Building information modeling (BIM) means designing, building and running an asset around one shared digital model whose elements are objects carrying data, not lines on a drawing. In Singapore, BIM submissions in IFC+SG format are mandatory for new erections and major A&A works with new GFA of 5,000m² or more.
The definitions below come from ISO, buildingSMART International and the BIMForum Level of Development Specification. The Singapore rules come from BCA and URA circulars and from BCA's IFC+SG Knowledge Hub, each linked at the point it is used. BCA and URA revise their requirements, as the July 2026 CORENET X circular showed, so treat this page as correct at 9 October 2026 and let your Qualified Person confirm anything a submission depends on. Where something is not published officially, we say so.
What BIM is: a model, not a set of drawings
A CAD drawing is a collection of lines that a trained person reads as a wall, a door or a beam. The software does not know what any of them are. In a BIM model the wall is an object: it knows it is a wall, what type of wall, which storey it stands on, how high it is and what properties it carries, such as fire rating or finish. Plans, sections, elevations and schedules are then views generated from that one model. Move a wall and every view that shows it changes with it, which is why BIM drawings stay consistent with each other in a way that separately drafted sheets often do not.
The "I" is the point. ISO's ISO 19650-1:2018 frames BIM as information management: its abstract describes recommendations for exchanging, recording, versioning and organising information for everyone involved, across the whole life cycle of a built asset, from strategic planning and design to operation, maintenance, refurbishment and end of life. The geometry matters, but a BIM model is valuable because other people and other software can read the information in it reliably.
That reading usually happens through IFC, the Industry Foundation Classes. buildingSMART International describes IFC as a set of standardised digital descriptions of the built asset industry, published as an open standard under a Creative Commons licence and as ISO 16739, and vendor-neutral. A Revit file is Autodesk's format; an IFC file is the shared one that a regulator, a contractor or a facilities system can open without owning the software that produced it.
What a BIM model contains
The content varies with the purpose, but a working BIM model normally holds:
- Elements as typed objects: walls, slabs, columns, beams, doors, windows, stairs, roofs, and for services, ducts, pipes and equipment. Each belongs to a type that can be scheduled and counted.
- Properties: data attached to each element. In IFC these sit in property sets, and Singapore adds its own, as our IFC+SG model guide explains.
- A spatial structure: project, site, building, storey and space, so every element is placed on a level and every room is a defined space with a name and an area.
- A coordinate system: for regulatory submissions in Singapore, URA's guidance on geo-referencing BIM submissions asks for the SVY21 coordinate system for easting and northing and the Singapore Height Datum for height.
- Views and sheets: the plans, sections and elevations generated from the model, with annotation added on top.
What a model does not automatically contain is everything. Each element is only as developed, and as reliable, as the brief asked for. That is what LOD is for.
LOD: level of development, explained
LOD is the term most often misunderstood in a BIM scope. The BIMForum LOD Specification, now in its 2025 edition, uses it to mean Level of Development: the degree to which an element's geometry has been thought through, and so how far other people can rely on it. BIMForum distinguishes that from Level of Detail, which is simply how much detail is drawn. A highly detailed element placed in the wrong position is, in BIMForum's own example, no higher than LOD 200. BIMForum builds on the definitions in AIA Contract Documents and notes that terminology and numbering vary between countries.
| LOD | What it means (paraphrased from the 2025 specification) | In practice |
|---|---|---|
| 100 | A symbol or generic representation; not necessarily geometry at all. Anything derived from it is approximate. | Massing, space reservation, early feasibility |
| 200 | A generic 3D placeholder recognisable as the component, with approximate quantity, size, shape, location and orientation. | Schematic design; a background for coordination |
| 300 | Modelled so its quantity, size, shape, location and orientation can be measured from the model, fully conveying design intent. | Most design-stage architecture and structure |
| 350 | As 300, plus the interfaces with adjacent or dependent elements, enough for construction-level coordination. | Trade coordination, supports, clearances |
| 400 | Detail sufficient for fabrication, assembly and installation, roughly the level of shop drawings. | Fabrication; BIMForum notes most models contain few if any LOD 400 elements |
| 500 | Represents an existing or as-constructed condition, developed by observation, field verification or interpolation, with its accuracy stated. | Existing conditions; not a step above 400 but a different kind of element |
Three points from the specification save a lot of argument in a scope:
- LOD belongs to elements, not models. BIMForum is blunt that there is no such thing as an "LOD 300 model". Any real model mixes levels, so a good brief states the LOD per element or system: walls and slabs at one level, ceilings or services at another.
