Who prepares the structure

Each option has a consequence, and the third is the default position. By default every tenderer measures for itself.

Preparer	What they bring
The designer	knows the solution and holds the drawings
The client or its adviser	knows the budget and the requirements
Each tenderer separately	the default where no one else does it

The third option is the most expensive overall, even though it never appears as a separate line on anyone's invoice: the cost is spread across all the tenderers and comes back in the prices, as covered by the article on duplicated work. The cost is spread across the tenderers.

The argument is clearly formulated in professional literature, and it reaches beyond budgeting. Its effect runs through the whole procurement.

According to professional sources, where the preparer of the preliminary design draws up a list of the construction works ahead and their calculated quantities, an overview of the future building is then available to the preparer, to the client and to the tenderer alike. Three parties therefore get the same picture, which is the core of the whole argument.

According to the same source, it also emerges early where the architect has, at the client's request, designed a particularly complex or unusual junction or structure, since in that case it must be pointed out at an early stage of planning. Drawing up the schedule is therefore also a check on the design, and a complex junction that appears only when tenders arrive is more expensive than one that appears during design.

Each gains something different, and the third party's gain is larger than it first appears. It concerns smaller companies.

Party	What they gain
The designer	sees whether the solution is buildable and reasonably priceable
The client	comparable tenders and knowledge of what is inside the price
The tenderer	saves the time of quantity take-off and gains certainty that competitors are pricing the same content

A tenderer no longer risks losing to a competitor who allowed for less. That is a common fear in construction, and it raises every tenderer's risk allowance.

Three obstacles, all of them solvable, and the third is the most frequent. It concerns who pays for the work.

The design contract does not provide for this work, so no one does it. The designer may not be competent in budgeting, which is a separate discipline. And the client does not know to ask for it.

The first is the most easily removed: the work must be written into the design contract. According to professional sources, the client's awareness and requirement is the lever that should move matters towards a common tender form, and the same source notes that such a description might be expected from a standard or from guidance documents where tenders for large-scale works are being prepared.

One possibility, little used.

A separate estimator or construction measurement service, who prepares the schedule and the quantities from the design. It is a separate discipline, which does not require budgeting competence from the designer, and the cost is a one-off spread across all the tenders, as covered by the article on what a budget costs.

The practical conclusion is short: if the designer does not do it, that does not mean no one can. It can be commissioned separately.

The structure is prepared either by the designer, by the client or by each tenderer separately, and the last option is the most expensive overall even though it appears on no one's invoice. According to professional sources, a schedule of works and quantities prepared by the preliminary designer gives the same overview to the preparer, the client and the tenderer, and it brings complex junctions out during design rather than when tenders arrive. Three obstacles stand in the way, all solvable, and the simplest solution is to write the work into the design contract.

Four rules: write the preparation of the schedule of works and quantities into the design contract. Treat drawing up the schedule as a check on the design as well. Explain to the tenderer that a common schedule reduces their risk too. Where the designer does not do this work, commission a separate estimator.