Preliminaries in Construction: A Guide for UK Contractors

All costs in a construction tender or contract will fall into one of two categories: Those that arise from specific work sections (i.e. direct costs), and those that are a requirement of the project as a whole (i.e. indirect costs). Preliminaries, or "prelims," describe the general conditions for completion of the project that are not tied to specific work sections.

In the UK, the NBS (National Building Specification) produces among the most widely-used standard classification system for preliminaries.

Since construction preliminaries costs impact the entire project, they cover a wide range of materials, equipment and labour. The preliminary might refer to a one-time cost or to an ongoing cost at the project’s start and continuing to close out.

Owners and contractors may wish to account for preliminaries in their contracts because they are often expensive and difficult to apportion across all the project activities. While the owner might specify the items that qualify as preliminaries, it is up to the contractor to claim the amounts required for each item. The contractor is in the best position to estimate these costs.

Common Project Preliminaries

A construction preliminaries list is often extensive and includes costs for items within every aspect of a project. However, there are some common items that are almost always included.

1. Management & Administrative Costs

These costs include payments to project managers, site managers and project stakeholders. Their work is on behalf of the entire project and not just on certain portions. Including those costs in the preliminaries improves transparency for the owner and makes it easier for the contractor to accurately account for the costs.

2. Planning & Design Costs

All construction projects require the contractor to plan the work and create and maintain programmes. It’s impossible to assign this activity to just one work section. The contractor also has added costs for the regular reporting on the programme progress that owners require. As more contracts become collaborative, more contractors are taking on design work to put their expertise in methods and materials to good use. This design work often expands across work sections.

3. Site-Based Services

From access roads to erosion control, construction projects always have elements that improve the site so construction can occur more efficiently and orderly. Projects also have environmental requirements to comply with local and national regulations. Sometimes, construction will impact adjacent structures and neighbours, and so the contractor must account for costs in mitigating damage or annoyance. Therefore, preliminaries in construction also cover these costs.

4. Mockups, Testing & Sampling Costs

Designers and owners often require contractors to supply mockups, showing how finished portions of the project will look once completed. These mockups might be full size, miniature or virtual. Many items in construction must get tested prior to ensure they are fit for the use. Slump testing concrete and randomly sampling moisture content of lumber are two examples.

Construction Preliminaries Examples & Templates

When specifying preliminaries, contracts will often use the NBS numbering system. However, contractors may also use an ad hoc numbering system and text to fit the situation.

Here are two examples of preliminaries from projects in Australia and the UK:

• Griffith University
• World Museum Lighting Installation

A typical construction preliminaries template will include preliminaries for common aspects of a contract, including: 

• 00-05-10 Project Definition 
• 00-05-15 Works Terminology
• 00-05-20 Project Participants 
• 00-05-70 Project Location
• 00-10-70 Works Contract 
• 00-30-70 Works Contract Procurement
• 00-40-70 Works Contract Establishment
• 00-50-70 Works Contract Management
• 00-60-70 Works Contract Verification 
• 00-70-70 Works Contract Administration 
• 00-80-70 Works Contract Completion

Chapter 4

Construction Contract Preliminaries vs. Preambles

The construction preliminaries breakdown and the work sections (work breakdown structure, activities and tasks) should fully describe all that’s required to complete the project.

The preamble names the parties to the contract. It explains the standard for the final product, summarises contract negotiations, explains the tendering procedures, tells the project’s objectives and lists the other documents that make up the total contract. Preliminaries and preambles serve two separate functions of the contract. ​​​

Contractors must be cautious and account for all preliminaries in construction contracts. Overlooking them and their costs can quickly overrun a contractor’s contingency and could lead to disputes.

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