The Engineer Role under FIDIC in Vietnam: Powers, Limits and Local Law

Updated: 22 October 2026 · IVLF Advisors

Many disputes on Vietnam projects begin with a misunderstanding about who the “Engineer” is and what that person can bind. The Engineer role FIDIC construction Vietnam projects rely on is not the same as the Vietnamese supervision consultant, and mixing the two can leave certificates unsigned, instructions unauthorised and payments contested.

This article explains the Engineer’s powers and limits under the FIDIC 1999 edition, how the Silver Book differs, and how the role fits with Vietnamese law on supervision, acceptance and payment. How the role is staffed also varies by sector, from State-owned airport and expressway owners to private factory, energy and resort developers.

Engineer, Employer’s Representative and supervision consultant: three different roles

Three labels appear on Vietnamese projects, and they do not mean the same thing.

• The Engineer is a contractual role in the FIDIC Red Book and Yellow Book. It is appointed by the Employer, is named in the contract, and carries the powers that the contract gives it (instructions, certificates, determinations).
• The Employer’s Representative is the Silver Book equivalent, but with a significant difference. It is an optional agent of the Employer rather than a quasi-independent certifier.
• The supervision consultant (tư vấn giám sát) is a statutory construction role under Vietnamese law. It supervises the construction works on the owner’s behalf, within the statutory framework.

A single firm can perform more than one role, and in practice often does. But the legal source and consequences of each differ, so the contract should say expressly who performs which function.

The Engineer role FIDIC construction Vietnam contracts rely on

The following refers to the FIDIC 1999 edition. We have reviewed the Silver Book text in full and the Vietnamese translation of the Red Book in the Multilateral Development Bank Harmonised Edition (2010); where a point relies on the harmonised text, we say so. The 2017 second edition is not analysed here.

Appointment, staff and delegation

Under Sub-Clause 3.1 of the Red Book text, the Employer appoints the Engineer to carry out the duties assigned in the Contract, and the Engineer’s staff must include suitably qualified engineers and professionals competent to perform those duties. The Engineer has no authority to amend the Contract, and may exercise only the authority stated in or necessarily implied by the Contract.

Sub-Clause 3.2 lets the Engineer delegate to assistants, such as a resident engineer or independent inspectors. Delegation takes effect only once both parties receive a copy in writing. In the harmonised text, matters under Sub-Clause 3.5 may not be delegated unless the parties agree otherwise. An assistant’s act within the delegation has the same effect as the Engineer’s own.

Engineer role FIDIC construction Vietnam: acting for the Employer, with a duty to be fair

The most misunderstood feature of the Engineer role is its dual character. When carrying out duties or exercising authority, the Engineer is treated as acting for the Employer, so the Contractor cannot treat the Engineer as a neutral arbitrator in general. Equally, the Engineer cannot relieve either party of duties and cannot, through approval or silence, relieve the Contractor of its responsibilities.

However, where the contract says the Engineer is to agree or determine a matter under Sub-Clause 3.5, a different standard applies. The Engineer must consult each party in an endeavour to reach agreement, and, failing agreement, make a fair determination in accordance with the Contract, taking due regard of all relevant circumstances.

In the harmonised text, the Engineer must give notice of each agreement or determination to both parties, with supporting particulars, within 28 days of receiving the claim or request unless otherwise stated. Each party must give effect to the determination unless and until it is revised under the dispute provisions.

So the Engineer is an agent for most purposes, and an impartial decision-maker for determinations. That duality is the source of much of the friction in practice, particularly where the Engineer is employed by, or dependent on, the Employer for other work.

Limits on authority in the harmonised text

In the harmonised edition used on many development-bank-financed projects, the Engineer must obtain the Employer’s specific approval before taking certain actions, including agreeing or determining an extension of time or additional cost under Sub-Clause 4.12 and instructing a Variation (with exceptions for emergencies and for Variations below a percentage stated in the Contract Data). Where the Engineer exercises an authority that requires that approval, the Employer is deemed to have approved. Those limits must be disclosed in the Particular Conditions.

