If you work in construction and still cannot answer what is BIM in one sentence, you are not alone. Plenty of engineers with five to ten years behind them still think BIM means "drawing in 3D with Revit". That is not entirely wrong, but it is like calling a smartphone "a device for making calls": a small part of the truth, missing everything that matters.
This article explains BIM in a way someone outside the industry can follow, using an example our lecturers still tell in the first session. It also answers the two most practical questions: how far Vietnam's mandate now goes, and where to start if you want to learn.
BIM is not a piece of software
The shortest honest answer to what is BIM starts by clearing away the most common misunderstanding. BIM (Building Information Modelling) is a way of working, not a product you buy and install.
Revit, ArchiCAD, Tekla and Navisworks are tools that support BIM. You can open Revit, model a very handsome 3D house, and still not be doing BIM at all — when the model is geometry only, carries no information, is not shared between the parties and follows no data management process.
Conversely, a project team can do proper BIM with a range of different tools. The condition is that they agree on three things: a shared model, information attached to that model, and a process that keeps everyone updating one source of data.
In Vietnam, Revit is the most widely used modelling tool, which is why the Revit courses are usually where beginners enter. But remember: finishing a Revit course means you can use the tool, not that you are doing BIM.
The international standard for managing information with BIM is the ISO 19650 series, published in December 2018 — and strikingly, it says almost nothing about software. It talks about information: who produces it, who needs it, when it is delivered, how it is checked. Vietnam has adopted the first two parts as TCVN 14177-1:2024 and TCVN 14177-2:2024.
Three letters, three meanings
The quickest way to understand BIM is to take the acronym apart.
B – Building. Not only buildings. Bridges, roads, plants and substations are all "buildings" in this sense — and in Vietnam, infrastructure BIM is growing just as fast as the building sector.
I – Information. This is the most important letter and the one most often ignored. On a CAD drawing, a wall is four lines. In a BIM model, that wall knows how thick it is, what it is made of, whether it is load-bearing and which storey it belongs to. It also knows who supplied it and how often it needs maintenance, and that information travels with it for the whole life of the asset.
M – Modelling. The process of building and maintaining that model through the stages: design, construction, operation. "Modelling" is a verb — continuous work, not a file you finish and file away.
The table below summarises the core difference between the old way and the BIM way:
| Criterion | 2D CAD drawing | BIM model |
|---|---|---|
| Objects | Lines, arcs, text | Walls, beams, doors, pipes… carrying properties |
| Changing one thing | Edit by hand on every related sheet | Plans, sections and schedules update themselves |
| Quantities | Measured by hand off the drawings | Extracted directly from the model |
| Clash detection | Once it is built | Before construction, on the model |
| Discipline coordination | Files emailed back and forth, versions drift | One model, with a controlled process |
| After handover | As-built drawings on paper | An operation and maintenance model |
An example: a duct running through a transfer beam
This story explains BIM better than any definition. A 15-storey office building. The structural team designs a 1.2 m deep transfer beam at level 3. The MEP team routes the main duct straight through that same space. The two disciplines work on separate CAD sets, email them to each other, and each is "correct" on its own drawings.
The old way, the clash only surfaces once the crew has poured the beam and started installing the duct. At that point there are two options: cut the beam (impossible, it is a transfer beam) or drop the level 3 ceiling by 40 cm — which drags the whole electrical, lighting and fire-protection layout of that floor with it. The delay is measured in weeks.
With BIM, the structural and MEP models are brought into one environment, usually Navisworks. The software runs clash detection automatically and reports it: the duct passes through the transfer beam. Two engineers sit down for twenty minutes and move the duct. The cost of that fix: near zero.
That is the value of BIM — not a handsome 3D model, but finding and solving problems at the cheapest possible stage.
What BIM 3D, 4D and 5D mean
You will meet the labels "BIM 4D" and "BIM 5D" constantly. They are not standardised terms, just shorthand for what kind of information has been attached to the model: 4D is time (programme simulation), 5D is cost, 6D is operation and maintenance.
A project does not need all "seven dimensions" to count as BIM. Most projects in Vietnam do 3D well and are starting on 4D and 5D. What BIM 3D, 4D, 5D, 6D and 7D mean goes through each dimension and the software for each stage; the level of detail in a model is governed by LOD, explained in What is LOD in BIM.
Where BIM stands in Vietnam
This is the part most often got wrong. The main legal milestones:
- 22/12/2016 – The Prime Minister issues Decision 2500/QD-TTg approving the scheme for applying BIM in construction and asset operation. This is the official starting point.
- 11/10/2017 – The Ministry of Construction publishes interim guidance (Decision 1057/QD-BXD) for the pilot phase.
- 02/04/2021 – The Ministry issues Decision 348/QD-BXD with general BIM guidance, replacing the interim document. Decision 347/QD-BXD of the same day covers detailed guidance for buildings and urban technical infrastructure.
