You’re reviewing a BIM model and spot a beam clashing with a duct. How do you tell the responsible party? Paste a screenshot into an email and write “around the northeast on level 3” — a familiar scene, and a breeding ground for miscommunication. BCF exists to solve exactly this.
BCF is a “common format for issues”
BCF (BIM Collaboration Format) is an open format for exchanging issues raised against a BIM model. Like IFC, it’s defined by buildingSMART and is vendor-neutral. It’s one of the pillars of openBIM alongside IFC.
The key point: it lets you share just the issues, decoupled from the model itself, in a lightweight way. Instead of mailing a multi-hundred-MB IFC back and forth, you exchange only the “where and what is wrong” as a small file.
Why handle issues separately from the model
Verbal or email feedback has problems:
- Vague location: “northeast on level 3” means different things to different people.
- No reproducible viewpoint: the recipient can’t see the model from the same angle.
- No way to pin down the target: words alone can’t identify which element you mean.
- No history: who raised what, when, and how it was resolved is untraceable.
BCF solves these by structuring the information.
What a BCF topic contains
A single issue (topic) typically includes:
📷 Viewpoint
Camera position when raised, so the recipient opens the same angle.
🎯 Target elements
Which elements it concerns (by IFC element ID).
🖼️ Screenshot
A visual aid.
💬 Title & comments
What's wrong and how to fix it.
📌 Status & assignee
Open / in progress / resolved.
In short, BCF carries reproducible, trackable issues.
How IFC and BCF relate
They’re often confused, but their roles are distinct:
- IFC = the building data itself (geometry, properties, relationships).
- BCF = the issues, comments and tasks raised against that IFC.
If IFC is “the drawing or model,” BCF is “the sticky notes and the conversation on top of it.” Each BCF topic references IFC element IDs, preserving the link “this comment is about this column.”
How it’s used in practice
A typical workflow:
Overlay and check
Design, construction and MEP parties overlay their models and look for clashes and inconsistencies.
Raise the issue in place
When a problem is found, a BCF topic is created with a camera viewpoint and target element attached.
Share and understand
The recipient opens the model from the same angle and understands it immediately.
Fix and track
After fixing, the status is updated and tracked through to resolution.
This dramatically reduces the “he-said-she-said” and “which part are we talking about?” friction of coordination meetings.
How tools handle it
BCF can be exchanged as a file (.bcf / .bcfzip), or managed as issues inside a tool. Some web-based BIM tools let you create an issue while looking at the model and save it with a camera viewpoint for sharing (Bimly works this way — it stores a camera viewpoint with each issue and can restore that exact view from a link).
Summary
- BCF is the open format for sharing issues and tasks against a BIM model.
- It’s decoupled from the model (IFC), so issues stay lightweight, reproducible and trackable.
- It carries camera viewpoint, target elements, comments and status as structured data.
- IFC is “the building data,” BCF is “the issues about it” — complementary, not competing.
The more your team runs clash detection and design coordination on “screenshots and email,” the more there is to gain from switching to BCF-style issue management.