What information does a temporary works designer need?

A temporary works designer needs to know what the works must do, what they will stand on or retain, what loads and activities they will see over their life, and what is around them. Australian regulators set this out type by type: the excavation code centres on the ground, services and neighbouring structures, the formwork and falsework guidance centres on loads, pour and foundations, and the scaffolding guidance centres on duty, ties, wind and what the scaffold bears on. This article answers the question of what information a temporary works designer needs for each of those four kinds of works, with a table for each that you can use to gather it before you brief.

What information every temporary works designer needs

The UK Health and Safety Executive (HSE) puts the basic test simply: temporary structures must be designed for the loads that can be foreseen and used only for the purpose they were designed for [1]. The designer cannot foresee a load nobody mentions. Everything below is the detail of those two ideas: what the works are for, and what will act on them.

In Australia there is also a legal reason to pass information on. Safe Work Australia's excavation code notes that the person commissioning construction work must give the principal contractor the hazard and risk information they hold, and that designers give the commissioning party a written report on design hazards that affect construction workers [2]. SafeWork NSW's formwork code goes further for formwork: consulting the designer has to include passing on known hazards and risks at the site, and the principal contractor, working with the permanent works designers, should give the formwork designer all relevant information that could affect the design [3].

Across all four kinds of works, the designer needs:

The purpose and scope. What the works support, retain or give access to, and where they start and stop.
The period of use. How long the works will be in place, and the stages they pass through, including removal.
The ground or structure they bear on. What is known about it, and what is not.
The loads and activities. People, plant, materials, weather and anything stored or attached.
The surroundings. Neighbouring structures, services, traffic, powerlines and third party assets.
The method and sequence the site intends to use. Including any preferred system or equipment.

The Temporary Works Forum Australia (TWfAU), a community of practice within Engineers Australia, adds three points in its Temporary Works Risk Guidance, a clients' guide adapted from the UK Temporary Works Forum's 2014 guide and offered as a free download [8]:

Be specific. The brief has to say which information the design is to use. Giving the designer access to a document store and leaving them to search it is not enough [8].
Look at what is nearby. The designer reviews whatever is in the location of the works or close enough to affect them or be affected by them, such as soil, other excavations and temporary works, fixed assets, passing vehicles, crowds and water, and the brief should make clear how each bears on the design [8].
Answer the designer's questions. The designer judges whether the information is current and sufficient and asks for more if not. The guidance says those requests go to the client or project manager for action and must be honoured [8].

It also says the designer should be told about preferences and constraints on materials and components, their delivery and handling, site access and crane capacity, programme timing, and the need for safe access for inspection and maintenance [8].

Where an item is unknown, say so. A designer told that ground information does not exist yet can plan for it. A designer told nothing may assume something that is not true.

Excavation and trench support

Safe Work Australia's Excavation work code of practice (March 2015) does not give one checklist, but its sections on planning, services, loads and ground collapse cover the following [2]. The method of ground support, whether benching, battering, shoring or shielding, is designed or selected by a competent person such as an engineer or geotechnical engineer [2].

Information	Why the designer needs it	Where it usually comes from
Excavation type, depth, plan shape and how long it stays open	Changing conditions over time affect stability	The method statement and programme
Soil and rock: type, strength, moisture, fill or natural, faults and seams	Ground conditions govern the support	A geotechnical report, if one exists
Groundwater, nearby watercourses, drains and run off	Water pressure and dewatering change the design	The geotechnical report and site observation
Adjacent buildings, retaining walls, tanks and trees, with footing depths	Digging below a footing needs assessment and designed support	Survey, existing drawings and site inspection
Underground and overhead services	Records can be wrong, so services may need exposing by potholing	Service searches and potholing results
Plant, spoil, vehicles and stored materials near the edge	Loads within the zone of influence act on the support	The plant list and site layout
Vibration sources such as piling, traffic or vibrating plant	Vibration affects stability and nearby sensitive structures	The programme and neighbouring works

The code puts the duty to obtain current underground services information on the person with management or control of the workplace, before excavation starts, and to give it to the people doing the work [2]. That makes the service information one of the first things to gather, not one to leave to the designer.

Formwork

SafeWork NSW's Code of Practice: Formwork (March 2021) lists what the formwork designer considers [3]. Most of it depends on decisions the site team makes.

