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A 4D model plays the construction programme on the 3D model: each activity makes its elements appear in sequence. Watching it, people spot what a bar chart hides. But 4D is fragile unless the programme and the model are built on the same breakdown, and linked by rules.
- 1Agree the breakdownLevels, zones, pours and work packages
- 2Code the programmeEach activity gets a code: L03-Z1-FRAME
- 3Code the modelElements carry level, zone and package properties
- 4Link by rulesActivity ↔ elements with matching codes
- 5Play and checkLogic, workspaces, logistics, every update
Share the breakdown
The planner splits the job into activities by location and work type. The model has to be split the same way, and its elements have to say where they belong.
| Breakdown | Example values | Lives in |
|---|---|---|
| Level | B1, 00, 01, 02… | Programme activity code; element Level property |
| Zone | ZA, ZB, ZC | Activity code; element Zone property |
| Pour or lift | P1, P2 | Slab and wall elements split by pour |
| Work package | FRAME, SLAB, ENV, MEP1 | Activity code; element Package property |
A location breakdown structure divides the project into places: buildings, levels, zones, pours. A work breakdown structure divides it into packages of work: substructure, frame, envelope, services first fix. Combined, they name every piece of the job, like Level 3, Zone 1, Frame.
Link by rules
A rule says: activity L03-Z1-FRAME links to all elements whose Level is 03, Zone is Z1 and Package is FRAME. When a new model revision arrives, the rule finds the new elements automatically. Hand-picked links have to be redone.
What to check in 4D
- Logic: elements appearing before what supports them.
- Workspaces: two trades in the same zone at the same time.
- Logistics: cranes, hoists and laydown areas against the sequence (next lesson).
- Hidden works: services installed before the ceilings close.
The programme has four activities:
| Activity | Code |
|---|---|
| Frame Level 02 Zone A | L02-ZA-FRAME |
| Frame Level 02 Zone B | L02-ZB-FRAME |
| Slab Level 02 Zone A | L02-ZA-SLAB |
| Slab Level 02 Zone B | L02-ZB-SLAB |
The model contains:
| Elements | Level | Zone | Package |
|---|---|---|---|
| 12 columns | 02 | ZA | FRAME |
| 18 beams | 02 | ZB | FRAME |
| 6 beams | 02 | Zone A | FRAME |
| 1 slab (whole floor) | 02 | (blank) | SLAB |
- Write the rule that links each activity to its elements.
- Which elements won't link, and what would you change?
Open the 4D Simulator and click Try the sample model and programme. The programme has one activity per level, zone and package (for example L01-ZA-FRAME), and the level codes are translated from the storey names by a value map.
- How many elements link to an activity?
- Which values and codes match nothing, and what's the story behind each?
- What would you change so every element links?
Stay in the 4D Simulator with the sample loaded. The programme starts on 1 March 2027 and has progress reported to 5 April 2027 (the status date). Use Planned vs actual.
- On the status date, which activities are behind, and why is each one behind?
- The Problems panel reports one activity planned before what carries it. Click it: what is wrong, and how would you change the programme?
- Click one of the nine amber beams on the first floor (tip: choose Only 01 First floor in the levels list) and move it to L01-ZA-FRAME. What changes, and why is this only a stopgap?
Key takeaways
- Agree a location breakdown (levels, zones, pours) and work packages with the planner first.
- Put the codes on both sides: activities in the programme, properties on model elements.
- Link by rules (matching codes), never element by element, so links survive model updates.
- Use 4D to check logic, workspaces and logistics, not only to make a tender animation.
Your notes
Related tool
Play the programme on the IFC model: see it built day by day, find late work and sequence errors.
Open 4D Simulator →