Is my IFC file uploaded anywhere?

No. Files are parsed entirely in your browser via web-ifc, a WebAssembly build of the open-source IFC parser. Nothing leaves your machine. The app works completely offline once loaded.

Can I use it with confidential models under NDA?

Yes. Because all processing happens in your browser and no data is ever transmitted to any server, you can safely use it with confidential project models under NDA. There is no service agreement to review with your client — no data changes hands.

Can I share the validation results with my team or client?

Yes. After running validation, click Share Report to copy a link that encodes the full Health Score and issue list directly in the URL — no file upload, no server, no account required. You can also export results as JSON, CSV, or a Validation Certificate. The IFC file itself never leaves your browser.

Yes, fully. IFC Viewer Online works on any modern browser — Chrome, Edge, Firefox, and Safari on both Mac and Windows. No plugin, no installation, no operating system restriction.

What happens if my IFC file is very large?

The app handles files up to 2 GB. Performance depends on your device — files under 200 MB load well on most modern hardware. Once parsed, geometry is cached in OPFS so every subsequent load of the same file is instant, even offline.

How does the validation work?

The validator runs 44 built-in rules in a background Web Worker so the UI stays responsive. Rules cover GUID duplicates, spatial hierarchy, orphan elements, naming conventions, missing type assignments, ISO 19650 property sets, LOD completeness, clash detection, proxy overuse, coordinate offset, storey-elevation integrity, unit consistency, and more. You can also run a buildingSMART IDS specification against the model. Every model receives a Health Score from 0 to 100. Results stream in as each rule completes.

Can I fix errors and re-export a corrected IFC?

Yes. All edits (GUID fixes, renames, property value changes) are held as non-destructive diffs with full undo/redo. Clicking Export IFC applies all diffs to the original binary in a Web Worker and downloads the corrected file — no server involved.

What IFC versions are supported?

IFC2x3, IFC4, IFC4x1, and IFC4x3. The viewer uses the open-source web-ifc parser — the same engine used by most modern BIM tools and @thatopen/components. Outdated schemas are automatically flagged by the validator.

What measurement tools are available?

You can measure lengths between any two points, areas of surfaces, volumes of enclosed elements, and individual edge lengths — all directly in the 3D viewport. Measurements persist as labelled annotations and can be exported alongside your model.

Can I load multiple IFC files at once?

Yes. Load as many IFC files as your device memory allows. Each model has independent visibility, transforms, validation, quantity takeoff, and export. Use the Scene panel to manage, reorder, or remove models at any time.

Does it work offline?

Yes, once the page is loaded. The WebAssembly parser and WebGL renderer run entirely in the browser. Parsed geometry is cached in OPFS so repeat loads are instant even without a network connection.

What are the file size limits?

There is no enforced limit — performance depends on your device. Files up to ~200 MB typically load well on modern hardware. The OPFS geometry cache means you only pay the parse cost once per file.

Is it free? Can I use it for commercial projects?

Yes, completely free. The source code is MIT-licensed. You can use the live app or fork the repository for your own projects, including commercial ones.

Does the red column prove a measured construction defect?

No. It is an intentionally shifted synthetic return cluster used to demonstrate how a spatial deviation can be communicated. A real deviation needs registered survey evidence and a documented tolerance method.

What makes this different from a construction animation?

The temporal layer remains XYZ point data with attributes and timestamps. The user can orbit, scrub, compare it with inspectable IFC objects and export an MCAP sequence.

Can the timeline represent weekly scans?

Yes. The same contract can carry individual epochs rather than 12 FPS frames. For real work, label acquisition time, registration transform, coverage and sampling consistently.

Back to the BIM & IFC blog

Digital Twins · 2026-08-27 · 9 min

4D Construction Progress: IFC + Temporal Point Cloud Demo

Scrub through structural phases, follow a lifted panel and reveal a deliberately shifted column return cluster against the IFC reference.

Actual IFC Viewer Online construction scene with phased point-cloud structure, moving lifted panel and red shifted-column deviation returns

A 4D construction view becomes useful when time reveals a decision: what exists now, what is planned next and where the observed geometry no longer agrees with the reference. A cinematic build animation answers none of those questions unless every temporal state remains anchored to inspectable project coordinates.

This browser example activates slab, column, wall and beam returns in phases. A panel moves through a lift path and, late in the sequence, one deliberately shifted column cluster turns red. The scenario is synthetic and labelled; the playback, bounded GPU update and IFC alignment are the same product path used by external temporal adapters.

Run the 4D progress example

Structural progress — IFC + temporal point cloud

Interactive 20-second sequence with roughly 41,000 visible points, phased structure, a lifted panel and a deliberate deviation cluster.

Actual product interface showing phased construction point returns and a red shifted column cluster against a translucent IFC structure — Progress timeline is running — scrub to inspect phases

Designed, observed and inferred are different layers

Layer	What it means	What it must not imply
IFC geometry	Planned reference and element identity	That the element has been installed
Temporal points	Observed or simulated spatial returns at a time	Automatic acceptance or dimensional compliance
Deviation colour	A comparison result under declared assumptions	Survey-grade accuracy without registration evidence
Timeline status	Playback position or acquisition epoch	A live connection unless a source is actually connected

Download the construction example

Open the construction IFC4 reference beside the representative construction PLY. The source generator and tests keep model dimensions, point bounds and fixed replay capacity reproducible.

How to make a real progress timeline defensible

Preserve the original scan and acquisition timestamp.
Register every epoch into one site frame using control, targets or a validated SLAM trajectory.
Record coverage and sampling so missing points are not mistaken for missing work.
Compare only the relevant IFC elements and publish the tolerance used.
Keep human review available before a status becomes an approval or payment event.

Why the bounded replay matters at a trade fair

The example peaks below a fixed 43,000-point buffer and reuses its typed arrays. That keeps the page responsive while the presenter moves the camera and scrubs the timeline. The same controls expose stable and fault-injected transport so the performance story is visible rather than hidden behind a prerecorded screen capture.

4D Construction Progress: IFC + Temporal Point Cloud Demo