How to compare contractor quotations fairly
Three quotations with three different totals are usually three different scopes. Normalising them is the actual work.
A spread of quotations rarely means one contractor is cheaper. More often it means they have priced different things, and the comparison as received is meaningless.
Normalise the scope first
Before comparing any numbers, list what each quotation includes and where they differ. Common divergences:
- Access equipment included or excluded
- Surface preparation and coating standard
- Testing, inspection and documentation
- Temporary works and its design
- Making good, cleaning and waste removal
- Out-of-hours or restricted working allowances
Look at the assumptions
Most quotations carry a list of assumptions, and they are where risk has been placed. "Assumes continuous crane access" means any interruption becomes a variation. The lowest quotation is often the one that has assumed the most.
Ask about programme, not just price
A price that depends on a programme nobody has checked is a provisional price. Ask how long the work takes, what it depends on, and what happens if a prerequisite is late.
Check the resourcing
Who is actually doing the work, how many of them, and whether any of it is subcontracted. This is not an intrusive question; it is the difference between a quotation and a guess.
The red flag
A quotation substantially below the others, with a short scope and a long assumptions list. It is not a bargain, it is a different job — and the gap usually reappears as variations once work has started and switching is no longer practical.