Extension of Time in Construction Contracts in Vietnam: FIDIC and Decree 210

Updated: 22 October 2026 · IVLF Advisors

When a project runs late, the contractor needs a new completion date and the employer needs to know whether delay damages are running. The answer depends on whether a valid claim was made in time. Handling an extension of time construction contract Vietnam claim well protects the contractor against delay damages and protects the employer against an open-ended programme and a lender default.

Vietnamese law leaves most of the mechanics to the contract, while FIDIC 1999 imposes a strict 28-day notice, so the drafting of this one clause often decides who pays. The point matters most on large projects, from expressway and airport-terminal packages to factories, solar farms and resort complexes, where one late milestone can ripple through many interfaces.

Extension of time in Vietnamese law: what the statute says and leaves open

Decree 210/2026/NĐ-CP (Decree 210), effective 1 July 2026, defines the time architecture of a construction contract in Article 10. The contract validity period runs from effectiveness until all obligations, including additional work and liquidation, are complete or the contract ends. The time for performing the work runs from effectiveness or commencement until completion and acceptance, includes any extension, and excludes warranty, author supervision and liquidation. For public investment, it is the package time under procurement law.

Article 25(1) is the core rule. The parties themselves agree the cases in which time, schedule or completion date may be adjusted, and who is responsible for loss caused by a prolongation. The law does not provide a list of entitlement events or a notice deadline. Article 84(2) of the Construction Law No. 135/2025/QH15 supplies the broad grounds on which the parties may agree an amendment, and these include a change of policy or law, force majeure, fundamental change of circumstances and changes of scope or schedule.

In practice, the extension of time construction contract Vietnam rules are therefore contractual. A contract that is silent on entitlement, notice and evidence invites argument. For public-investment and PPP projects, Article 25(2) adds an approval step: if an adjustment would take the contract beyond the approved project duration, the investor must report to the decision-maker and obtain a decision before the parties agree the new contract schedule.

Delay events and who bears the risk

An extension of time is the contractor’s remedy for delay for which it should not bear the consequences. The table summarises the main events and how they are normally treated. FIDIC references are to the 1999 Silver Book; the Vietnamese references show where the law supports an amendment.

Delay event	FIDIC 1999 (Silver Book)	Vietnamese hook
Employer variation	8.4(a): extension, unless time agreed under 13.3	Amendment of scope or schedule (Construction Law Art 84(2))
Late site access	2.1: extension and cost plus profit, subject to 20.1	Agreed in contract; site handover record is key evidence
Authority delay	8.5: if the contractor followed procedures diligently and delay was not foreseeable at tender	Contract; regulatory approvals are a common Vietnam risk
Employer suspension	8.9: extension and cost, unless the cause is the contractor’s	Suspension rules (Construction Law Art 85)
Change in law	13.7: after the Base Date	Art 84(2)(a); Art 13(2)(a)
Force majeure	19.4: extension; cost only for some categories	Art 13(1) and Civil Code Art 156
Unforeseen ground conditions	4.12: contractor bears the risk unless the contract says otherwise	Possible fundamental change: Art 13(2)(b) and Civil Code Art 420
Contractor’s own delay	No extension; 8.6 may require a recovery programme	Responsibility under the contract

The last two rows show why the allocation of risk must be decided before signature. An EPC contractor under the Silver Book carries ground risk in principle, so a Vietnamese employer should not assume that an unforeseen geological condition will automatically justify an extension. Conversely, if the contract is silent, Article 13(2)(b) of the Construction Law at least gives the parties a statutory category for abnormal geological conditions.

Extension of time construction contract Vietnam: FIDIC Sub-Clause 8.4 explained

Extension of time construction contract Vietnam: the grounds in Sub-Clause 8.4

Sub-Clause 8.4 of the FIDIC 1999 Silver Book gives the Contractor an extension, subject to Sub-Clause 20.1, if and to the extent that completion is or will be delayed by one of three causes: a Variation, a cause of delay that gives an entitlement under another Sub-Clause, or delay, impediment or prevention caused by or attributable to the Employer, its personnel or its other contractors on Site. Two words matter: “if and to the extent”. An extension is proportionate to the actual effect on completion, not to the length of the event.

Notice, claim and determination

The procedure is in Sub-Clause 20.1 and is demanding:

• notice as soon as practicable, and no later than 28 days after the Contractor became aware, or should have become aware, of the event;
• failing that notice, the Time for Completion is not extended and the Employer is discharged from liability for the claim;
• a fully detailed claim within 42 days, then monthly interim claims and a final claim within 28 days after the effects end;
• a response from the Employer within 42 days, approving or giving detailed reasons for disapproval; and
• contemporaneous records kept by the Contractor throughout.

