On the first day of the Institute's BIM Coordinator course, the question asked most often is: "what is the difference between BIM 4D and 5D, and which software does my company have to buy to do it?". It sounds simple, but the answers found online are usually wrong in two ways. One treats the "dimensions" as rungs on a ladder to be climbed in order. The other assigns each dimension to one piece of software, when in reality each dimension is a type of information attached to the model, and several tools can do the attaching.
This article explains each dimension from 3D to 7D in terms of what information is added to the model and which question it answers. It then lists the software actually used at each level, says plainly how far Vietnam has got, and suggests what people in each role should learn.
What a BIM "dimension" means, and why the term is not standardised
"BIM 4D" means taking the 3D model and attaching one more type of information: time. "5D" attaches cost. The shorthand is convenient, but three things need saying at the outset.
First, no international standard defines the dimensions. The ISO 19650 series on information management using BIM never uses 4D or 5D; it talks about information requirements for each stage of a project. NBS, the UK body behind much BIM guidance, observes that the industry agrees as far as 4D and 5D and that beyond that "there is little international consensus". They add that cost is arguably not a "dimension" at all, merely one more information field.
Second, 6D and 7D swap places depending on the source. Many documents call 6D operations and maintenance and 7D energy and sustainability; plenty of others have it the other way round. This article uses the more common order, but when you read a vendor's or a partner's material, check their definition before comparing.
Third, and most important for practitioners: the dimensions are not a ladder. A project can do 5D very well without doing 4D at all. The general BIM guidance published by Vietnam's Ministry of Construction under Decision 348/QD-BXD of 2 April 2021 lists "construction schedule simulation and management (BIM 4D)" and "cost estimating (BIM 5D)" as application objectives for the client to choose from, not as mandatory levels. The document does not mention 6D or 7D.
BIM 3D: a model that carries information, not "3D drawing"
3D is the base for every other dimension, but 3D in the BIM sense is nothing like a 3D shape. Every component in the model has to know what it is: how thick this wall is, how many layers it has, which storey it belongs to, whether it is load-bearing. What is BIM? covers this in detail; LOD in BIM covers how detailed that information is.
The question 3D answers: what is where, and do the disciplines collide. The biggest value of 3D is coordination: architecture, structure and MEP each build a model, link them together and check for clashes before anything reaches site.
Modelling software: Revit (architecture, structure, MEP), ArchiCAD (architecture), Tekla Structures (steel and concrete structures), Allplan, Civil 3D for infrastructure. Open-source software such as FreeCAD can also build a BIM model and export IFC, though it is rarely used on real projects in Vietnam.
Federation and checking software: Navisworks, Solibri, Trimble Connect, BIMcollab. They read models from different authoring tools through the common IFC format, combine them and find clashes. The person who coordinates those models is the BIM Coordinator; the Institute's BIM Coordinator course spends most of its time on exactly that — coordination and clash resolution on the federated model.
BIM 4D: attaching time to the model
BIM 4D is a 3D model in which every component is linked to an activity in the programme. Drag the time slider and you watch the building "grow" week by week: slab of floor 5 poured in week 12, column reinforcement on floor 6 fixed in week 14, where the crane stands, where materials are stored.
The question 4D answers: what is done when, and does that sequence make sense. The errors 4D typically catches: two crews occupying the same space in the same week; a haul route blocked by work already built; a construction method that needs clear space the design has already filled.
The point beginners misunderstand: 4D does not produce the programme. The programme still has to be built in scheduling software, with its activity list, durations and logic links. The 4D model only connects that programme to the components. A wrong programme simulates just as smoothly, and is just as wrong.
Scheduling software: MS Project, Primavera P6, Asta Powerproject. In Vietnam, MS Project is the most common among domestic contractors; P6 is common on foreign-funded projects and large infrastructure. What is MS Project? and the Institute's MS Project course are where to start on this part.
Software that links the programme to the model: the TimeLiner tool in Navisworks reads programmes from MS Project, Primavera P6, Asta and CSV files, assigns them to model objects and runs the simulation. It is the most common way of doing 4D today and forms one chapter of the Navisworks Manage course. Bentley's Synchro 4D goes further: it integrates with P6 and Asta, handles detailed construction methods, tracks actual progress from site, and includes model-based quantity take-off. Synchro is usually found on infrastructure projects and with large general contractors.
