IFC+SG is Singapore's regulatory extension of the openBIM IFC standard, and the required format for BIM submissions through CORENET X. A model is needed where a new erection or major A&A creates new GFA of 5,000m² or more.
One naming point first, because it causes needless confusion. IFC+SG with a plus sign is the current official styling and is what BCA and URA use in circular prose. IFC-SG with a hyphen is the older form; it still appears in BCA's own URL paths, in the 2025 factsheet footnotes and in older briefing decks. No formal rename was ever announced and neither form is wrong. This page uses IFC+SG throughout.
What IFC+SG is, and what it is not
BCA and URA define it in a footnote to the July 2026 circular: "Industry Foundation Classes (IFC) is an international openBIM standard developed by buildingSMART International (bSI) to facilitate interoperability in the building and construction industry. IFC+SG is an extension of this openBIM standard that is developed to cater to local regulatory requirements." The September 2025 circular adds the formal reference, noting IFC "is also an ISO 16739-1:2018 standard", and describes IFC+SG as "an addition to the international Open BIM standard to cater for local regulatory needs". The operative rule: all BIM submissions made through CORENET X "are required to adopt openBIM standard, Industry Foundation Classes with SG local addition" to cater for local regulatory needs.
Read that wording literally, because it is precise. IFC+SG is BCA's local addition to an international standard. It is not a buildingSMART-certified deliverable, not a registered Model View Definition, and not published in the buildingSMART Data Dictionary, and BCA does not claim any of those. The knowledge hub's plain-language version is the most useful summary: "IFC+SG defines how BIM models are structured for CORENET X submission. It combines IFC with Singapore-specific information so agencies can read, review, and check model data."
Which schema version is supported
IFC4. The IFC+SG Knowledge Hub states IFC4 is the foundational schema, and the CORENET X Model Checker puts a hard boundary on it. Error IFC0000101 reads: "Only IFC4 up to IFC4 add 2 TC1 by buildingSMART are supported". IFC4 ADD2 TC1 is the version published as ISO 16739-1:2018, which reconciles the two references you will see in BCA material.
So, not IFC2x3, and not IFC4.3. The Code of Practice does mention IFC4x3, but only inside a troubleshooting entry recording a case where a "Model could export to IFC4x3 but unable to see default psets & sgpsets", with a workaround. That is a support note, not a supported schema. Set the export target in your authoring tool explicitly rather than accepting a default.
When a model is required
The trigger is new GFA of 5,000m² or more on a new erection or major A&A project. Annex A to the 23 July 2026 circular: "BIM submissions in IFC+SG format are mandatory for new erections or major additions and alterations (A&A) projects with new GFA of 5,000m² or more." The same formulation appears in the 2023 circular, so this test has been stable.
This is not the same test as the CORENET X submission mandate, which from 1 October 2026 catches projects at GFA ≥ 5,000m² and measures major A&A by affected or replaced GFA. The two thresholds share a number but not a measure, and no official source reconciles them. The scope question is set out in full on the CORENET X page. Where a model is not required, the route is 2D: Direct Submission Process projects merge structural plans into "a single pdf or lightweight dwf file", and the Code of Practice confirms that "Besides BIM submissions in the IFC+SG format, CORENET X will be able to accept non-BIM submissions."
What the Singapore additions actually add
The SG layer takes the form of SGPsets, described on the knowledge hub as Singapore-specific property sets used for CORENET X submission, which store the regulatory information required in IFC+SG. They sit alongside the standard buildingSMART property sets rather than replacing them:
| Standard IFC property set | Singapore addition |
|---|---|
| Pset_WallCommon | SGPset_Wall |
| Pset_DoorCommon | SGPset_Door |
| Pset_SpaceCommon | SGPset_Space |
The spatial structure is the standard IFC hierarchy, and it has to be right for the model to be readable: IfcProject (overall project container), IfcSite (development or project site), IfcBuilding (building, block or building grouping), IfcBuildingStorey (level or storey where elements are placed) and IfcSpace (room, unit or defined spatial area).
Be careful with parameter counts circulating online. BCA publishes an IFC+SG Excel Mapping File, but its own documentation describes it as "a subset of the full IFC+SG mapping" and as work in progress that is "not finalised". No official total number of IFC+SG parameters is published, and no official breakdown says which agency owns which SGPset. Third-party figures are not reproducible from the mapping file. Work from the official data structure page rather than from a count.
Authoring tools BCA lists
The IFC+SG Knowledge Hub publishes per-tool setup and modelling guidance for six authoring tools: Revit, Archicad, Tekla, OpenBuildings Designer, BricsCAD BIM and SketchUp. SketchUp carries the qualifier "Recommended for small-scale projects". Vectorworks is not on the list.
Three things the hub deliberately does not say. It gives no version numbers, no plugin requirements, and no certification status. There is no BCA certification or conformance programme for BIM authoring software, so no tool is "BCA-approved" or "BCA-certified" for IFC+SG, whatever a vendor may claim. In practice Revit is the privileged path: BCA's training listing names four IFC+SG training providers for Revit, against two for Bentley and one each for Tekla and ArchiCAD.