- LOD 500 is about existing things. The 2025 edition says LOD 500 is not a higher level than 400; it marks an element whose geometry comes from observing something that exists rather than designing something that will. Its accuracy must be stated separately, and BIMForum recommends the U.S. Institute of Building Documentation's Level of Accuracy (LOA) Specification for that.
- LOD is not accuracy. How fully an element is shaped and how close it is to the real thing are two separate questions. Much of the industry, ourselves included, still writes existing building scopes as LOD 200 or 300 to describe how fully each element is modelled. Whichever convention a brief uses, ask for both: what is modelled at what LOD, and to what stated accuracy.
One Singapore-specific note. For CORENET X, BCA publishes no LOD grade and no accuracy tolerance. Its requirement is correct dimensions and complete IFC+SG data, as set out on our CORENET X page. Any LOD in a Singapore BIM scope is therefore something the project team agrees, not something the regulator sets.
BIM in Singapore regulation
Singapore was early to require BIM for building approvals, and the rule has changed form more than once. The milestones that official sources state:
| When | What the official source says | Source |
|---|---|---|
| From 2013 | Mandatory BIM e-submission introduced in phases, with architectural and engineering plans submitted in BIM for regulatory approval, in step with industry capability. | BCA circular, 1 December 2020 |
| Since 2016 | BCA and URA receiving BIM submissions, particularly for new developments with GFA exceeding 5,000 sqm; models to be correctly geo-located. | URA geo-referencing guidance |
| From 1 June 2021 | New developments with GFA over 5,000m² and underground components submit a consolidated as-built BIM model of the substructure with the as-built structural plan submission. | BCA circular, 1 December 2020 |
| February 2023 | BIM described as currently mandatory for new projects with GFA of 5,000 sqm or more; an extension called IFC-SG under development for CORENET X. | Circular URA/PB/2023/01-DCG |
| Current (July 2026) | BIM submissions in IFC+SG format mandatory for new erections or major A&A projects with new GFA of 5,000m² or more. | Annex A to circular of 23 July 2026 |
The 2020 circular is worth knowing for one detail: it applies to projects whose first application for Provisional Permission or Written Permission under the Planning Act was made on or after 1 June 2021, and its stated purpose is a digitised record of underground structures to support the Underground Master Plan. It is a requirement on the structural QP of a new development, not on owners of existing buildings. The live BCA link to it no longer resolves, so the link above is an archived copy of the same PDF.
The current rule sits in Annex A to BCA and URA's circular of 23 July 2026 (APPBCA-2026-12 / URA/PB/2026/08-DCG). Its footnote defines the format: IFC is an international openBIM standard developed by buildingSMART International, and IFC+SG is an extension of it developed to cater to local regulatory requirements. All new submissions also follow the CORENET X Code of Practice.
Two things are easy to confuse here. First, the BIM test is separate from the CORENET X submission test. Since 1 October 2026 CORENET X itself is mandatory for new projects with GFA of 5,000m² and above, with major A&A measured by affected or replaced GFA, while the BIM requirement is measured by new GFA. Our CORENET X guide sets out where the two diverge. Second, "IFC" does not mean the newest IFC. buildingSMART's latest official version is IFC 4.3 (ISO 16739-1:2024), but the CORENET X Model Checker accepts IFC4 only, up to IFC4 ADD2 TC1, as our IFC+SG guide covers.
The submission itself is made by the Qualified Person, a Registered Architect or Professional Engineer. Below the thresholds, CORENET X accepts non-BIM submissions, and projects on the Direct Submission Process submit 2D plans.