BIM 5D: attaching cost to the model
BIM 5D takes quantities from the model, multiplies them by unit rates to produce a cost, and updates that cost whenever the model changes. The question 5D answers: how much does this option cost, and how much does the cost change if the design changes.
For estimators this is the biggest change in working method for years — and also the dimension most easily oversold. Three things need saying plainly:
- Quantities from the model are only correct when the model is built correctly and completely. Beams drawn as lines instead of objects, or members not split by the conditions in the norms, produce wrong quantities that look very tidy.
- Many items still have to be measured separately: formwork, earthworks, detailed finishes, anything not modelled. What is quantity take-off? sets out that boundary.
- 5D does not replace someone who understands estimating. The software provides quantities and multiplication; choosing the norm code, handling items with no code, and judging whether the figure is plausible remain the engineer's job. Anyone not yet solid on estimating should take the Construction Cost Estimating course before touching 5D.
Software for 5D: Revit generates quantity schedules from the model, enough for concrete, walls and doors at design stage. Navisworks has a Quantification tool with three take-off methods: from model objects, "virtual" take-off for items not in the model, and take-off on 2D sheets. Cubicost from Glodon is a dedicated 5D suite distributed in Vietnam: it accepts Revit and IFC models and comprises modules for architectural and structural take-off, reinforcement, MEP and pricing; the architectural-structural module holds buildingSMART IFC certification. Synchro 4D also includes model-based take-off.
The common workflow in Vietnam today is hybrid: quantities come from the model, are exported to Excel, then go into a domestic estimating package (G8, Eta, GXD and others) for norms and unit rates under the regulations in force. The new cost-management framework effective 1 July 2026 encourages taking quantities directly from the BIM model, so this part will keep developing quickly.
BIM 6D and 7D: operations and maintenance, energy and sustainability
These two are rarely done in Vietnam and are regularly confused with each other, so this article separates them by the type of information rather than by number.
Operations and maintenance information (usually called 6D): every piece of equipment in the model carries an asset code, supplier, installation date, maintenance interval and manuals. After handover, the building operator uses the model to locate equipment, schedule maintenance and log repairs. The question it answers: where is this unit, who supplied it, when must it be replaced. The familiar exchange format here is COBie, an asset data table exported from the model.
Software: Autodesk Tandem is Autodesk's digital-twin platform, commercially available since 2021, which takes Revit and IFC models to build the asset record for the operations phase. Alongside it are facility-management systems that pre-date BIM — Archibus, IBM Maximo, Planon — which now take data from the model. For infrastructure, the operations model is usually tied to GIS; GIS integrated with BIM covers that direction.
Energy and sustainability information (usually called 7D): the model carries data on the envelope, orientation and energy-consuming equipment, so that the energy use and carbon emissions of an option can be calculated. The question it answers: how much energy does this option use per year, and how much is saved by changing a material.
Software at this level changes fast. Two familiar Autodesk tools, Insight Energy Analysis and Green Building Studio, were retired during 2025 and replaced by Insight Carbon Analysis, which runs inside Revit from version 2023.1. Outside Autodesk there are IES VE, DesignBuilder and tools built on the EnergyPlus engine. If older material mentions Green Building Studio, be aware it no longer works.
As for 8D (safety), 9D, 10D and so on, which appear in some articles and marketing material: no standards body recognises them, and every source defines them differently. You do not need to remember them.
Summary table: what each dimension adds, which software, who uses it
| Dimension | Information added | Question answered | Typical software | Main user |
|---|---|---|---|---|
| 3D | Geometry + component properties | What is where, are there clashes | Revit, ArchiCAD, Tekla, Civil 3D; federated in Navisworks, Solibri | BIM technicians, BIM Coordinator |
| 4D | Time | What is done when, is the sequence sound | MS Project, Primavera P6 for the programme; Navisworks TimeLiner, Synchro 4D for simulation | Planners, the contractor's BIM Coordinator |
| 5D | Cost | How much, and how much does a change cost | Revit schedules, Navisworks Quantification, Cubicost; priced in G8, Eta, GXD | Estimators, QS |
| 6D | Operations, maintenance | Where is the equipment, when is it serviced | Autodesk Tandem, Archibus, Maximo; COBie data | Facility managers, owners |
| 7D | Energy, carbon | How much energy, how much emission | Insight Carbon Analysis, IES VE, DesignBuilder | Energy engineers, green-building consultants |
The table shows why nobody can "buy one piece of software to do BIM 5D": every dimension needs at least two tools, one to create the information and one to attach it to the model.