Market practice on privately financed projects is to impose similar limits through Particular Conditions, for example requiring Employer approval for variations above a financial threshold. A contractor should insist that any such limits are written into the contract; otherwise the Engineer’s authority is as stated in the General Conditions.

The Silver Book: Employer’s Representative in place of the Engineer

The Silver Book (EPC/Turnkey) is designed for projects where the Contractor takes design responsibility and the Employer wants price and time certainty. It does not have an Engineer. Under Sub-Clause 3.1 the Employer may appoint an Employer’s Representative to act on its behalf, and must notify the Contractor of the name, address, duties and authority. Unless notified otherwise, the Employer’s Representative is deemed to have the full authority of the Employer under the Contract, except for termination by the Employer. Replacement requires not less than 14 days’ notice.

Where the Silver Book says the Employer shall proceed under Sub-Clause 3.5, it is the Employer itself, rather than an independent professional, that must consult and make a fair determination. If the Contractor is dissatisfied, it must give notice within 14 days and the dispute can be referred to the Dispute Adjudication Board. In practice the Employer’s Representative performs this function, so the contractor is dealing with the Employer’s own appointee. This is one reason contractors on Silver Book projects tend to scrutinise Particular Conditions and ask for a clear, defined path to adjudication.

For a comparison of the three forms and when each is appropriate, see our analysis of choosing between the FIDIC Red, Yellow and Silver Books in Vietnam.

Comparing the roles side by side

The table summarises how the Engineer role FIDIC construction Vietnam contracts use differs from the Silver Book and statutory roles.

Feature	Engineer (Red / Yellow)	Employer’s Representative (Silver)	Supervision consultant (Vietnamese law)
Source of role	Contract (Clause 3)	Contract (Sub-Clause 3.1)	Construction Law and supervision/quality regulations
Appointed by	Employer	Employer (optional)	Owner
Authority	As stated or necessarily implied in the Contract; no authority to amend	Full Employer authority unless limited, except termination	Statutory supervision and acceptance functions; scope set by contract and law
Neutral decision-making	Fair determination under Sub-Clause 3.5	Employer determines fairly under Sub-Clause 3.5	Not a neutral adjudicator; acts for the owner
Individual qualification	Qualified engineers and staff as the Contract requires	Not specified in the General Conditions	Practising certificate for supervision roles (Construction Law, Art. 88(1))
Typical outputs	Instructions, certificates, determinations	Instructions, approvals, notices	Supervision records, acceptance records, confirmation of quantities

The statutory role is not a substitute for the contractual one, and vice versa. A contract that appoints a Vietnamese supervision consultant to “act as the Engineer” without defining powers risks leaving both roles ambiguous.

Vietnamese law on supervision and qualifications

Practising certificates and capacity disclosure

Under Article 88(1) of the Construction Law No. 135/2025/QH15 (effective 1 July 2026), individuals holding the title of construction supervisor must hold a practising certificate, graded I, II or III. Under Article 88(5), the owner bears responsibility for selecting the organisations and individuals it engages. Under Article 88(6), organisations disclose their own capacity information on the Ministry of Construction’s website, which owners may use as a reference when selecting contractors.

Decree 212/2026/ND-CP, Article 41, implements the disclosure on the national database at csdlhdxd.gov.vn. In our reading, the Law no longer makes a capacity certificate for organisations a mandatory condition; qualifications attach primarily to individuals. Check transitional rules for any older certificates before relying on them.

For a foreign engineer or firm proposed as Engineer or supervisor, check separately whether foreign practising certificates are recognised, which secondary sources suggest turns on the length of stay and requires legalisation or conversion under Decree 212/2026. Foreign contractors are also subject to the licensing regime in Article 88(3) and Decree 212/2026, which is outside this article.

