Some time ago, I had the opportunity to talk to a Lead Contractor regarding their usage of Navisworks within a construction environment, where he has 90 Construction Managers working under him.
They used Revit models to great effect for visualization and to some extent quantification and wielded Navisworks expertly within their realm of responsibility. They also highlighted one important fact: the models that reach them from upstream are not modelled as they would prefer.
For instance, foundations are not modelled as one would construct them: They don’t pour entire foundations for the building in one day. Instead, it is done to schedule and so that various parts of the building might be started on at once, eventually culminating in an integrated whole.
Similarly, columns on many of the models spanned multi-levels. They would not construct like that either, instead building the columns level by level.
Walls were very long, and then columns would be placed in them and join geometry used to display them correctly.
They would prefer them to be drawn from an individual column to an individual column.
Roofs are not floors! Why model a roof as a floor? It does not schedule correctly in Revit to start with, and Quantity Take-off in Navisworks is also complicated by this practice.
And the list goes on…
The point is that their life is made difficult by two factors over which the BIM Author has some degree of control, but not all.
- Models are not authored in a way that considers the Quantity Surveyors and Lead Contractors.
- Revit does not always allow one to model with them in mind (who would draw a floor with all the expansion joints?). Hosting the rebar is already going to be a challenge.
In the case where it is not possible to model with Lead Contractors in mind, note that Revit gives the option to create parts. Parts may certainly be used to represent a floor, and a pouring schedule may be created. This may be done on the part of the original author (excuse the pun), or it may even be created in a model into which another Revit model has been linked.
The message is clear: model with downstream consumers in mind, considering each other’s workflows, and invest in the tools and expertise that will make the collaborative process a success.