How far Vietnam has got
Legally, Decision 258/QD-TTg of 17 March 2023 sets the roadmap: from 2023, BIM is mandatory for grade I and special-grade buildings on new projects funded by public investment, other state capital or PPP; from 2025 this extends to grade II and above. Decree 217/2026/ND-CP then went further: from 1 July 2026, every new work of grade II or above must apply BIM from the feasibility study stage, whatever the source of funding. The roadmap requires applying BIM, with the level of application decided by the client; the general guidance under Decision 348/QD-BXD lists 4D and 5D as objectives to choose from.
On standards, ISO 19650 has been adopted as national standards TCVN 14177-1:2024 and TCVN 14177-2:2024, published in December 2024, with application guidance issued by the Ministry of Construction. These standards deal with information management across the life of the asset, and likewise do not use the 4D, 5D labels.
In practice, from the projects our lecturers work on and from students already in employment:
- 3D coordination is done most, and done best. Most projects where BIM is mandatory stop here: three discipline models, federated, clash-checked, drawings issued from the model.
- 4D appears on large general-contractor projects and infrastructure, mainly for presenting construction methods and for progress meetings. Many teams build the 4D once to present to the client and never update it — at which point it is an animation, not a management tool.
- 5D is growing fastest, because it is directly about money and because the new cost regulations encourage it. Most of it is still hybrid: quantities from the model, pricing in domestic software.
- 6D and 7D are very rare. Clients seldom require operations data in the handover package, and the market has no habit of model-based energy calculation outside projects seeking green-building certification.
In short: if your company does 3D coordination well and is starting on 5D, you are in the leading group in Vietnam. Do not rush to spend on 6D software while nobody on the project needs operations data.
Which dimension to learn for which role
Nobody needs all seven. Choose by the work you do:
- Technicians and modelling engineers: get 3D right — real objects, complete properties, members split by the conditions in the norms. This is what keeps 4D and 5D downstream from going wrong. The Revit courses by branch are the starting point.
- BIM Coordinator: 3D coordination and 4D. The BIM Coordinator course for coordination; Navisworks for clashes and TimeLiner; MS Project to understand the programme you are linking to the model.
- Estimators and QS: 5D. Get estimating solid first, then learn to read a model and extract quantities; Navisworks Quantification or Cubicost depending on the company.
- Planners and site managers: 4D. MS Project or P6 for the programme, Navisworks for simulation and meetings.
- BIM Managers, clients and project management units: no need to operate each dimension in depth, but you must know what information requirements each dimension needs so they can go into the tender documents and the BIM execution plan. The Institute's BIM Manager course covers exactly this: implementation planning, model quality assessment, quantity control, the common data environment. What is a BEP? describes the document those requirements go into.
Frequently asked questions
Are BIM 4D and 5D mandatory in Vietnam?
No. Decree 217/2026 makes applying BIM mandatory for new works of grade II and above, but says nothing about which dimensions to reach. The level is the client's decision. The Ministry of Construction's general guidance lists 4D and 5D as objectives to choose from; both are built on the 3D model.
Do I have to finish 4D before I can do 5D?
No. The two are independent: 5D needs quantities from the model and unit rates, not a programme. Many projects in Vietnam do 5D without doing 4D.
Can Revit do 4D and 5D?
Revit builds the model and generates quantity schedules, which is part of 5D. Revit does not simulate the programme; 4D is done in Navisworks, Synchro or a similar tool, with the programme built in MS Project or P6.
What do I need to know before learning BIM 4D?
Two things: how to read a model (at least at Navisworks level) and how a construction programme works — the activity list, durations and logic links. Without the second you can only produce an animation, not check whether the programme makes sense.