Acceptance, quantities and payment

Article 9 of Decree 210/2026/ND-CP, which replaced Decree 50/2021 from 1 July 2026, requires the parties to agree which works must be accepted, on what basis and by what procedure, with what personnel, on which forms and signed by whom. The contractor must give advance notice of works requiring acceptance before moving to the next stage, and defective work is to be inspected, assessed and remedied or replaced at the cost of the party responsible.

Article 30 provides that the final account file is prepared by the contractor and confirmed by the employer’s representative or consultant and the contractor. In other words, the person who signs matters, so the contract should name the signatories and the authority of each. Our article on acceptance and handover on Vietnamese construction projects develops this.

Decree 210/2026, Article 17(3), also contemplates a dispute-resolution board on international practice for contracts that adopt it, with the parties setting its timing, members, binding effect and procedure. This is the contractual counterpart to a FIDIC Dispute Adjudication Board, and its design bears directly on how far an Engineer’s determination is likely to be final in practice.

Where the Engineer role goes wrong in practice

The following failure modes are drawn from general market practice rather than any statute, and recur on projects with international contract forms and local supervision teams.

• Unclear delegation. The Engineer’s name is in the contract, but day-to-day instructions come from a site team whose authority was never notified in writing. The contractor then cannot show that the instruction bound the Employer.
• Instructions by informal message. Site instructions are given by phone or messaging application and never confirmed, so a later variation or delay claim has no clean starting point.
• Parallel sign-offs. The FIDIC certificate is signed by the Engineer, while the Vietnamese acceptance record is signed by a different consultant, on a different date and for a different scope.
• Conflicted determinations. The Engineer is asked by the Employer to reject every claim, and the determination under Sub-Clause 3.5 becomes a formality that is predictably referred to the Dispute Adjudication Board.
• Uncertified staff. A named supervisor lacks the right practising certificate, which gives the owner a regulatory problem and the contractor a reason to question the validity of sign-offs.

A hypothetical illustration: on a private industrial plant, the owner appoints a Vietnamese supervision consultant and, separately, a foreign firm as Engineer. The Particular Conditions say only that the consultant “assists” the Engineer. A variation is instructed by the consultant on site and not countersigned by the Engineer. When the Employer later refuses payment, both sides argue about whose instruction counted. Clear delegation and a single instruction channel would have avoided the dispute.

These issues are cheap to fix at drafting stage and expensive to fix during a claim. They are the practical core of the Engineer role FIDIC construction Vietnam contracts require parties to administer.

How far is an Engineer’s decision final?

An Engineer’s certificate or determination is not the last word. Under the FIDIC 1999 text, either party may refer a dispute about a determination to the Dispute Adjudication Board, and arbitrators have full power to open up, review and revise any certificate, determination, instruction, opinion or valuation of the Engineer (the Employer in the Silver Book), and any DAB decision. On a Vietnamese project this means a certificate that looks decisive may be revisited in arbitration. It also means a contractor that signs a certificate without reservation may later struggle to withdraw from it.

Practical drafting and project steps

1. Define the roles in the Particular Conditions. State whether the Engineer or Employer’s Representative is separate from the supervision consultant, and who signs statutory acceptance records.
2. List authority limits. Require the Employer to disclose financial and scope limits on the Engineer’s authority, and provide that an action within the Contract’s terms binds the Employer.
3. Put independence on paper. If the Engineer is employed by the Employer or an affiliate, require a conflict policy and, ideally, a separate determination team.
4. Confirm oral instructions. In the harmonised text an oral instruction can become written if the Contractor confirms it in writing within two working days and there is no objection within two working days; use this deliberately.
5. Check individual qualifications. Verify practising certificates for named supervisors, and make replacement of named persons subject to notice and approval.
6. Keep paper trails aligned. A FIDIC certificate and a Vietnamese acceptance record may be signed by different people on different dates; reconcile them.

