When it comes to construction projects, the obvious costs are usually straightforward: bricks, concrete, steel, and labour. But there’s another category of costs that, while less visible, are just as essential — preliminaries, often referred to simply as prelims.
For quantity surveyors, preliminaries represent one of the most important yet frequently misunderstood elements of pricing and valuation. Miss them out, and you risk underpricing, undervaluing, or losing entitlement to legitimate claims. Let’s break them down in detail.
What Are Preliminaries?
Preliminaries are the costs required to set up, manage, and support a construction project — but which don’t form part of the permanent works. In other words, they keep the project running smoothly, but they don’t remain in the finished building.
The Royal Institution of Chartered Surveyors (RICS) defines preliminaries in the New Rules of Measurement (NRM2) as covering:
-
Management and staff
-
Site establishment and accommodation
-
Temporary services (water, electricity, internet)
-
Health, safety, and environmental protection
-
Security and access control
-
Site records and reporting
-
Common user plant and temporary works
-
Completion and post-completion activities (e.g., cleaning, handover documentation)
-
Fees, charges, bonds, guarantees, and insurances
Put simply, preliminaries are the commercial backbone of a project. Without them, the works cannot proceed in a safe, controlled, and compliant way.
Why Are Preliminaries Often Overlooked?
Despite their importance, preliminaries are sometimes under-allowed or ignored altogether. This typically happens in three main stages of a project:
-
Tender Stage – Contractors eager to win work may underestimate preliminaries to make their price appear more competitive. In tight markets, this can be tempting, but it often leads to cash flow problems later on when the real costs become apparent.
-
Valuations Stage – During interim valuations, site preliminaries may be undervalued if they’re not correctly documented, justified, or allocated to work progress. This can affect cash flow and financial reporting accuracy.
-
Claims and Prolongation – When projects overrun, contractors may fail to recover time-related preliminaries because they haven’t clearly demonstrated their entitlement. Lack of records or poorly structured prelim schedules often leads to disputes.
For a QS, understanding and capturing these costs properly is key to protecting commercial outcomes. Recognising preliminaries early and managing them throughout the project lifecycle helps maintain profitability and avoids unnecessary claims.
Fixed vs Time-Related Preliminaries
Preliminaries aren’t always straightforward. Some are fixed costs, such as site signage or insurances, while others are time-related — meaning they accumulate over the project duration.
Examples include:
-
Fixed Preliminaries: Site establishment, initial health and safety documentation, mobilisation costs, insurances, and bonds.
-
Time-Related Preliminaries: Site accommodation, supervision, security, plant hire, and welfare facilities.
This distinction is critical. If a project overruns, time-related preliminaries can grow significantly. A QS must ensure these costs are captured when preparing extension of time (EoT) or prolongation claims.
Under contracts such as JCT and NEC, time-related preliminaries often form a substantial component of delay costs. Demonstrating entitlement requires clear contemporaneous records — site diaries, resource logs, and progress reports — to support the valuation.
How Are Preliminaries Priced and Measured?
In most standard forms of measurement such as NRM2, preliminaries are typically divided into two sections:
-
Main Contractor’s Preliminaries – Covering general items required for the overall management and running of the project.
-
Work Section Preliminaries – Specific items applicable to a particular trade or work package.
Contractors usually price preliminaries as either a lump sum, a percentage of total cost, or broken down into detailed line items. A common mistake is to treat prelims as a fixed percentage (e.g., 10% of project value), which rarely reflects the true requirements of the site.
Instead, effective pricing requires a detailed understanding of the programme, site constraints, and project complexity. For instance, a city-centre refurbishment with limited access will demand higher prelims than a new build on an open site.
For Quantity Surveyors, a well-structured preliminaries breakdown ensures transparency and fair valuation — whether you’re working on behalf of the client or the contractor.
Why Preliminaries Matter
While preliminaries don’t end up in the finished building, they are essential to its successful delivery. They:
-
Ensure compliance with health, safety, and environmental obligations.
-
Provide the facilities and services needed for workers to perform efficiently.
-
Cover the cost of site management, planning, and coordination.
-
Protect the contractor financially when projects extend beyond their planned duration.
-
Form part of the contractor’s entitlement under JCT, NEC, and other forms of contract.
From a client’s perspective, understanding preliminaries helps ensure tenders are evaluated fairly and that cost differences between bidders are properly understood. Two tenders may differ significantly not because of inefficiency, but because one includes realistic preliminaries and the other does not.
Common Pitfalls and Best Practices
Common Pitfalls:
-
Underestimating time-related costs.
-
Poorly defined preliminaries in tender documents.
-
Lack of documentation to support claims.
-
Failure to link preliminaries to programme activities.
Best Practices for QSs and Contractors:
-
Detail Everything Early: Include a comprehensive preliminaries section in tender documentation.
-
Align with Programme: Link prelim costs to project duration and sequence of works.
-
Keep Detailed Records: Maintain daily site logs, resource reports, and evidence of delays.
-
Review Regularly: Reassess preliminaries during progress reviews and valuation cycles.
-
Educate Stakeholders: Help clients and site teams understand the value and necessity of preliminaries.
Good prelim management is not just about cost recovery — it’s about ensuring the project remains organised, compliant, and commercially protected.
Final Thoughts
Preliminaries may sit behind the scenes, but they are the unsung heroes of construction project delivery. For Quantity Surveyors, a deep understanding of preliminaries — their scope, valuation, and time-related nature — is vital. Whether at tender stage, during valuations, or when preparing claims, recognising and managing preliminaries correctly protects the bottom line and builds commercial credibility.
At Gray Quantity Surveyors, we support developers, contractors, and subcontractors in ensuring preliminaries are accurately priced, properly managed, and fully recoverable. From tender preparation through to final accounts and claims, our team ensures no cost is left behind.
Efficiency. Professionalism. Excellence.