the ground with 4 threaded rods embedded. Each mast has a base plate fitted to the bottom. This base plate has holes which slide over the threaded rods, allowing the base plate to be secured with nuts and washers. The mast is assembled on site, with all instruments and cables attached whilst the mast is horizontal. The mast is then manually raised into the upright position, with the base plate sliding over the threaded rods as the mast reaches the vertical position.

What went wrong or what went right?

The original plan was to steady the base of the mast with a person’s foot as the mast was raised. Whilst this traditional method would work, a quick risk assessment showed there was a high likelihood of the person’s foot slipping off the base of the mast resulting in an uncontrolled movement of the mast and possible damage to the mast and instruments or worse, injury to people.

The base plate was therefore redesigned to consist of 2 hinged plates. This allows one plate to be affixed to the mast as before, and the other plate to be attached to the foundation threaded rods whilst the mast is still in the horizontal position. The mast can then be raised to the vertical position in a fully controlled manner with no chance of the mast base slipping. Once the mast is upright the hinged plates are securely bolted together. This design also ensures the mast base cannot slip when the mast is lowered for periodic instrument maintenance.

A simple, low cost design change has effectively eliminated a potential hazard.

An early risk assessment has presented an opportunity to change a design to increase the safety of the system throughout its life in a cost effective manner.

Thanks to Navigatus Consulting for allowing this case study to be used.

8.3 Compac service trolley

Set the scene

A service trolley was positioned above a fruit sorter. The fruit sorter has fruit conveying carriers attached to chains running at high speed. This unintentionally gave access to multiple nip points and hazards in the machine, which were otherwise not accessible. There was also a danger of falling from height through the machine and onto the floor.

The purpose of the trolley position above the machine is:

• For trained personnel to conduct cleaning/routine maintenance when the machine is shut down and locked out. This task needed the personnel to be able to lie on the trolley floor and reach the machinery components below.
• To give unauthorised personnel a platform to observe operations while the machine is running. For this the trolley needed to prevent access to all the moving parts underneath.

What went wrong or what went right?

The existing trolley was modified to incorporate the flexibility required for cleaning and maintenance tasks, while addressing the safety concerns identified by the risk assessment. This meant that the trolley needed to be configurable to be used in two distinct modes of operation. This was achieved through the installation of adjustable infill panels and the application of strict administrative controls.

• Cleaning/maintenance mode (panel infills folded down): This mode gives access to the parts below the trolley, but mostly requires the machinery to be switched off and locked out first.
• Observation mode (trolley panel infills lifted and secured in place): Prevents access to moving parts on an operating machine.

What lessons can we take from this project and share with the industry?

While the new trolley configuration provided safer access for maintenance staff and observers during standard operation, we learned that we must remain vigilant regarding unintended uses of the trolley at all lifecycle stages, such as machine installation onsite. For example, in one instance, the trolley started being used as an anchor point to protect installers while working at height. This would have been dangerous as the trolley is ill-equipped to be an anchor point and might have led to an incident.

Thanks to Suhas Shanbhogue of Compac for allowing this case study to be used.

8.4 Auckland Council special housing area: stormwater upgrade

Set the scene

Installation of new stormwater infrastructure to increase capacity and make allowance for a special housing area and an additional catchment. The project will also allow for separation of the combined wastewater/stormwater network.

What went wrong or what went right?

The catchment being serviced was located on a ridge with the downstream network located at a much lower elevation (a drop of 22 m over a 90 m length). The initial design called for a 24 m deep manhole in order to comply with the Stormwater Code of Practice.

A Safety in Design workshop was held with attendance by the designers, the Auckland Council Operations Team and the Auckland Council Design Team. The workshop identified safety issues with operating and maintaining such a deep manhole. Safety issues were also raised around the construction of such a deep structure. The designers were asked to redesign the alignment to remove the deep manhole. The removal of the deep manhole eliminated the safety concerns regarding working at depth during construction and operation.

In order for the design to be accepted, Auckland Council, in collaboration with the designers, relaxed the design criteria, specified more durable products and agreed to the design of an energy dissipation chamber. These changes were required in order to incorporate the shallow manhole and associated steeply graded pipe and high velocity flows.

What lessons can we take from this project and share with the industry?

In order to design and build a safe asset both the client and designer need to be prepared to think outside the box and investigate alternative products, installation methodologies and solutions.

Acknowldgement

Thanks to Auckland Council for allowing this case study to be used. Also thanks to Stantec (formerly MWH), who were the Design Consultants for this project.

8.5 Noise control for shearing clippers

Set the scene

Shearing equipment can generate high levels of noise during the shearing of sheep, meaning that shearers can be exposed to high noise levels for long periods during the season. Extended periods of exposure to high levels of noise can lead to temporary or permanent hearing loss. This may be partial or full.

What went wrong or what went right?

Research completed at Canterbury University demonstrated that noise levels could be reduced by simple redesign of the shearing equipment, such as the prevention of the core hitting the downtube. This was a simple, inexpensive and reasonably practicable fix to reduce the noise emission to shearers and minimise a health and safety risk.

Thanks to John Wallaart (Principal Advisor Biological and Chemical, WorkSafe New Zealand) for providing this case study.

Appendices

Appendix A: Glossary (PDF 46 KB)

Appendix B: General risks to consider when designing structures, plant or substances (PDF 173 KB)

Appendix C: Health and Safety by Design checklist for structures (PDF 49 KB)