Preliminaries in a BOQ: what they cover, time-related vs fixed
Preliminaries, or prelims, are the project-wide costs of running the job that belong to no single measured item: site management, accommodation, temporary services, plant, insurances and similar. They are priced as fixed charges, which do not change with duration, or time-related charges, which run with the programme.
By BOQ Estimator. Published .
What prelims cover and where they sit
In many building bills the preliminaries come first. Civil engineering bills often call the equivalent section general items, and may include method-related charges where you price the methods you intend to use. The section normally holds the client's requirements and a list of items for you to price.
Prelims depend on the programme, so they are normally priced once the duration, sequence and methods are settled. A longer programme raises the time-related part. The fixed part stays the same. The pricing logic is the one in rate build-up.
The section usually has two kinds of content: text setting out what the client requires, and a list of items for you to price. Read the text before the list. A heading such as site accommodation may carry a requirement for offices, a meeting room or welfare for the client's staff, and the cost sits in the requirement, not in the heading.
Step by step
How to price preliminaries
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Read the client's requirements
They state what must be provided: accommodation, working hours, access, protection, testing and reporting. Price what is required, not what you usually provide.
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Set the programme
Fix the contract duration in weeks and note the phases. Every time-related item multiplies by it.
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Split each item into fixed and time-related parts
A crane has an erect-and-dismantle charge (fixed) and a weekly hire (time-related). Cost the parts separately.
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Cost staff and resources by week
Build supervision by role and time on site. Add hire rates, temporary services and running costs for each week.
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Price value-related items last
Insurances and bonds are often a quoted premium or a percentage of the contract value, so price them once the rest of the tender is known.
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Enter them as the bill asks
Use the unit the bill gives, a lump sum or a weekly rate x weeks. Follow the instructions on blanks and on writing included.
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Sense-check the total
Express it as a percentage of the tender sum and as a cost per week of the programme, and compare both with your own earlier tenders for similar work. A percentage alone can hide a long programme, and a weekly cost alone can hide a large fixed element. Use the comparison as a prompt to look again, not as a rate.
Reference
Typical preliminaries items and how they are priced
| Item | Fixed or time-related | Typical pricing basis |
|---|---|---|
| Site management and supervision | Time-related | Weekly staff cost x weeks on site. |
| Site accommodation and welfare | Both | Delivery, set-up and removal (fixed); hire per week (time-related). |
| Tower crane or hoist | Both | Erect and dismantle (fixed); weekly hire and operator (time-related). |
| Temporary power, water and lighting | Both | Connection charges (fixed); running costs per week (time-related). |
| Scaffolding | Depends | Often measured in the trade section; if in the prelims, erection (fixed) plus hire (time-related). |
| Insurances and bonds | Value-related | Premium quoted for the contract sum, or a percentage. |
| Mobilisation and demobilisation | Fixed | Lump sum. |
| Final cleaning and handover | Fixed | Lump sum. |
Whether an item is fixed or time-related is your costing decision unless the bill dictates it.
Watch for
What goes wrong with preliminaries
- Pricing before the programme is set. Time-related items built on a guessed duration move with every change to it.
- Double counting. Site staff or plant priced in the prelims and again inside the item rates.
- One lump sum for everything. A single figure hides which part moves with time. If a contract later uses your time-related rates to value a change in programme, that matters. The contract sets how.
- Blanks left in the section. A blank may be read as included, as zero or as non-compliant. Follow the tender instructions.
- Ignoring the client's requirements. Working hours, access limits and testing duties all have a cost.
- Programme and preliminaries out of step. For example, a tender programme showing 52 weeks beside preliminaries priced on 48 is a mismatch a reviewer can see. Use one duration in both.
The tool
How BOQ Estimator helps
BOQ Estimator reads the preliminaries section like any other part of the bill. Item numbers stay as printed, units such as sum, item, week and month are recognised, and lines marked as included are tagged so you can find every one. Blank amounts become Quantity x Rate formulas in the Excel workbook, so weekly rate x weeks lines fill in as you price. Try it on the BOQ to Excel converter. Free: 1 file per day, up to 10 pages, no account. Files over 10 pages are converted up to page 10 on the free allowance; a page code converts the whole file, up to 150 pages. See plans and limits.
Related
Related guides
FAQ
Questions estimators ask
What are preliminaries in a bill of quantities?
The part of the bill covering costs that serve the whole project rather than one item of work: management, accommodation, temporary works and services, plant, insurances and similar. They are priced item by item as the bill lists them.
What is the difference between fixed and time-related charges?
A fixed charge is a one-off cost that does not change with the length of the job, such as setting up or removing a facility. A time-related charge runs for as long as the item is needed, such as weekly hire.
Are preliminaries a percentage of the contract value?
Not in the bill, which asks for item prices. Some estimators compare the total with their own past tenders as a sense check. A percentage is a check, not a pricing method.
What are method-related charges?
In civil engineering bills built on CESMM-style rules, charges for the temporary works and methods you choose, split into fixed and time-related parts. Your method statement and programme support them.
What happens to preliminaries if the programme is extended?
Time-related items scale with the duration; fixed items do not. How an extension is valued is set by the contract, so read its terms before assuming.
Where do overheads sit, in the preliminaries or the rates?
Site overheads belong in the preliminaries unless the bill says the rates include them. Head-office overheads and profit are handled as the tender instructions direct. Avoid counting any of them in both places.