Temporary Works Design in Construction Explained

Most people think of construction as the permanent thing being built — the walls, floors and frame that will stand for decades. But almost every permanent structure depends, while it is being built, on a parallel structure that nobody ever sees in the finished building: the temporary works. Temporary works hold back the ground, support fresh concrete, brace incomplete structures and keep workers safe, and when they fail the consequences are often catastrophic. This article explains temporary works design and why it deserves serious engineering attention.

Temporary works are the structures provided to support or protect a permanent structure during construction, or to support construction plant and operations, and which are removed once they have done their job. Designing them well is every bit as much engineering as designing the permanent building — arguably more demanding, because temporary works carry high loads in changing conditions and have less margin for error.

What temporary works are

Temporary works encompass a wide family of structures: excavation support that holds back soil and groundwater, formwork and falsework that support concrete until it gains strength, propping that braces a structure mid-construction, scaffolding that provides access and working platforms, and the foundations and platforms that support cranes and heavy plant. What unites them is that they are temporary — present only during construction and removed afterwards — yet they must be fully adequate while they are in place.

The paradox of temporary works is that being temporary makes them more, not less, dangerous to underdesign. They are often subjected to the heaviest loads of the whole construction process — the full weight of wet concrete, the pressure of retained soil, the surcharge of stacked materials — at the very moment the permanent structure cannot yet help carry them. The same engineering principles that govern permanent structures, described in our overview of what a structural engineer does, apply here with full force.

Why temporary works matter so much

Construction-stage failures are among the most serious in the industry, and a large share of them involve temporary works. Excavations collapse and bury workers; falsework gives way under wet concrete and brings a floor down; inadequate propping lets a partially built structure buckle. These events happen during the build, when people are working in and around the structure, so the human consequences are immediate and severe.

Because the loads are real and the margins are tight, temporary works must be designed, checked and managed with the same rigour as the permanent structure — sometimes more. The history of construction accidents has repeatedly shown that treating temporary works as a contractor’s afterthought, rather than as engineered structures in their own right, leads to disaster. Concrete behaviour matters a great deal here, which is why our guide to reinforced concrete is relevant background to the formwork and falsework that support it.

Common types of temporary works

Several categories of temporary works appear on almost every project. Excavation and earth-retention systems — sheet piling, soldier piles, contiguous or secant bored piles, and bracing or anchoring — hold back the ground so that basements and foundations can be built safely. Formwork and falsework give wet concrete its shape and support it until it is strong enough to be self-supporting. Propping and shoring stabilise existing or partially built structures, including during alteration and demolition.

Other common temporary works include scaffolding for access, crane and plant foundations, hoarding and edge protection, and the dewatering systems that keep excavations workable. Each is a structure that must be designed for the loads it will actually see — and those loads, such as the hydrostatic pressure of fresh concrete on formwork, are often larger and less intuitive than people expect.

The engineering behind temporary works

Temporary works design follows the same logic as permanent design: identify the loads, choose a structural system to resist them, size the members, and check the system against failure and excessive deformation. The difference lies in the loads and the conditions. The designer must consider construction loads, the pressure of wet concrete, soil and groundwater pressures, wind on tall temporary structures, the surcharge from stacked materials and plant, and the changing conditions as work proceeds and elements are added or removed.

Crucially, the sequence matters. A temporary works scheme is not just a set of members; it is a plan for how loads are carried at each stage of construction, including when supports are struck. Striking formwork too early — before the concrete has gained enough strength — is a classic and dangerous error. Good temporary works design therefore specifies not only what to build but when it is safe to remove it.

Managing temporary works on site

Design is only half the story; temporary works must also be managed properly on site. Responsible practice assigns clear responsibility for temporary works, ensures the design is checked appropriately for its risk level, and confirms that what is built on site matches what was designed. A perfectly sound design is worthless if the propping is installed incorrectly or the formwork is struck before the concrete is ready.

This is why temporary works are increasingly treated with formal coordination — a designated temporary works coordinator, design checks proportional to risk, and inspection before loading. The discipline is to give temporary works the same seriousness as the permanent structure, because a failure during construction can be just as deadly as a failure in service. Demolition relies heavily on temporary support too, which links this topic to our broader structural-safety work.

Frequently asked questions

What are temporary works in construction?

Why are temporary works so important for safety?

Temporary works often carry the heaviest loads of the construction process at the moment the permanent structure cannot yet help, and people work in and around them. A large share of serious construction failures, such as excavation and falsework collapses, involve inadequate temporary works.

What are common examples of temporary works?

Common examples include excavation and earth-retention systems, formwork and falsework supporting wet concrete, propping and shoring of existing or partial structures, scaffolding for access, crane and plant foundations, and dewatering systems for excavations.

Who designs temporary works?

Temporary works are engineered structures and should be designed and checked with the same rigour as permanent structures, by qualified engineers, with checks proportional to the risk. On significant works this falls within the remit of a Professional Engineer rather than being left to a contractor’s judgement alone.

Why is the sequence of temporary works important?

Temporary works carry loads differently at each stage of construction, and removing supports at the wrong time can cause failure. Striking formwork before the concrete has gained enough strength is a classic and dangerous error, so the design must specify when it is safe to remove each support.

Have a project where excavation, propping or falsework needs proper engineering? Talk to our consultancy or get in touch.