Before building a factory, every FDI employer faces its first contracting decision: split design and construction into two contracts with two different partners, or bundle everything into one turnkey EPC contract. That choice decides who controls the design, who carries material price risk and who must sort it out when the design does not fit the construction. No model is right for every project; there is only the model that fits each project’s management capacity and complexity.
The separate model: design control in exchange for interface risk
Under the separate model, the employer contracts an independent design consultant, completes the design documents and cost estimate first, and only then tenders or appoints a construction contractor against that fixed design. The greatest advantage is control: the employer works directly with the designer, settles solutions, materials and standards to its own preference, and holds a complete design package on which several contractors price the same basis, creating real price competition. Construction cost under this model is usually lower than EPC because there is no general-contractor risk premium and no layered management fee.
The price of control is that interface risk returns to the employer. When construction reveals design gaps or unbuildable details, the contractor has grounds to claim variations and extensions because the design is not theirs; designer and contractor readily push responsibility back and forth while the employer sits in the middle. The separate model also demands a project management team strong enough to run two contracts, approve designs on time and resolve interface conflicts — a capacity not every FDI investor has in Vietnam on its first project.
The EPC model: one throat to choke, at a price
Under EPC, the employer defines only the output requirements — capacity, technology, standards, deadline — and hands detailed design, procurement and construction to one general contractor with sole responsibility. When design does not fit construction, that is the contractor’s internal problem, not a basis for variation claims against the employer. Schedules are usually faster because design and long-lead equipment procurement run in parallel with the first construction packages. The model fits employers with thin local staffing, projects needing speed, or technology held by the contractor itself.
EPC’s drawbacks are price and flexibility. The contractor loads the price with contingency for every risk transferred to it, so the total usually exceeds the separate model for the same scope; the employer also struggles to verify item pricing because EPC quotations rarely break down in detail. Every post-signing change of requirements becomes an expensive variation because the employer’s competitive leverage is gone. Design quality also depends on the contractor’s own standards; if the output requirements are loosely written, the contractor is entitled to choose the cheapest solution that minimally complies.
Choosing by project type
Three questions structure the decision. First, is the project technologically complex, demanding tight equipment and process integration — electronics, pharmaceutical or international-standard food plants? If so, EPC or an integrated model with a technology-capable contractor is usually safer, because performance responsibility needs a single home. Second, does the employer have a technical team in Vietnam strong enough to manage a separate design contract and coordinate interfaces? If so, the separate model converts that capacity into real savings. Third, which matters more for this project: certainty of total budget and schedule, or cost optimisation and detailed control? Whichever side the answer leans to, the matching model wins.
In practice many FDI projects choose a hybrid: EPC for the production halls and technology-linked technical infrastructure, separate contracts for the office, canteen and simple buildings; or a separate design contract through the basic design stage, then EPC built on that design package to reduce the loose-output-requirements risk. Whichever model is chosen, the design-responsibility boundary must be written as a clear contract clause, because it is the first crack that opens when a dispute arrives.
Frequently Asked Questions
Should design and construction be separate contracts or one EPC package?
It depends on management capacity and project complexity. Separate contracts fit employers with a local technical team who want design control and price optimisation through competition. EPC fits employers with thin staffing who need speed and a single point of total responsibility including performance. Large projects often choose a hybrid by work package.
Separate design gives better control — what are its downsides?
The main downside is interface risk sitting with the employer: design gaps become the contractor’s basis for variation and extension claims; designer and contractor push responsibility to each other; and design approval sits on the employer’s critical path. The model also costs more internal project management and is usually slower than EPC because design must finish before construction proceeds in full.
Under turnkey EPC, who bears material price risk?
The EPC contractor, within the lump sum: movements in material and equipment prices during performance are the contractor’s and are priced in, unless the contract carries an index-based adjustment clause for key materials. That is part of why EPC prices exceed the sum of equivalent separate packages.
Which model suits a high-technology factory with complex technical requirements?
EPC, or an integrated model with a technology-holding contractor, usually suits better because responsibility for performance, equipment integration and commissioning must rest in one place. The condition is output requirements written tightly enough on capacity, parameters and performance acceptance criteria; loose requirements erode the single-responsibility advantage through minimum-cost solutions.
Practical recommendations
Employers should decide the contracting model by answering honestly about their own team’s capacity before looking at prices: a strong team turns the separate model into savings and control; a thin team buys certainty with EPC at a higher price. In both cases, the decision record should state the reasons and the design-responsibility boundary, because those are the first two things read again if the project lands in dispute.
This article has been quality-reviewed by the FLAW AI Legal Council