The short answer
Item-rate suits well-defined scope with reliable quantities. EPC or turnkey suits scope where interfaces are the real risk. The deciding question is whether you are better placed than the contractor to carry interface risk.
The contracting model decides where risk sits long before anyone reaches site. Choosing it by habit rather than by scope characteristics is how projects end up in variation disputes.
How the models compare
| Item-rate | EPC / turnkey | |
|---|---|---|
| Best when | Quantities are reliable | Interfaces are the risk |
| Price certainty | Low — quantities move | High — fixed scope |
| Client effort | High — you coordinate | Low — contractor coordinates |
| Variation source | Quantity remeasure | Scope change only |
| Interface risk | Client carries it | Contractor carries it |
The question that decides it
Are you better placed than the contractor to manage the interfaces between civil, structural, mechanical and E&I? With a strong in-house projects team, item-rate can be cheaper. Without one, EPC buys a single point of accountability — usually worth more than the premium.
Where item-rate goes wrong
- BOQ quantities do not match what the drawings actually require
- Nobody owns the gaps between packages, so they become claims
- Each contractor optimises their own scope at the schedule's expense
- The client's team becomes the de facto integrator without the authority
Topics
EPC vs item rateturnkey contract mechanicallump sum contractcontract model selectionvariation claims