IFC drawings are drawings marked "Issued for Construction": the revision of the drawing set that the contractor is authorised to build from. Before that point drawings may be issued for information, for coordination, for approval or for tender, but only IFC drawings are the instruction to build. In BIM, IFC also means something entirely different: Industry Foundation Classes, the open file format (.ifc) for exchanging building models between programs. This guide covers both, because the two meanings are often confused.
IFC meaning 1: Issued for Construction
A drawing becomes IFC when the design team formally releases it for construction, usually with a status in the title block, a stamp or watermark, and a new revision code. Common conventions:
- Status in the title block: "Issued for Construction", "For Construction", or a status or suitability code where the project uses ISO 19650 naming.
- Revision code: many offices use letters during design (A, B, C) and switch to numbers at IFC (0, 1, 2), so "Rev 0" is the first construction issue.
- Transmittal: the IFC set is sent with a transmittal stating the purpose "for construction". See what is a transmittal.
Drawing issue statuses compared
| Status | Meaning | Can the contractor build from it? |
|---|---|---|
| For information (FI) | Shared so others know about it | No |
| For coordination | Shared with consultants to coordinate | No |
| For approval / for comment | Sent to the client or authority for review | No |
| For tender / for bid | Used to price the work | No |
| For construction (IFC) | Released to build | Yes |
| As-built / record | Records what was actually built | Not applicable |
What changes between tender drawings and IFC drawings?
Often more than people expect: answers to bidder questions (addenda), value engineering decisions, coordination fixes and authority comments all land between tender and IFC. Every change should be clouded and recorded in the revision block, but clouds only show what someone chose to mark. Comparing the IFC PDF against the tender PDF shows every difference. In Ncored, the PDF editor we built in our architecture studio, you open the IFC sheet and drop the tender revision onto it: added items turn blue, removed red, unchanged grey. It works on whole sets on Windows and Mac. See how to compare two PDF files.
IFC meaning 2: Industry Foundation Classes
In BIM, an IFC file is a building model saved in the open, vendor-neutral format maintained by buildingSMART International and published as ISO 16739. Revit, ArchiCAD, Tekla, Allplan and most other BIM tools export and import IFC, so a structural engineer in Tekla and an architect in ArchiCAD can exchange models without owning each other's software. An IFC file carries geometry plus data: element types, materials, property sets and classification codes.
| Issued for Construction | Industry Foundation Classes | |
|---|---|---|
| What it is | A drawing status | A file format (.ifc) |
| Used for | Authorising construction | Exchanging BIM models between programs |
| Where you see it | Title block, stamp, transmittal | File extension, BIM execution plan, EIR |
Context usually makes the meaning clear: "the IFC set" on site means drawings; "send me the IFC" from a BIM coordinator means the model file. More on BIM in what is BIM in construction.
Frequently asked questions
What does IFC mean on a drawing?
Issued for Construction: the drawing has been formally released and the contractor may build from it.
What is the difference between IFC and AFC drawings?
Both mean the drawing is released for construction. AFC stands for Approved for Construction and is used by some owners and industries instead of IFC.
Can an IFC drawing be revised?
Yes. Changes after IFC are issued as new revisions (Rev 1, Rev 2 and so on), each clouded and recorded in the revision block and sent with a transmittal.
How do I open an .ifc file?
With a BIM authoring tool such as Revit or ArchiCAD, or with a free IFC viewer. It is a model format, not a PDF, so PDF editors do not open it.
Related: the five design phases, as-built drawings, CAD vs BIM.