Common BIM software
Three authoring tools cover most Singapore projects. Autodesk Revit is widely used across architecture, structure and building services. Graphisoft Archicad is suited to architecture-led work, with strong IFC workflow support. Trimble Tekla Structures is the structural and steel detailing tool, aimed at engineers, detailers and fabricators.
For CORENET X work, BCA's IFC+SG Knowledge Hub gives setup and modelling guidance for six tools: Revit, Archicad, Tekla, OpenBuildings Designer, BricsCAD BIM and SketchUp, the last marked as recommended for small-scale projects. The hub describes what each tool does; it does not certify or approve any of them, so treat a claim that software is "BCA-approved" with caution. The format that matters is the IFC+SG file the tool exports, and what the Model Checker makes of it.
BIM for existing buildings: scan-to-BIM
Most of Singapore's building stock predates BIM. When an existing building needs a model, for an A&A project, a fit-out coordinated against existing structure, or a facilities system, the geometry has to come from the building as it stands. Old drawings help, but they record what was designed and approved, not what was built or what has changed since.
The usual route is scan-to-BIM:
- Capture. The building is surveyed with 3D laser scanning, producing a registered point cloud: millions of measured points in one coordinate system. Our guide to what a point cloud is covers formats and accuracy.
- Scope. Elements, LOD per element or system, accuracy, software version and the target coordinate system are agreed before modelling starts.
- Modelling. Walls, slabs, columns, beams, openings and, where in scope, visible services are modelled in Revit against the point cloud.
- Checking and handover. The model is checked against the cloud, then delivered as native Revit and, where needed, IFC, with the point cloud and a note of what was and was not modelled.
A scan records surfaces. Services inside walls, reinforcement inside concrete and anything above a closed ceiling cannot be measured, so they are excluded or marked as unverified. A reliable scope says so up front rather than modelling guesses.
For CORENET X, BCA specifies the deliverable and not the capture method: nothing in its Code of Practice requires a laser scan. On an A&A project, BCA's FAQ limits the existing building to model to the parts that affect the regulatory compliance of the new works, such as interfacing elements and structure, which is much less than a whole building. Both points are covered with their sources on our CORENET X page.
Volumet's part in this is the survey and the model. We scan the existing building and model it in Revit at the LOD agreed in the quote, as described on our scan-to-BIM service page, and the scan-to-BIM reference case study shows the kind of capture a BIM team models against. We are not architects or Qualified Persons, and we do not make regulatory submissions: the QP decides what the submission needs and submits it. If your own team will do the modelling and only needs the capture, our equipment line rents scanners for that, set out on the scanner rental page and in our scan-to-BIM capture guide, and in that case your team produces the model.
BIM model or 2D as-built drawings?
Owners are often quoted for a BIM model when what they need is a set of accurate drawings. The test is simple: will anyone downstream open and use the model? If not, 2D drawings are cheaper and do the job.
| Situation | What usually fits | Why |
|---|---|---|
| Major A&A with new GFA of 5,000m² or more | IFC+SG BIM, including the existing elements that affect compliance | Required by Annex A to the July 2026 circular; the QP defines what is modelled |
| Design team already working in Revit or Archicad | A BIM model of existing conditions | The team designs directly against it instead of redrawing from 2D |
| New services or structure to coordinate against existing structure | A BIM model of the affected zones | Clash checking needs 3D geometry; 2D sections leave gaps |
| Facilities management or an asset register | A BIM model with the agreed data populated | Only worth it if the receiving system will read the data |
| Interior fit-out, lease plans, a change of use application | 2D as-built drawings | Dimensioned plans, sections and elevations are what these uses consume |
| Records of a building with missing or wrong plans | 2D as-built drawings, keeping the point cloud | A model can be built from the same scan later if a project needs one |
The last row is the practical compromise. Scanning once and producing 2D as-built documentation now keeps the measured point cloud on file, so a BIM model can be produced later from the same data without returning to site, if and when a project calls for one.
Rule of thumb: buy a BIM model when a submission, a design team or a system will use it. Otherwise, buy accurate drawings and keep the scan.