Under Sub-Clause 8.4, when determining each extension the Employer reviews previous determinations and may increase, but not decrease, the total extension. In the Red and Yellow Books it is the Engineer who makes the determination, which makes that person’s role central; we discuss it in our article on the Engineer role under FIDIC contracts in Vietnam.

A practical caution applies. Whether a strict contractual bar of this kind will be enforced in full under Vietnamese law, as the governing law, depends on the contract wording and the facts. Contractors should treat the 28 days as binding. Employers should not assume that late notice will always defeat a claim.

Site access, mitigation and acceleration

The most frequent employer-side cause of delay is late access to the site. Article 12(3)(a) of Decree 210 shows the legal sensitivity: in public-investment and PPP contracts, an advance payment for construction work requires a site clearance plan or a record of handover of the site, in whole or in part.

Sub-Clause 2.1 of the Silver Book requires access within the time stated in the Particular Conditions, or from the Commencement Date if none is stated, although the Employer may withhold access until it receives the Performance Security. A signed handover record, with dates and areas, is the best single document in a later claim.

Mitigation matters as much as entitlement. If progress falls behind for reasons that do not entitle the Contractor to an extension, Sub-Clause 8.6 allows the Employer to instruct a revised programme, and the Contractor adopts the revised methods at its own risk and cost.

By contrast, an Employer instruction to finish earlier than the extended date is, as a matter of market practice, usually treated as a variation to be priced. Under Article 18(4) of Decree 210, a party that cannot perform because of force majeure or fundamental change must give written notice and propose a solution, which in practice means a recovery plan.

Programme, critical path and delay analysis: proving the extension

A claim for time is a claim about the critical path. The contractor must show that the event delayed completion, not merely some activity. Sub-Clause 8.3 therefore requires an initial programme within 28 days of the Commencement Date and a revised programme whenever progress departs from it, and it requires the Contractor to give prompt notice of events likely to cause delay.

A sound delay analysis usually involves four steps, which reflect market practice rather than any Vietnamese rule:

1. fix an accepted baseline programme and update it regularly;
2. identify each claimed event and the activities it affected;
3. test the effect on the critical path and on float, using the method the contract allows; and
4. keep records (site diaries, letters, photographs, resource histograms) that show the facts at the time.

The Society of Construction Law Delay and Disruption Protocol, an English-law guidance document that is widely referred to in international projects, recommends that accurate analysis of float and concurrency depends on a properly updated programme. Its guidance is persuasive rather than binding, and a Vietnamese court is not required to follow it, but arbitral tribunals in international cases often find it useful.

Concurrent delay: how an extension of time is affected

Concurrent delay arises when an employer-risk event and a contractor-risk event affect completion in the same period. Vietnamese law has no specific rule, so the result depends on the contract and on general principles of good faith and causation.

The SCL Protocol, again as English-law market guidance, recommends that where contractor delay occurs concurrently with employer delay, the contractor’s concurrent delay should not reduce the extension of time. For money, its approach is stricter: prolongation costs are recoverable only to the extent they can be separated from those caused by the contractor’s delay. The first rule reflects what lawyers call the prevention principle: an employer should not take advantage of its own breach by imposing damages for the period it caused.

For your contract, the lesson is to decide in advance. A well-drafted concurrent delay clause states whether the contractor receives time only, time and cost, or neither, and how concurrency is proved. Silence leaves the allocation to the tribunal.

A hypothetical example

This hypothetical is for illustration only. An EPC contract has a 24-month Time for Completion. The employer hands over part of the site ten weeks late. Separately, the contractor’s piling subcontractor underperforms for six weeks, and four of those weeks overlap the late handover. If the contract is silent on concurrency, the parties will argue about whether the extension is ten weeks, six weeks or something in between. A clause that states the rule, together with an updated programme, converts that argument into arithmetic. This is the practical value of a clear extension of time construction contract Vietnam clause.

Extension of time and delay damages: why the completion date matters

An extension moves the Time for Completion. Under Sub-Clause 8.7 of the Silver Book, delay damages run for every day between the relevant Time for Completion and the date in the Taking-Over Certificate, up to a maximum stated in the Particular Conditions. If the extension is refused or never claimed, damages run from the original date. If it is granted, they run from the new one. Termination exposure under Sub-Clause 15.2 also depends on whether the contractor has failed to proceed with the Works without reasonable excuse.

For Vietnamese projects, that interplay is one reason to read the time clause together with the damages clause. We examine the cap, enforceability and the 12% rule for public-investment and PPP contracts in our article on delay damages and liquidated damages in Vietnam.

Approvals and funding constraints in public-investment and PPP projects

Where the project is public-investment or PPP, a time extension may have consequences beyond the contract. Article 84(3) of the Construction Law lets the investor decide an amendment that changes contract duration within the approved project duration. If the new date exceeds the approved duration, Article 25(2) of Decree 210 requires the investor to obtain a decision from the decision-maker first. For lenders and sponsors, this means that a mutual agreement between site teams on a new date may be ineffective until the approval is in hand, and the long-stop date in the financing documents may need a parallel amendment.

