For All the Talk of BIM

For all the wonders and benefits of Building Information Modeling (BIM) it still takes a bit of problem solving, experience and knowledge to navigate.

It’s one thing being able to extract quantities for costing from a 3D Model but the question is; can you always trust them?

Far from being untrustworthy and unreliable, 3D models are an extremely valuable source of information and a week or so ago I was reminded of this working on an Preliminary Estimate.

The 3D model that I worked on was a revision on a previous model but the design had progressed substantially with fairly significant changes being made.

Firstly, the visualisation was a great tool which allowed the building to be reviewed from all angles and design changes were easily identified.

Quantities of roof sheeting, slab areas, and glazing areas seemed to come through well after writing a map to extract the quantities and bring these into our estimating software.

I would also like to mention some of the inconsistencies coming through the model, which by the way were definitely to be expected as the design was at an early Level of Development (LOD).

This is why experience, problem solving and knowledge come into play.

Some of the interesting things in the model were:

  • Additional objects that were not required were included in the model either as space savers or indications of what might be done
  • Some objects were modeled without parameters such as length or area
  • And some areas such as suspended slabs were modelled as roofs.

One of the ways around this at this early stage was that the model actually contained 2D drawings.

With a bit of navigation, thanks to a Revit Course I recently did, I was able to export additional plans and information for 2D measures. This helped give indications of wall types, soffit areas and to help with Bulk Quantity Checks.

The process of having a 3D model coupled with the wisdom of our Senior Partners allowed for faster revision of an estimate and importantly for the client, greater cost certainty.