Prelims in construction, short for preliminaries, are the costs of running a building job that don't belong to any one piece of work. The Chartered Institute of Building's estimating code, quoted by Designing Buildings, describes them as the cost of administering a project and providing general plant, site staff and facilities. On a house or shop refurbishment that means the person supervising, the floor protection, the skip, somewhere for the trades to wash and eat, and setting the job out.
What do prelims include?
Prelims include supervision, site set-up and welfare, protection, waste, access equipment and setting out.
| Item | On a small refurbishment |
|---|---|
| Management and supervision | A working supervisor or site manager, and the time spent ordering and coordinating |
| Site set-up and welfare | Toilet, washing and rest arrangements, and power and water for the works |
| Protection | Floor and stair coverings, dust screens, and protection to lifts and shared hallways |
| Waste | Skips or waste collections, and any permit they need |
| Access and plant | Towers, podiums and scaffolding where no single trade carries them |
| Setting out | Marking the work out before each stage |
What do prelims look like on a real quote?
On a labour-only drylining tender we priced, the prelims line was a lump sum for "one working supervisor, one labourer for approximately six weeks", with normal tools and moving materials at the workface. The same tender said access equipment and hired plant would be provided by the main contractor, and that our price did not include "main-contractor preliminaries".
On a job with a main contractor it often splits that way. Each trade prices its own supervision and tools, and the main contractor carries shared items such as welfare, skips and access. On a house refurbishment with one builder, all of it sits in that builder's prelims.
On two other refurbishment quotations our director prepared, prelims were grouped with other early items: with protection, strip-out and waste on one, and with protection and setting out on the other. Grouping is common on small jobs. It also makes two quotes hard to compare, because one builder's prelims line contains the strip-out and another's does not. Sending every builder the same schedule of works avoids that.
Why are prelims a separate line?
They depend on time more than on quantity. Tiling twice the area costs about twice as much. Supervising a job for twice as long also costs twice as much, even if nothing is added to the work. So when a job runs longer because of late decisions or extra work, prelims grow with it. A quote that shows them separately lets you see that cost in advance.
What should you check in the prelims line?
- How many weeks does it assume, and what happens to the figure if the job runs longer?
- Is skip hire, scaffolding or a parking suspension in it, or priced elsewhere?
- Who protects shared areas such as hallways and lifts, and who cleans them?
- Is there a named person on site each day?
- If the line is a percentage, what is it a percentage of?
- Is the final clean in the prelims or in a handover line? It should appear once.
If you would like a quotation where prelims are listed as their own items with the weeks they assume, say so when you send the drawings and the postcode. We reply within one working day. Ask for a quotation with prelims listed.