4D Scheduling
BIM-linked construction schedule simulation using Synchro Pro, Primavera P6, or MS Project. We expose crane conflicts, trade stacking issues, and delivery congestion before they hit the schedule — with milestone animations for owner and stakeholder communication.
4D scheduling links your CPM schedule directly to your 3D BIM model, transforming a static Gantt chart into a visual construction simulation. At EZ-VDC, we use Synchro Pro or Fuzor along with Primavera P6 or MS Project to map schedule activities to model elements, producing animations that communicate phasing, identify sequence conflicts, and support owner approvals. We have delivered 4D models on projects ranging from $30M tenant fit-outs to $1.5B hospital campuses, always with a focus on constructability and schedule integrity.
Schedule Import & Validation
We import the master schedule from Primavera P6 or MS Project, validate activity logic, and flag gaps or dependencies that may impact 4D mapping.
Model Preparation & Zoning
The 3D model is organized into work packages and zones that align with schedule activities, using Revit sets or Navisworks selection sets.
Activity-to-Object Mapping
Schedule activities are linked to model elements in Synchro Pro, establishing appearance profiles for planned, in-progress, and completed work.
Simulation & Conflict Review
We run the 4D simulation and review for sequence conflicts, logistical issues, and critical path visualization. Multiple construction scenarios can be modeled in parallel.
Animation & Stakeholder Handoff
Final animations are rendered for owner presentations, permit submittals, and subcontractor coordination packages, with editable Synchro files for ongoing schedule updates.
What schedule format do we need to provide for 4D?
We work with Primavera P6 (.xer or .xml), Microsoft Project (.mpp), and structured spreadsheet schedules. For useful 4D, the schedule must be at activity level (Level 3 or 4) with activities mapped to physical zones. Summary-level schedules produce smooth animations that hide all real conflicts — we help you structure the WBS for 4D mapping from the start if needed.
What does a 4D simulation actually show?
The simulation shows your building construction week by week: structural elements appearing as poured or erected, envelope systems following, MEP rough-in, finishes, and site work — all driven by your actual CPM schedule. It reveals crane conflicts, trade stacking collisions, access route problems, and phasing issues months before they surface in the field.
Can the 4D model be updated as the schedule changes during construction?
Yes. Synchro Pro files are fully editable and schedule updates from P6 or MS Project can be re-imported to keep the simulation current. We typically provide the editable Synchro file at project completion so your team can maintain it, or offer ongoing update services on retainer during the construction phase.
Do you model temporary elements like cranes and formwork?
Yes. Tower cranes, mobile cranes, formwork systems, shoring, and material hoists are modeled and sequenced as part of the 4D simulation. These temporary elements are often where the most valuable conflicts appear — crane radius overlaps, formwork removal sequences, and hoisting congestion are only visible in a properly built 4D model.
How is 4D scheduling priced?
4D is typically priced as a fixed fee based on the number of model elements to be sequenced, schedule complexity, and revision cycles. A Level 3 4D on a $100M commercial project typically runs $15,000–$45,000. Ongoing update services (re-syncing the schedule as construction progresses) are available on monthly retainer.
