Case 04

Omission / Substitution

Omission
Substitution
Option B

The commercial question

“Can the QS simply deduct the original BoQ value and add the replacement quotation?”

Illustrative scenarios

These are independently created fictional scenarios for professional learning. Figures and conclusions are illustrative, not project-specific assessments or standard rates.

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Project scenario

NEC4 ECC Option B

Original Scope: 40 precast equipment bases. Original Bill of Quantities value: £80,000.

The PM changes the Scope. The original bases are replaced by 32 larger reinforced in-situ bases requiring reinforcement, formwork, changed lifting arrangements and a revised sequence.

Contractor position

The Contractor submits a net change of:

+£38,000

Net submission before Fee

Contractor submission
Omit original work	−£80,000
Replacement work	+£112,000
Additional supervision	+£6,000
Net submission before Fee	+£38,000

What would you challenge first?

The original BoQ value is not automatically the Defined Cost of the omitted work.
The replacement quotation is not automatically the CE valuation.
Not every original cost necessarily disappears when work is omitted.
Additional supervision still requires a demonstrated cost effect.

Key commercial principle

“The tender tells you what was priced. The CE assessment asks what Defined Cost changed because of the event.”

“For a substitution, review both sides of the change — what would have happened without the CE and what is forecast to happen with it.”

Option B clarification: For Option B, the Defined Cost assessment feeds into the contractual adjustment of the Bill of Quantities / Prices. The assessment is not simply replacement quotation minus original BoQ value, and the conceptual Without-CE / With-CE comparison should not be presented as the entire Option B payment mechanism.

Existing commitments: Existing commitments such as ordered materials, incurred design, booked plant, cancellation charges, reuse or supplier credits may affect what cost was actually avoided or remains forecast because of the CE, subject to the applicable Defined Cost rules.

Commercial Desk headline diagnosis

Assessment basis requires further review.

One Compensation Event may create multiple effects — direct changed work, labour and resource effects, plant, disruption, resequencing, temporary works, programme delay and prolongation. Those effects are not automatically separate Compensation Events.

How the conceptual comparison works

Without CE

Raw resource / cost position → Applicable SCC / SSCC rules → Without-CE Defined Cost

With CE

Raw resource / cost position → Applicable SCC / SSCC rules → With-CE Defined Cost

Identify the CE-caused Defined Cost effect, then apply the applicable Fee treatment.

See the Worked Commercial Solution

Full Worked Solution

Part of the upcoming NEC4 Compensation Events Pack.

The Pack includes:

Cases 01–06 full Worked Solutions
Main Option A–F impact analysis (not six recalculated versions of each Case)
Advanced Option B/D Quantity-change Module where applicable
Structured evidence and commercial assessment guidance
Example response wording

Planned launch price: £79 one-off. No subscription. Coming soon.

Based on the standard NEC4 ECC framework. Always check the applicable Contract Data, secondary Options, Y clauses, Z clauses, local amendments and governing law before applying the worked examples to a live contract.

Related Commercial Desk tools

Quotation Review

Check whether a CE quotation looks commercially complete.

Open Quotation Review

Commercial Desk is an independent practical reference for construction professionals. It is not affiliated with or endorsed by NEC. It does not reproduce the NEC4 contract and is not a substitute for the applicable executed contract or professional or legal advice. Always check the relevant contract, Contract Data and amendments.