BOQ, Autoumated calculation of quantities

Hello Guys,

The calculation of the bill of quantities BOQ for a concrete structure is always annoying, since it is a repetitive logic that is applied on many different project. Having said that it is always same logic then a grasshopper algorithm can do it automatically for whatever project (with tiny modifications of course depending on the case).

For this reason, I was trying to do such algorithm.

I have extracted the structural model from Revit and imported it as solids in Rhino;

Starting with slabs, it is simple to calculate the concrete volume for every slab thickness, the formwork of the soffit of the slabs (not depending on the thickness) ..

The problem came out while calculating the formwork of the sides of the slabs:

- At come cases, the slabs are modeled as different solid elements with same thickness (as extracted from Revit) that have one or more touching faces (edges), in this case the touching edges should not be counted in the sides formwork quantities.

- At some other cases, the slabs are modeled as different solid elements with different thicknesses (as extracted from Revit) that have one or more touching faces (edges), in this case the difference between touching faces should be counted in the sides formwork quantities.

To calculate this, I want to do the following:

- Find all touching faces.

- If touching faces have same thickness then they should be removed from the calculations.

- If they have different thickness then the difference of the area should be calculated to get sides formwork quantities.

I used the solid union component, but could get results because of tree/list issues.

Can anyone help in this ?

The Grasshopper file is attached.

Thank you in advance.