Drafting checklist for an extension of time clause

• Employers: list entitlement events precisely, set notice and particulars deadlines, and require an updated programme with every claim.
• Contractors: diarise the 28-day notice, send notice even if the effect is uncertain, and keep a programme that a tribunal can follow.
• Lenders: align the completion date in the construction contract with the financing long-stop date, and require notice of every claim.
• All parties: agree how concurrent delay is treated and who determines the extension.
• Foreign sponsors: ask local counsel whether site-level instructions, emails and meeting minutes are enough to bind a state-linked employer, and require formal written approval for every extension.
• Everyone: keep a single claims register that shows the event, the notice date, the programme revision and the status of each determination, so that the record can be produced quickly in any later negotiation or arbitration.

Extension of time construction contract Vietnam across project types: infrastructure, industry, energy and real estate

The Sub-Clause 8.4 mechanics are the same on every site, but the events that cause delay, and the approvals needed to grant time, differ sharply by sector. The examples below are hypothetical and illustrate typical patterns only.

Infrastructure and transport

Expressways, ports, metro lines, rail stations and airport terminals are often State-funded or State-owned, so they often fall within the public-investment or PPP regime, although classification depends on the funding source and is determined project by project. Delay events here are frequently land handover, utility relocation and interface with other packages.

On a very large programme such as the planned North–South high-speed railway (about 1,541 km between Hanoi and Ho Chi Minh City, through 15 provinces and cities, with a design speed of 350 km/h), time-related decisions would typically pass through several approval layers; the Decree 210 approval step noted above is then a real critical-path item.

For an airport terminal such as phase 1 of Long Thành International Airport, whose commercial operation is expected from 24 December 2026 according to press reports, the fixed opening date shows why systems-integration packages need their own time-claim discipline.

Heavy industry and factories

Steel, petrochemical and cement plants and FDI factories in industrial parks are usually privately funded and turnkey, so the contract rather than Decree 210 sets the rules. Delays tend to come from imported equipment, commissioning and performance testing. A hypothetical lender-backed plant will usually need an extension that matches the loan availability period.

Renewable energy and power

For a solar farm, wind project or gas-to-power plant, the controlling date is often a deadline in a power purchase or connection arrangement. Grid-connection delay by a third party is a classic cause of lost time; whether it counts as an Employer risk event depends on the drafting. Ownership and offtake structures are fact-specific, and the applicable electricity-law regime should be checked.

Real estate: resorts, hotels, urban areas and mixed-use

Resort, hotel and mixed-use developments (retail, hospitality and residential) are normally private, so party agreement governs. Fit-out, design changes by operators and phased handover to buyers make rolling extensions common. Sales and handover commitments to end buyers can make the completion date more valuable than the contract price suggests.

Sector	Typical time-claim feature	What to check
Expressway, rail, airport terminal	Land handover, utility and interface delay; layered approvals	Whether Decree 210 Article 25(2) applies; approval lead time
Factory, steel, cement	Equipment import, commissioning	Test-completion definition; lender dates
Solar, wind, gas-to-power	Grid connection, permits, offtake deadline	Third-party delay as Employer risk; long-stop dates
Resort, hotel, mixed-use	Design changes, phased handover	Notice routes; buyer-handover exposure

Conclusion

Time claims are decided by notices, programmes and records, not by argument at the end. As a next step, compare the time clause in your contract against Sub-Clause 8.4 and Sub-Clause 20.1, and check that any approval needed under Decree 210 Article 25(2) is built into the process.

For further reading, the FIDIC website describes the contract forms, and the text of the 2025 Construction Law is available online.

Frequently Asked Questions

Is there a statutory time limit to claim an extension in Vietnam?

Decree 210 Article 25 leaves the cases and procedure to the contract. A FIDIC-based contract will normally impose its own 28-day notice, so check the contract first.

What happens if I miss the 28-day notice under FIDIC?

Under Sub-Clause 20.1 of the 1999 edition, the Time for Completion is not extended and the Employer is discharged from the claim. Enforceability under Vietnamese law should be checked on the facts.

Does concurrent delay reduce my extension?

Vietnamese law has no specific rule. The SCL Protocol recommends that concurrent contractor delay should not reduce the extension, but the contract can provide otherwise.

Can the employer reduce an extension already granted?

Under Sub-Clause 8.4, when determining each extension the Employer may increase but not decrease the total extension previously determined.

Do public projects need approval for a longer duration?

Yes. For public-investment and PPP projects, an extension beyond the approved project duration needs the investor to obtain a decision from the decision-maker first.

Disclaimer: This article provides general information only and is not legal advice for any specific matter. It reflects Vietnamese law as of 22 October 2026. Please obtain advice on your own facts before acting.