Information	Why the designer needs it
The element geometry and the construction sequence	The method and sequence have to suit the building design
Pour sequence and the planned rate of placement	The design sets maximum pour rates and allows for uneven loading
Concrete mix design and admixtures	The mix and admixtures affect the formwork
What the formwork bears on, and the drainage around it	The ground or structure below must carry the full loads, in wet weather too
Stripping timing and any backpropping	Stability during stripping depends on curing and propping
People, materials, equipment and storage on the deck	The design covers the most adverse combination of loads
Crane and lifting arrangements	Lifting points and methods are part of the design
Edge protection, screens and anything to be attached	Added screens or components can need new calculations
Adjacent structures and powerlines	The design allows clearance to them

On ground in particular, the code says principal contractors must provide information on factors that may affect ground stability, before the formwork goes up or while it is in use [3]. SafeWork NSW also issued a safety alert in November 2024 after seeing more inadequate formwork designs and certifications, calling for a site specific installation design before work starts [4].

Falsework

Safe Work Australia's Guide to falsework (July 2014) is the national guidance on falsework [5]. Its points for the site team are:

Every stage of use. The design covers the loads across all stages, so the designer needs the sequence of erection, loading and removal [5].
Ground. A site specific geotechnical investigation by a competent person is needed for the falsework, in addition to the one for the permanent structure [5]. Saturated ground can weaken support or lift footings, so drainage and any chance of the footings being submerged matter [5].
Traffic and the public. Where falsework is over roads, railways or footpaths, the designer needs to know, because controls such as exclusion zones, closures, catch platforms and screens may be needed [5].
The permanent works designer. On complex structures, the guide says the structure designer should involve the falsework designer early to reduce risk during construction and dismantling [5]. Tell the falsework designer what has been agreed with the permanent works designer, including any loading constraints.
Proprietary systems. Off the shelf systems generally need to form part of a specific design to be suitable for complex falsework [5]. If you have a system in mind, name it and say whether it is available.

Scaffolding

Two Australian documents set out what the scaffold designer considers: Safe Work Australia's General guide for scaffolds and scaffolding work (July 2014) [6] and the Queensland Scaffolding Code of Practice 2021 [7]. Many scaffold types need design verification by an engineer under the Queensland code, including cantilevered, hung, suspended, tall tower, gantry, loading bay, public access and demolition scaffolds [7].

Information	Why the designer needs it
What the scaffold is for, the working levels and the platform duty	Duty ratings suit different tasks and loads, and using more working levels than designed can overload a scaffold [6] [7]
What it stands on, and its condition	The foundation or supporting surface must carry the loads; Queensland expects the ground to be assessed in writing, and engineering advice for unusual surfaces such as verandas, slabs and parapets [6] [7]
What it ties to, and whether the structure can take the load	Tie positions and anchor types are part of the design, and the supporting structure may need propping [6] [7]
Location and exposure, including cyclone regions	Wind severity depends on location and terrain [7]
Sheeting, shade cloth, mesh, screens or signs	They add wind and dead load and need the designer's input before they are fitted [6] [7]
Hoists, loading platforms, lifting points or crane lifted sections	These are designed by an engineer and can need extra ties [7]
Powerlines, traffic and mobile plant nearby	They need exclusion zones, barriers or re routing, and the design should avoid protrusions [7]
Access and emergency egress	The access system must suit the loads expected in an evacuation [7]

What the designer does not need from you

The designer needs facts, not design values. Do not pick member sizes, ground capacities, pressures or tie spacings for the brief. If a value comes from a report, attach the report and say where it came from. If it is unknown, say so and ask the designer to state what they assume. A guessed value written into a brief tends to be treated as a site fact.

Keep standards out of the detail too. Name the standards and the project specification the design must meet, by reference, and leave their application to the designer.

Putting it into a brief

The tables above are the information. The brief is how it reaches the designer: one document, with the scope, the risk categories, the attachments and the deliverables you need back. The TWfAU guidance treats the brief as two parts, the commissioning party's requests and the designer's response to them, so expect the designer to come back with questions before design starts [8]. How it works shows the steps TworkX follows from site information to an issued brief, the modules page lists what each of the excavation, formwork and falsework, and scaffolding modules asks for, and the sample brief shows a finished one for a fictitious trench.

TworkX helps site teams gather this information and issue it as a brief for the designer.