What is a deviation in a construction contract (extra item, substituted item)?
A deviation is a change in the quantity of an item that is already in the contract, and the contract's deviation limit decides how much of that change is paid at the agreed rate; an extra item is new work with no line in the contract, and a substituted item replaces an agreed item.
Also called deviation in quantity, extra item, substituted item, deviation statement.
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Deviation in plain words
Indian public works contracts, such as those on CPWD-style conditions, treat the three differently. Quantities within the deviation limit are paid at the contract rate. Quantities beyond it, extra items and substituted items need a rate worked out and approved, often from a rate analysis, before they can be billed in full. A deviation statement records the changed quantities against the BOQ.
What is the difference between a deviation, an extra item and a substituted item?
A deviation changes the quantity of an existing item; an extra item adds work the contract never listed; a substituted item takes the place of a listed item.
| Deviation | Extra item | Substituted item | |
|---|---|---|---|
| Is the item in the BOQ? | Yes | No | It replaces one that is |
| What changes | The quantity | New work is added | The item or its specification |
| Rate | Contract rate within the deviation limit; a new rate beyond it, as the contract sets | Worked out and approved | Worked out from the agreed item, as the contract sets |
General Indian public works practice, not a quoted clause. The deviation limit and the pricing rules come from your contract's own deviation clause.
Why does deviation matter?
Work beyond the deviation limit, extra items and substituted items cannot be paid in full until a rate is approved, so the cost is incurred while the cash waits for the rate.
Where does deviation mislead?
The deviation limit, what counts as an extra or a substituted item and how each is priced differ between contracts and between versions of the same standard conditions. Check your contract's deviation clause; a limit quoted from another contract does not apply to your work.
What do people get wrong about deviation?
- Executing beyond the limit before approval
- Where the contract requires approval for quantities beyond the limit, work done first and approved later becomes a claim rather than a bill.