A base-building BIM team and a workplace fit-out BIM team are often, in genuine practice, working at completely different paces on the same overall development, and understanding why avoids the scheduling and resourcing mismatches that arise from treating the two as a single undifferentiated workflow.
| Aspect | Base-building BIM | Interior fit-out BIM |
|---|---|---|
| Typical project timeline | Longer overall duration, following the building's full construction programme | Shorter, often compressed cycles - corporate fit-outs frequently run on aggressive occupancy deadlines |
| Design revision frequency | Lower once structural design is frozen | Higher - tenant/client-driven changes are common and expected throughout |
| Typical LOD focus | LOD 300-400 across structure, envelope, core MEP | LOD 350-400 for joinery, MEP terminal devices and ceiling coordination; LOD 200-300 for finishes |
Why Treating Them as the Same Workflow Causes Genuine Friction
A base-building BIM team's typical revision cadence and review cycle length, applied unchanged to a fast-moving fit-out project, will genuinely feel too slow for the fit-out client's expectations and pace, since fit-out clients are used to considerably faster iteration than a base-building programme's more deliberate rhythm. Fit-out BIM needs to coordinate tightly against the base-building model - ceiling voids, structural grid, core MEP risers - without being able to change those base-building elements, a genuinely different coordination direction than base-building BIM's own internal cross-discipline coordination.
A Scenario Showing Why Resourcing Mismatch Causes Occupancy Deadlines to Slip
Picture a firm resourcing its first fit-out project with a team more accustomed to base-building's slower, more sequential pace, applying that same working rhythm to a corporate fit-out with an immovable, externally imposed occupancy deadline tied to a tenant's own lease commitments. This mismatch is a genuinely common cause of fit-out projects falling behind schedule, not because the team lacks technical capability, but because the pacing and revision-cycle expectations that worked fine on base-building simply don't match what a fast-moving fit-out client's deadline actually demands.