On training and funding, the detail is easy to get wrong. BCA Academy has no IFC course of its own, and appears in BCA's listing only against the CORENET X Regulatory Approval for Building Works course. The IFC+SG training BCA points to is delivered by nine other providers, which BCA calls "training providers" rather than approved or appointed ones. BCA's Productivity Solutions Grant funds the purchase of BIM software, not course fees; course fees are subsidised separately through SkillsFuture and SSG. BCA's own circular is internally inconsistent on this point, and Annex B is the reading to follow. Current course listings are at go.gov.sg/cxtraining.
Validation: the CORENET X Model Checker
The Model Checker, published in June 2026, is a rules-based engine that "allows the Industry to validate BIM models for quality and regulatory compliance before actual submission", and whose results agency processing officers review before issuing response letters. It is an explicit beta, released as a minimum viable product, and it runs at two moments: voluntarily as a Pre-Submission Check, and automatically when you upload a model during a formal submission.
Three checks are defined:
- IFC Schema Check. Catches models failing basic IFC standards: "Outdated IFC schema versions" and "Corrupted files". It runs automatically on upload, and passing it lets you preview the model in the portal viewer.
- Quality Check. Compliance with the Code of Practice: missing mandatory properties, geo-location misalignment and similar. This is what the current MVP delivers.
- Regulatory Compliance Check. Agency requirements such as insufficient headroom clearance or undersized parking. This is not in the current MVP and is being expanded progressively.
The six published Quality Check rules are the most concrete thing to model against:
| Rule | What it checks |
|---|---|
| QC01 | Storey naming |
| QC02 | Clash detection |
| QC03 | Code of Practice modelling inputs |
| QC04 | Room tagging completeness |
| QC05 | Model coordinate alignment |
| QC06 | Level consistency |
Two limits to hold on to. The pre-submission check is recommended, not mandatory: BCA's wording is that QPs "should conduct at least one round of Pre-Submission Check" to reduce resubmissions and agency queries. And BCA states the tool "is not intended to replace QP's review". Passing the checker is not a compliance certificate. Results come back as a BCF file, and Written Directions for BIM submissions likewise "include a BIM Collaboration Format (BCF) zip files".
What commonly fails
BCA's published observations from live CORENET X projects are specific, and almost all of them are set-up failures rather than modelling failures:
- "Lack of Coordination in Initial Setup: Fails to establish and document agreed-upon coordinate settings during project kick-off leads to models being created with different reference points and orientations, causing significant coordination issues downstream."
- "Poor Communication of Reference Point Changes", leaving teams working to outdated coordinates and producing misaligned models.
- "Federation issues e.g. building elements (e.g. drains) to appear 'floating' and disjointed tower block and podium".
- "Models submitted with missing files result in incomplete elements (e.g. roof)".
- "Skipped model checks before submission. Project teams who skip quality checks often submit models with obvious issues."
- "Lack of clarity in correspondence. Generic replies such as 'complied with' or 'noted' are insufficient and may lead to additional queries."
- Digital signing: "Long filepath. File located in multiple levels of sub-folders may cause error during encryption."
BCA's corresponding recommendations are equally plain: "Establish a common project reference point at project start, ensuring all discipline models align within the same coordinate system for accurate federation"; notify all BIM teams immediately if the reference point changes; define and maintain a centralised standard for storey naming and height; and upload models early to use the "Preview Model" feature "to ensure models are geo-referenced and coordinated accurately prior to submission". The December 2025 Good Practices Guidebook is the current published home for this material.
Getting to a model when the building has none
A&A projects are where this bites. The Code of Practice confirms that A&A and Conservation models carry "New", "Existing" and "Removed" element statuses, held as IFC+SG parameters rather than as drawing colours, so existing fabric appears inside the model. How much of it? BCA's CORENET X FAQ is narrower than most vendor claims: "Only existing development that affect the regulatory compliance of the new extension in the A&A project will need to be modelled (e.g. interfacing building elements and structure)." Scope the capture to that, not to the whole building.
Conservation is the exception where a document of the existing building is named outright. The Code of Practice lists "(For non-BIM submission) Measured survey drawing (for unrestored building)" or "(For BIM submissions) BIM model of existing building for unrestored building". Two qualifiers ship with that: conservation projects "are in the exploratory phase of CORENET X submissions and do not need to be submitted in IFC+SG", and URA separately requires Measured Survey Drawings with a registered Surveyor's endorsement, a statutory role that a scanning or modelling contractor does not hold and that Volumet does not claim.
On method, BCA says nothing at all. A full-text search of Code of Practice Edition 3.1 returns no occurrence of point cloud, laser scan, Scan-to-BIM, reality capture or photogrammetry, and none appears on the knowledge hub. BCA specifies the deliverable and never the capture route, and publishes no LOD grade and no accuracy tolerance: the rule is that BIM components "do not need to replicate their real-life equivalent" as long as IFC+SG data and minimum dimensions are present. Correctness here is dimensional and data-level, not visual.
A measured scan is therefore one route to that geometry, not a required one. It does align well with what the Quality Check tests, since a georeferenced capture fixes a single coordinate system, real storey heights and levels that agree with each other. Our Scan-to-BIM service takes that from capture to a modelled, parameterised deliverable, and you can tell us the building and the gateway you are preparing for to get a scope.