Preliminaries

Preliminaries cover everything needed to deliver the work that doesn't belong to one trade package. Typical items include:

• Site staff. Project manager, site manager, foremen, engineers, contract administrators and safety staff.

• Site establishment. Site sheds, amenities, offices, hoarding, fencing and signage.

• Plant and access. Tower cranes, hoists, scaffolding and edge protection used across trades.

• Temporary services. Temporary power, water, lighting and communications.

• Insurances and approvals. Contract works and public liability insurance, permits and authority fees.

• Site running costs. Cleaning, rubbish removal, security, traffic management and surveying.

The exact list depends on the contract and on what has been included in each subcontract package, so read the trade scopes alongside the prelims.

On larger projects the preliminaries budget can be one of the biggest single cost codes on the job, which is why it gets close attention in every monthly cost review.

For a deeper look, read Preliminaries in Construction: What They Are, How to Price Them, and Why They Matter.

Estimators usually split preliminaries into two types.

Fixed or one-off costs happen once regardless of how long the job runs: delivering and erecting the site sheds, crane mobilisation and demobilisation, and initial set-up.

Time-related costs accrue for every week the site is open: supervisors' wages, crane and shed hire, temporary services and security. These are often priced as a weekly or monthly rate multiplied by the programme duration.

Separating the two makes delays easier to price. If the project is extended for a reason the principal is responsible for, time-related preliminaries are usually the main part of the contractor's delay cost claim, subject to the contract's delay costs clause.

Preliminaries are project-specific costs of running this site. Head office overheads, such as the estimating team, accounts and the office lease, are business costs spread across all projects. Margin is the profit on top.

In a tender, prelims are usually priced as their own section of the trade breakdown, separate from both trade costs and the margin. Clients and quantity surveyors often compare prelims between tenderers as a percentage of the contract sum, so unusually high or low prelims attract questions.

On smaller projects, some builders price preliminaries as a single percentage on top of trade costs. That is quick, but it hides the time-related part and makes delay claims and cost reporting harder later. Pricing each item from first principles, even roughly, gives a much clearer basis.

• Underpricing time-related costs. If the programme is optimistic, prelims will run out before the job finishes.

• Gaps and overlaps with trades. Scaffolding, cleaning and crane time are often assumed to be in a trade package when they are not, or priced twice.

• Not tracking prelims burn. Monthly prelims spend should be compared with programme progress, not just the budget.

• Weak delay records. Without dated records of site resources during a delay, prelims claims are hard to support.

Claiming prelims ahead of progress. Front-loading prelims in early progress claims can leave nothing to claim when the late-stage costs arrive.