Acceleration and constructive acceleration

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Legal and contractual solutions · Loss and expense

When may a contractor recover acceleration costs, and what is constructive acceleration?

Instruction, agreement, breach and proof of incremental cost

Acceleration cost is recoverable where the contract or an agreement provides for it, or where proven employer's breach causes the contractor reasonably to incur acceleration expenditure. Constructive acceleration is not an automatic label for every refusal of an extension.

Quick answer

Recoverability depends on contractual authority, agreement or a proved breach causing reasonable acceleration cost

If the contractor is behind through its own risk, it may be required to recover progress under the contract without additional payment. Bringing forward completion or overcoming employer-risk delay usually requires an express mechanism or agreement. A constructive-acceleration case may arise where the contractor is entitled to time, gives the required notice, the extension is wrongly withheld or delayed, the employer still requires the unadjusted date, and reasonable additional resources are incurred. Each element and the causal cost must be proved.

IssuePosition
Contractor-risk recoveryUsually contractor cost unless the contract says otherwise
Agreed accelerationDefine measures, date, price and risk allocation
Employer-risk delayExtension and cost routes apply
Constructive accelerationPotential breach-damages analysis, not automatic entitlement
QuantumCompare no-acceleration resources with actual measures
Section 1

Separate recovery from acceleration

Recovery measures restore progress lost through contractor-risk events. Acceleration changes the planned rate or sequence to achieve an earlier result or overcome excusable delay. The same additional labour may appear in both, but entitlement differs.

Section 2

Express instructed acceleration

A contract may empower a decision-maker to request a quotation, instruct measures or agree an earlier date. Apply the required proposal, acceptance, programme and valuation process before committing substantial cost.

Agree the bargain before spending

Record the target date, measures, assumptions, price, effect on extensions, productivity risk and consequences if the target is not achieved.

Section 3

Contractor-risk delay

Where progress is insufficient because of contractor's default, the contract may require additional resources to meet the existing completion date without payment. The contractor may compare recovery cost with delay-damages exposure, subject to its continuing performance obligations.

Section 4

Employer-requested earlier completion

Bringing the date forward is a variation of risk and price unless an existing clause supplies the mechanism. Contractor agreement is ordinarily required where the contract does not confer a unilateral power.

Section 5

What constructive acceleration describes

The expression describes a breach-damages case in which the contractor is contractually entitled to time, but the employer fails to recognise it while insisting on the unchanged date, causing reasonable acceleration expenditure. The legal basis remains the contract and proved breach.

Section 6

Overseas authorities

Perini Corporation v Commonwealth of Australia(1969) 12 BLR 82

Constructive acceleration required a proved owner's breach and proof of additional expenditure incurred to complete on time.

Morrison-Knudsen Co Inc v British Columbia Hydro and Power Authority(1978) 85 DLR (3d) 186

Extensions were deliberately refused, and damages were measured by the additional expense of accelerated completion.

W Stephenson (Western) Ltd v Metro Canada Ltd(1987) 27 CLR 113 (BCSC)

Damages were awarded where the employer stated that no extension would be granted and acceleration followed.

Section 7

Motherwell Bridge

Motherwell Bridge Construction Ltd v Micafil Vakuumtechnik(2002) 81 Con LR 44

There was additional welding, an entitlement to more time, and a failure to grant it. The subcontractor recovered acceleration cost incurred in attempting to meet the original date.

Section 8

Entitlement evidence

ElementEvidence
Excusable delayEvent and extension entitlement under the contract.
NoticeCompliant notice, particulars and extension application.
Decision failureRefusal, under-award or unreasonable failure to decide.
Completion demandEvidence that the unchanged date remained required.
Reasonable responseWhy acceleration was selected and alternatives considered.
ReservationContemporaneous statement that cost and time rights were maintained.
Section 9

Quantum evidence

ElementEvidence
No-acceleration planResources and completion date with the extension due.
Acceleration planExtra shifts, labour, plant, supervision and resequencing.
Actual recordsHours, cost, productivity and dates by activity.
InefficiencyCongestion, fatigue, stacking and out-of-sequence effect.
SavingsShorter duration, avoided preliminaries and reduced damages.
Other causesRemove contractor recovery and unrelated disruption.
Section 10

Acceleration versus disruption

Acceleration cost includes additional resources and productivity loss caused by their deployment. Disruption may arise without an acceleration objective. Keep the causal narratives and valuation methods separate, then remove overlapping labour or inefficiency.

Section 11

Practical sequence

1

Identify the current completion obligation and delay responsibility.

2

Secure an acceleration instruction or written agreement where possible.

3

If time is withheld, preserve the extension application and completion demand.

4

Prepare no-acceleration and acceleration resource plans.

5

Record resources, shifts and productivity by activity.

6

Quantify incremental cost and all savings.

7

Separate acceleration, recovery and disruption claims.

Section 12

Authorities

AuthorityYearWhat it decides
Perini Corporation v Commonwealth of Australia(1969) 12 BLR 82Proved breach and additional acceleration expenditure were required.
Morrison-Knudsen Co Inc v British Columbia Hydro and Power Authority(1978) 85 DLR (3d) 186Deliberate extension refusal supported the recorded acceleration damages.
W Stephenson (Western) Ltd v Metro Canada Ltd(1987) 27 CLR 113 (BCSC)A refusal to grant any extension supported the recorded damages claim.
Motherwell Bridge Construction Ltd v Micafil Vakuumtechnik(2002) 81 Con LR 44Acceleration cost followed failure to grant time due for added work.
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Note
This page states the position on the authorities listed as at 13 July 2026. Enforceability depends on the clause, contractual setting, facts and applicable law. This material is provided for educational and professional development purposes only and does not constitute legal advice. Always consult qualified professionals before acting. SCCSI and its contributors accept no liability for reliance on this material.