- 17/03/2023 – The Prime Minister issues Decision 258/QD-TTg approving the BIM roadmap. This is the document that moved BIM from "encouraged" to "mandatory", in two stages: from 2023 for grade I and special-grade works funded by the state, and from 2025 down to grade II.
- 19/06/2026 - The Government issues Decree 217/2026/ND-CP, setting out the Building Law in detail and replacing Decree 175/2024/ND-CP. This is the instrument now governing BIM, in force from 1 July 2026.
The rules in force sit in Article 8 of that decree, and three points matter.
Under point a, clause 1, every new construction work of grade II and above must apply BIM from the feasibility study stage. This requirement does not distinguish by source of funding, unlike the earlier roadmap, which targeted state-funded projects only. The investment decision-maker may grant exemptions only in specific cases, such as linear works or works involving state secrets.
Under clause 4, BIM data is defined as a digital resource. The same clause requires the client to establish and operate a common data environment (CDE) on grade I works and above within public investment projects.
Under clause 5, on completion the as-built model has to be uploaded to the national construction activity database.
For projects in scope, the BIM files form part of the design documentation and the completion records: no model means the submission is incomplete.
On the industry side, a Vietnam Report survey published in April 2025 found the share of construction firms applying BIM at a high level rising from 65.0% to 73.1%. Read that carefully: the survey covers large firms, and "applying at a high level" is not the same as running a full ISO 19650 process. But the direction is clear.
The direct consequence for people working in the field: BIM technicians, modellers and BIM Coordinators are being recruited in volume. At many design firms, a CV without Revit is cut in the first round.
Who needs to learn BIM, and what
The answer depends on where you sit in a project — learning the wrong thing is the fastest way to spend money you cannot use.
Students and young engineers and architects – need modelling skills, starting with Revit in their own discipline: architecture, structure or MEP. This is the largest group and the easiest to place once the skill is there.
Engineers with three to five years' experience – are usually asked to coordinate models across disciplines: they need Navisworks for clash detection, an understanding of the common data environment (CDE) and of the coordination process. That is the BIM Coordinator role.
Department heads, lead designers, project managers – do not need to model well, but must be able to write a BIM execution plan (BEP), draft information requirements (EIR), organise the team and accept models. That is the BIM Manager role, built on ISO 19650 and the Ministry's general guidance.
Clients and project management units – need enough understanding to set the right requirements in tender documents and to accept a model. This is the group left shortest of people by Decision 258.
For a company moving a whole team onto BIM, the Institute runs training on request. The programme is designed for that company, taught on its own project documents, with advice on process and a shared library — see In-house Revit and BIM training for companies.
Where to start
Knowing what is BIM only gets you to the start line; the harder part is turning that understanding into skills a project can use. Our lecturers settle on a three-step path for most beginners:
- Get solid in one modelling tool first. For most people that is Revit. Do not learn three tools at once — model one complete building with one tool and issue the drawings and schedules from that model. This stage takes roughly two to three months of guided study.
- Learn to coordinate. Put your model into a shared environment, check it against other disciplines, and understand why naming and version control follow a convention. This is where BIM starts to differ from "3D drafting".
- Learn information management once you are responsible for the whole project's model. ISO 19650, the BEP, roles and responsibilities — these only sink in after the first two steps.
If you want to follow that path with a teacher, the Institute runs 6 Revit courses for step one, the BIM Coordinator course for step two and the BIM Manager course for step three. Certificates carry the name of Hanoi University of Civil Engineering.
Frequently asked questions
What is the difference between BIM and Revit?
BIM is a way of working with a shared, information-carrying model; Revit is one piece of software for building that model. Using Revit does not automatically mean doing BIM, and doing BIM does not require Revit — though in Vietnam Revit is the most common tool.
Which projects in Vietnam must apply BIM?
Under point a, clause 1, Article 8 of Decree 217/2026/ND-CP, in force from 1 July 2026: every new construction work of grade II and above must apply BIM from the feasibility study stage. The requirement does not distinguish by source of funding. The investment decision-maker may grant exemptions only in specific cases, such as linear works or works involving state secrets.
Can someone without a construction degree learn BIM?
Yes, up to modelling and coordination — but they also need to read drawings and grasp the basics of structure and MEP to understand what they are modelling. How to read construction drawings is a sensible starting point.
How long does it take to learn BIM?
To model one discipline confidently in Revit: about two to three months of steady study. To coordinate a multi-discipline model: another one to two years of real work. The BIM Manager role usually needs five years of project experience or more.
Will BIM replace engineers?
No. BIM changes what engineers do rather than removing them: time once spent redrawing and cross-checking sheets moves to checking, coordinating and deciding earlier.