Using the Architect's model to BEGIN my Structural model. Why is this frowned upon?

[J2KOL679947]

I know the recommended procedure......link in the Architectural model, use Copy/Monitor for grids, levels, etc., then begin the structural model.

However, this current project I'm starting soon is not a typical building. It is sports stadium with MANY buildings and retaining walls along with numerous reference planes.

Recreating all of this by starting a new structural model would take me a long time, even using the Copy/Monitor tools.
So, why can't I use the architectural model and simply change items such as walls to 'structural walls' and delete all of the architectural stuff I do not need? This would then be my structural model.
I would, of course, link in the architects model for future changes (Copy/Monitor) afterwards.

Thanks,
J

[david_peterson]

Here's the main reason I wouldn't.
In general I never trust anyone else to do my work.
If their model is off, you're model is off and your model is the back bone of the entire project, unless you just doing site stuff, then it's all relative.
I've seen how some Architects lay things out. For example, "Well this elevator pit is centered on the curtain wall mullion". My response was "That's great, is that going to be installed first? I need to know the location of the pit".
On another project with a radial grid I was told "Well at the center radius, I set the angles so all the columns are 25 feet apart". My response was "Whats the dimension at the inner radius. Please give me an angle that's accurate to 4 decimal places and make it that angle please".
I've also been told, "Well my angle precision is set to 1 degree cause that's within tolerance. I set my dimension precision to 1/4" so I don't see all those 1/8 and 1/16" dims when dimensioning face of wall".
Also when someone looks to point the figure cause something doesn't work out right cause it was cheated, you're not going to be able to say "Well I was just using what I got". I don't think that one holds up in court anymore.
Just my thoughts.

[DaveP]

Another big reason is that you've (presumably) got all of your company's standards built in to your Revit Template.
If you start with their model, you'll have to reload or reset everything to your standards and Import all of your families.

I'm not really even sure what else will be different if you start with an Architectural Template as opposed to a Structural, but I know Structural Columns tend to go from the Floor down while Architectural goes up.

[MikeJarosz]

My response was "That's great, is that going to be installed first?

I say this all the time.

Also, my mantra is "dimension from structure". The column lines are sacred. In fact on my current job, the column lines are checked out by me and I do not relinquish them when I save. I inform my team that dimensioning is not the same as measuring. You have to think of the construction sequence. A dimension tells where to place something, off an object that is already in place. The column lines are always in place. The construction surveyor can tell you at any time where they are, even during excavation.

[J2KOL679947]

Thanks for the replies.

So far I'm not seeing you guys list any major reasons as to why beginning with the Architect's model is bad.

The project is very early on. The levels have been established, but not the grids. I will do that shortly after beginning, although the grids will be few since it's mostly block walls and bar joists without many columns.

Also, this is our first Revit job, so we have little in the way of company standards and templates.

[MikeJarosz]

I have done some projects that had no grid. We had concrete columns scattered around and we gave them x,y coords off the project benchmark. The benchmark, chosen by our surveyor, was a dimple on a fire hyrant across the street from our site!

[Craig_L]

All of the reasons the guys listed might not seem like major reasons...until you trip on one of them and have to find where the problem comes from.
When you have set something up you will know exactly where to find an error. I rarely rely on the architect because (no offence guys) their designs are often fickle.
What I mean by that is that the Architect is not a structural engineer. They have training on general principles but often the engineer will make major changes to column layouts and load bearing wall locations - and also the Architect is often changing their model to the clients wishes which may not necessarily be buildable - an architect model for approval might be significantly different to the actual building at later phases simply due to government restrictions or clients wishes.

If you are going to be working in complete isolation from the architect then - well I guess its an option, its not a great one...
A much better option is copy monitor - this is much quicker than modelling from scratch and less likely to cause you issues later - the end result is essentially the same but it eliminates some of the other issues that were raised above (such as your company templates and you taking ownership of your companies responsabilities.)
You can make your life easier by creating view filters and templates that isolate structural elements to copy/monitor - in addition you then have the option of coordinating the models using revit tools at later dates - for a complicated stadium type project this seems like a pretty darn good idea. At some point later in the process, you should be negotiation with the architect to lose control of the structural elements and to copy/monitor yours in their place. This gives your discipline control of those elements, which is important because you are ultimately responsible for them.

[tkunsman]

I guess for your first Revit project this might not be a bad way to go. Does the architect know you are using their model to start your model with? Some other thoughts: If something goes wrong, how do you know it wasn't something they did versus what you did? This isn't AutoCAD - you need to trow EVERYTHING you ever learnt in AutoCAD out the window. You are not simply adding in some lines to represent framing or foundations.

Some other reasons include some that David already touched on, inserting your elements, setting lineweights, linetypes, etc.

How are you resolving elements that you don't want? Are you simply deleting them? I go back to does the architect know you are using HIS model?

Pride might be a good reason to start on your own instead of relying on what others have set up. You are charging money for your service are you not?

As for major reasons, I think having a few users give you some reasons might be reason enough - it is difficult to determine what you think is major and what others see as major

Since the project has block walls and bar joists, did the architect make the bearing walls "structural"?

I do hope you and your firm does implement a company template file as that is really the way to go.