The BIM Matrix (part 1)

Today I want to show an example of detailing. In VD&C, too much detailing is as useless as too little detailing. In the preliminary design phase when trying to figure out quantities, a good baseline is essential to good planing.

Now, I would like to show an example of the theory.

In the example shown below, I have modeled a space, 120 ft x 100 ft, with 3 levels and a roof.

The materials used:

• level 1 has a 12" generic concrete pad, 12000 CF
• levels 2 and 3 have a 3" LW concrete on 2" metal deck, 5000 CF per floor

The concrete quantities yield a total volumeof 22,000 CF.

The area of the slab yields a total volume of 60,000 SF, which includes the area of the concrete slab and the area of the metal decking for the 2nd and 3rd floors.

As seen in the schedule below, all the different parameters are shown (i.e. area, family and type, etc) and the total quantities of the area. What is not indicated in the schedule is a description of the slab for the 2nd and 3rd levels.

How do we make this schedule more essential or efficient? Well, let's modify the model with the following:

• add a slab edge to all floors, which will change our concrete quantities,
• see how the slab edge will change our cost for the concrete volumes,
• and customize the schedule for export to excel and make it more effective.

Let us estimate that 4000 psi concrete is at about $70.00 per cubic yard.

Because Revit families are dependable on the same type, giving our LW concrete the unit cost will change all the elements of type LW concrete. Instead, we will create calculated values and name it TOTAL COST per CY. Revit has calculated a total dollar amount of 57037 so far for our material, that is not including labor or other associated cost.

So, if you are asking yourself "how is this a BIM Matrix", well read part 2.