Lenders should note that a lender’s technical adviser or independent engineer is a separate appointment under the financing documents, not the FIDIC Engineer, even if the same firm sometimes fills both. Their reporting lines and duties should not be conflated.

You can read the Construction Law text on hethongphapluat.com when checking article references.

Engineer role FIDIC construction Vietnam across project types: infrastructure, industry, energy and real estate

The Engineer role is a contract construct, but the person who fills it and the powers delegated to them depend on the owner and sector. The examples are hypothetical.

Infrastructure and transport

Expressways, ports, metro, rail stations and airport terminals are often State- or SOE-owned and so often treated as public investment or PPP; classification depends on the funding source of each project. The project management board and the supervision consultant then often occupy roles that overlap with the Engineer, so the appointment documents must say who decides and who certifies.

For very large schemes such as the planned North–South high-speed railway (about 1,541 km, 15 provinces and cities, 350 km/h design speed), different sections may have different supervisors, which makes delegation notices critical. On an airport terminal such as phase 1 of Long Thành International Airport (commercial operation expected from 24 December 2026 per press reports), technical systems packages need an Engineer with matching expertise.

Heavy industry and factories

Steel, petrochemical and cement plants and FDI factories often use turnkey forms. Under the Silver Book there is no Engineer, but an Employer’s Representative, and owners sometimes appoint an independent engineer for lenders. That lender’s engineer is a different role again.

Renewable energy and power

Solar, wind and gas-to-power projects often have a lender’s technical adviser alongside the contract administrator. Sub-Clause 3.5 determinations concerning testing and grid-connection milestones may affect the revenue date, so impartiality is tested. Ownership and offtake structure determines the legal regime.

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

For resorts, hotels and mixed-use developments, the owner often appoints an architect or project manager as contract administrator. If that person is not the contractual Engineer, instructions can be challenged as unauthorised. Party agreement governs.

Sector	Typical administrator	What to check
Expressway, rail, airport terminal	Management board plus supervision consultant	Which body certifies; delegation
Factory, steel, cement	Employer’s Representative (Silver Book)	Lender’s engineer; authority limits
Solar, wind, gas-to-power	Engineer plus lender’s adviser	Independence on milestone decisions
Resort, hotel, mixed-use	Architect or project manager	Formal appointment as Engineer

Conclusion

The Engineer role FIDIC construction Vietnam parties assume exists on paper may differ from the one that exists in the Particular Conditions and on the ground. Under the FIDIC 1999 edition the Engineer acts for the Employer yet must determine fairly under Sub-Clause 3.5; the Silver Book substitutes an Employer’s Representative; and Vietnamese law attaches separate statutory duties to the supervision consultant. A sensible first step is to compare your contract’s appointment documents, delegation notices and statutory supervision appointments, and to resolve any gaps before the next certificate falls due.

Frequently Asked Questions

Is the FIDIC Engineer independent of the Employer?

Not generally. The Engineer is treated as acting for the Employer, but must consult both parties and make a fair determination when the contract requires a determination under Sub-Clause 3.5.

Does the Silver Book have an Engineer?

No. The Silver Book provides for an optional Employer’s Representative, who acts on the Employer’s behalf and is deemed to hold full authority unless limited, except for termination.

Can the Vietnamese supervision consultant act as the FIDIC Engineer?

It can if the contract says so and defines the powers. The roles have different sources, so the Particular Conditions should state who performs which function and who signs which record.

Do supervisors in Vietnam need a practising certificate?

Under Article 88(1) of the Construction Law, individuals acting as construction supervisors must hold a practising certificate in the relevant grade. Foreign certificates need separate checking.

Is an Engineer’s determination final?

No. Either party can refer it to the Dispute Adjudication Board and, if still dissatisfied, to arbitration, where the tribunal can revise any certificate or determination.

Disclaimer: this article provides general information as of 22 October 2026 and is not legal advice on any specific matter. Contract wording, governing law and facts will change the analysis.