Preliminaries

Preliminaries are the project-wide requirements and costs of making the construction work possible on a particular site. A tender prices concrete, walls and finishes, but it also needs a site office, supervision and temporary power to organise that work, and those items may sit in a preliminaries section.

Designing Buildings describes preliminaries as tender requirements and costs linked to the method and circumstances of the works rather than to one package of permanent building work, and scope varies by project. RICS New Rules of Measurement provide guidance for consistent construction cost measurement, and their schedules can help bidders set out preliminaries, though a client's particular tender documents still govern what bidders must include.

A fictional contractor prices site fencing, welfare facilities and a supervisor under preliminaries, and bricks and labour to build walls under the building work. Clear separation helps compare tender submissions.

Some preliminaries are one-off, such as initial site setup, while others depend on duration, such as monthly security or office hire, so label the basis because a delayed project affects them differently. A fictional site has a six-month programme and a supervisor costing $8,000 per month, and if work lasts longer the actual time-related cost can grow, although the right contractual recovery is a separate question.

A listed preliminary does not automatically become an extra payment when the programme changes, because notice, causation, mitigation and valuation rules in the contract matter, so avoid multiplying every monthly item by every extra month without review. Preliminaries can include site safety, environmental protection, common-use plant and cleaning, while some specialist subcontractor costs may instead be embedded in trade rates, so do not double count them.

A fictional builder that hires a crane shared by several trades must decide whether the common-use item sits in preliminaries or within trade prices, and the tender should make the choice clear. A client comparing bids may see one bidder with low preliminaries and higher trade rates, so compare total scope and assumptions rather than a percentage alone.

The ratio of preliminaries to tender price can be useful context but is not a universal benchmark, because project duration, access constraints, logistics and reporting duties change it, and a fixed 8% to 15% rule should not be applied to every tender. A fictional hospital refurbishment that works around live services and patients has different site-management costs from a vacant new-build plot, and the difference can be real rather than an inflated bid.

Preliminaries may also describe non-price requirements, such as programme reporting or approval procedures, which the contractor needs to cost, because a scope omission can become a dispute later. Site overheads are a related cost term, and a company-wide head-office overhead may be treated separately, so identify the particular project costs before comparing them.

A tenderer should read the employer's conditions and estimate actual resources such as staff, site facilities and time, because a guessed percentage can conceal missing items, as a fictional contractor found when its low site-security allowance met a tender that required overnight coverage. When variations occur, check whether they change project-wide requirements, ask bidders to separate fixed and time-related preliminaries, and document what each price includes, since insurance, temporary works and utility charges can overlap with other schedules.