Design Process & Wall types

[Alex Page]

Our Architects love Revit!
As the Cad manager, I make sure that whatever software we use during the design process, it has to be intuitive for our different designers. Hence, one of the resons we moved to Revit.
But as well as the software, it also has to do with 'Best Practise' philosophies, which is why I frequently look at this great forum!.

Our Revit design process (walls in particular)

1.Our designers generally start with mass modeling and then move to generic wall types, say 100mm thick (Our ex Archicad users absolutely love this process). Note that we set the 'loc line' to be core face:Exterior.

2. We draw in the floors etc

4. later we change these wall types to be more specific, say 20mm exterior sheet cladding, 4mm air layer, 96mm stud layer and 10mm plasterboard layer - overall 130mm -we like 'round' numbers (why the 4mm air layer? so in section we have a 4mm gap between studs and cladding to show flashing etc.)
because the 'loc line' is core face exterior, our exterior cladding goes out beyond the floor slab - Great!

We love this process, does anyone else have a different philosophy regarding this? I would really like to hear from people, just so then I can setup different 'Best Practise' documents for different Project types

Also, our 4mm air layer is actually a membrane layer, but this is only allowed a 0mm thickness - why and what does one actually use this for

[beegee]

Your "Best Practice" for walls sounds good to me. If it is working well for you and your designers, stick with it.

A membrane layer will actually show a line on your wall sections.
Why only zero thickness ? Good question - I don't know.

[Scott D Davis]

Zero thickness because most membranes are measured in fractions of a millimeter, like 30 mil vapor barrier, which is actually .3mm, and we all know how Revit doesn't really care about displaying things that are less than 1mm.

[beegee]

Hmmm, yes I see that, .. but it would be more "Revit-like" to allow the user to make the decision about what thickness of membrane he may want to show rather than limiting this to <1mm ( 0 )

If its in the model and not just a 2D representation, then it needs to be adjustable I think.

It would also be good to allow the user to select the lineworkwork to be used ie heavy dashed line for example.

[sbrown]

I think typically the membrane is within the air space, and typicaly we dimension the air space and don't dimension to the membrane, so no need for a thickness. It probably had to be one way or the other, I don't think you can choose 0 thickness for any other category.

[bclarch]

If the membrane has a thickness and you dimension to the outside faces of your walls then it will affect the accuracy of your dimensions. On a large building with many walls in one dimension string it might add up to the point where it starts creating rounding errors.