Prelims. Preliminaries. General Site Costs. Whatever you call them — most UK builders either forget them entirely or shove a vague number in at the end.
This is one of the most common — and costly — mistakes we see when reviewing builder quotes.
What Proper Prelims Should Include
- 📋 Site management & supervision
- 📋 Temporary works (hoarding, scaffolding hire)
- 📋 Site welfare (toilets, welfare cabin)
- 📋 Plant & equipment hire
- 📋 Skip hire & waste removal
- 📋 Insurance & bonds
- 📋 Health & safety compliance
- 📋 Drawings & planning costs
- 📋 Travel & accommodation (where applicable)
What Prelims Should Cost on a Typical UK Job
On a typical £100k residential extension, prelims should be £8,000–£15,000.
Most builders price them at £2,000 — or nothing at all.
That’s £6,000–£13,000 of YOUR money that you’re gifting to the client every single job.
Over 10 jobs a year, that’s potentially £130,000 in lost margin.
Why Builders Underprice Prelims
It’s not laziness. It’s because properly costing prelims takes time, knowledge, and a systematic approach that most busy builders simply don’t have.
That’s exactly what a QS service is for.
Every RapidQS report includes a fully itemised prelims section. Not a guess. Not a percentage. An actual breakdown of every cost you’ll incur before a single brick is laid.
This is how you protect your margin on every job — and stop working for free.
→ Next job coming up? Send your plans to david@rapidqs.com — report back in 48 hours
