Temporary works design brief: how to prepare one in Australia

A temporary works design brief is the document that tells the designer what the works are for, what the site is like, what constraints apply and what you need back. In Australia it rests on the duty of whoever commissions construction work to consult the designer and pass on the site information they hold, and on contract specifications such as a South Australian road agency's, which asks for a brief that follows the temporary works risk guidance published through Engineers Australia. By the end of this article you will know what an Australian brief should carry, who prepares and signs it, where the CFR, DCR and ER risk categories fit, and what to ask the designer to return.

Why the brief matters

UK guidance for inspectors from the Health and Safety Executive (HSE) lists an inadequate or missing design brief among the main causes of temporary works failures, and notes research finding briefs were often unclear on key points such as ground conditions [1]. That guidance is from overseas, but the mechanism is the same on any site: the designer can only design for the conditions they are told about. If the brief is silent on a service trench beside the excavation, a stockpile on the edge or the pour rate planned for the day, the design will be silent on them too.

The HSE guidance also makes the brief the reference point for everything that follows: the calculations, the drawings and any later change [1]. When a question comes up on site, the brief is where you check what the designer was told.

The Australian footing

In Australia the expectation of a brief comes from three places.

The WHS duties. Safe Work Australia's model Code of Practice for the safe design of structures treats a structure as anything constructed, temporary or permanent, and names engineers designing formwork, falsework, scaffolding and sheet piling among the designers with duties [2]. Under the model WHS Regulations, a person conducting a business or undertaking (PCBU) who commissions construction work must consult the designer, so far as is reasonably practicable, about eliminating or minimising design related risks (regulation 294), and the designer must give that person a written safety report on the hazards specific to the design (regulation 295) [2]. The Code says the commissioning party should give the designer a brief with the safety requirements, all available site information that may affect health and safety, and the hazard information it holds [2]. Check the version of the Code your state or territory has approved.

The regulators' codes and guides. These describe what the designer has to consider for each kind of works, and so what your brief has to tell them. Examples are below.

Contract specifications. The South Australian Department for Infrastructure and Transport's temporary works specification, PC-CN4 (version 1, September 2024), requires the contractor's design or construction management plan to include a design brief template meeting the minimum requirements of the Engineers Australia Temporary Works Risk Guidelines [3]. It requires the temporary works coordinator (TWC) to make sure the brief reflects the actual site, the residual risks, the assumed construction method and the loading constraints from the permanent works designers [3]. Where the works interface with a third party asset, the third party reviews the brief and the contractor addresses its comments and resubmits [3]. That specification applies to its own contracts, but it is a clear published statement of what an Australian client can expect a brief to do.

Who prepares it and who signs it

The TWfAU guidance has the client prepare the brief and the temporary works designer review it and respond, and says the permanent works designer should brief the temporary works designer directly where appropriate [6]. On site, the TWC is responsible for the brief, even when a site engineer or project engineer drafts it. The UK guidance says the TWC should make sure an adequate brief reaches both the designer and the design checker, and that any change the designer proposes comes back through the TWC [1]. The SA specification puts the same responsibility on the TWC for its contracts [3].

The CITB brief template from the UK ends with sign off by the brief's originator and the TWC [4]. A practical Australian equivalent is: the author, the TWC, and where your contract requires it, the client's representative or the third party asset owner.

The risk categories: CFR, DCR and ER

The Temporary Works Forum Australia (TWfAU), a community of practice within Engineers Australia, publishes Temporary Works Risk Guidance: a clients' guide adapted from the UK Temporary Works Forum's 2014 guide, offered as a free download [5] [6]. It proposes three risk categories, to be set and communicated by the client during the design brief process [6]:

Category	What it describes	Range in the TWfAU guidance
CFR, consequence of failure risk	What could happen if the works fail, given their nature, location and what is nearby	Four categories, CFR0 to CFR3
DCR, design complexity risk	How complex the design is, which sets the design checking regime	Six categories, DCR00 and DCR0 to DCR4
ER, execution risk	How likely failure is through use, workmanship or materials, from erection to removal	Four categories, ER0 to ER3

Three points from the guidance bear directly on the brief [6]:

Every brief states the CFR, with an explanation. Where the CFR is CFR2 or CFR3, the guidance expects the DCR to be raised.
DCR00 is the only category without a brief. It covers items a competent site team can manage without design, by custom and practice and an industry standard safe system of work, and only where the CFR is CFR0 or CFR1. Everything from DCR0 upwards needs a brief, scaled to the scheme.
The designer answers execution risk in the output. The guidance expects the designer to state the controls and hold points needed to manage the ER, and site teams can add more.

The SA specification uses the same three categories [3]. In it, CFR2 and CFR3 call for evidence that both the permanent and temporary works designers have considered the risk, the management plan must say how the DCR is set and changed as the design develops (the specification gives the range as DCR0 to DCR4), and controls and hold points must let those building, using and removing the works manage the ER [3].

In practice the brief should state the proposed categories and the reasons for them, so the designer and checker can challenge them before design starts. The categories are a judgement made by the people responsible for the works, not a calculation.

How TworkX works shows where the categories are proposed and reviewed before a brief is issued.

What the brief should carry

The TWfAU guidance includes a return design brief template with two columns: what the client requests, and the designer's response [6]. The designer's response becomes the design statement, which the guidance expects for DCR1 and above [6]. The CITB template from the UK is another useful skeleton [4]. Drawing on both, a brief covers:

Project and contacts. The project, the brief reference and revision, the date issued and the date the design is needed, and the site contact.
Scope. What the temporary works are, what they support or protect, and where they start and stop. Say what is excluded.
Responsibility. The TWC, the designer, the checker, and who releases each hold point.
Risk categories. The proposed CFR, DCR and ER, with reasons. The TWfAU guidance says every brief should state the CFR [6].
Existing information. Drawings of the permanent works, survey, geotechnical reports, service searches and potholing results, and any existing structure records.
Constraints. Loading limits from the permanent works designer, sequence and hold points, programme, plant, access, neighbours, third party asset conditions and permits.
Standards and specifications. The documents the design must comply with, named by reference, including the project specification.
Preferences. Any preferred method, system or equipment, and whether it is available. Say if you are open to alternatives.
Deliverables. What you need back, and when.

The template's deliverables section is worth copying closely: a drawing or specification suitable for construction, a schedule of significant residual risks, the sequence, inspection and hold point details the contractor needs for a safe system of work, and a completed design and check certificate [4]. In Australia, the regulation 295 safety report belongs on that list too [2].

What each kind of works needs

The regulators' documents show what the designer must consider, which tells you what to gather. The brief supplies the facts and the designer chooses the values. The examples below cover excavation, formwork and falsework; TworkX's modules follow the same approach for each kind of works, scaffolding included.

Excavation and trench support

Safe Work Australia's excavation code says safe design depends on a thorough investigation of the ground before work starts, and that a geotechnical engineer may need to report on soil conditions, support, dewatering and stability [7]. It lists soil type and strength, moisture, whether ground is natural or backfilled, faults and layering, and how conditions change with rain or a shifting water table [7]. It also covers groundwater and nearby drains, the depth of footings of adjacent structures, underground services checked on site rather than taken from records alone, and loads near the edge from vehicles, plant and spoil [7]. Excavation below the footing level of a nearby structure needs assessment and a support system designed by a competent person [7].

Formwork

The SafeWork NSW formwork code lists what the designer considers: the erection and stripping method, the system and its layout, the most adverse combination of loads including people, plant and weather, the pour sequence and rate, the concrete mix and admixtures, the ground or structure the formwork bears on, stability and backpropping during stripping, edge protection, access, crane lifts and the construction sequence [8]. Most of those depend on information the site team holds or decisions it makes. SafeWork NSW also issued an alert in November 2024 about a rise in inadequate formwork designs and certifications, calling for a site specific installation design before work starts and an approved, documented process for any change [9].

Falsework

Safe Work Australia's falsework guide calls for a site specific geotechnical investigation by a competent person for the falsework itself, separate from the one for the permanent structure [10]. It also says that on complex structures the structure designer should involve the falsework designer early to reduce complexity and risk [10]. Your brief should say what ground information exists, what is still to come, and how the permanent works designer has been involved.

What to hold back from the brief

The brief describes the problem. It should not carry design values: no member sizes, assumed capacities, allowable bearing values or pressures picked from a table. If a value is known from a report, attach the report and say where it came from. If it is not known, say so and ask the designer to state the assumption they adopt. A brief that guesses values hands the guess to the designer as a fact.

A checklist before you issue

Check	Done
Scope, limits and exclusions stated
TWC, designer and checker named
CFR, DCR and ER proposed with reasons
Permanent works loading constraints obtained
Ground information attached, or its absence stated
Services located on site and recorded
Adjacent structures, footings and third party assets listed
Plant, stockpiles and access near the works described
Sequence, hold points and programme stated
Standards and project specification named
Deliverables and dates listed, including the safety report and certificate
Third party review arranged where required
Signed by the author and the TWC

To see what a finished brief can look like, download the sample brief, prepared for a fictitious trench. TworkX helps site teams turn this information into an issuable brief for the designer.