Do families have certain built-in shared parameters?

[ConstantineC]

I`m using Revit for a while but just today I realized I don`t understand something with the shared parameters.

When I open families that I downloaded from somewhere else, they have setup shared parameters like W, D, H, THK, etc that I can schedule but there is no shared parameter file attached.

When looking at the family, they are Shared parameters and the name  is greyed out. 

I checked my  shared parameter file, there are no W, D, H and THK parameters. I am confused.

Of course If I want to create a family  with same furniture category, I cannot add a shared parameter unless I use the external file. 

Are these parameters built in? Is there a naming convention for these or its something else I am missing?

I have also attached a family with these built in shared parameters, could someone test it out?

Thanks !

[ConstantineC]

Is it because I have downloaded them from a Google Drive server and Revit is accessing a shared parameter file over there that I was not aware of?

[GaryOrrMBI · Accepted solution]

Once a shared Parameter is added to a family it lives within that family. It will then become part of any project file that it is inserted into. They can also be brought into a project directly but, again, once imported into a project they live within that project.

If you have a project or family that has one or more shared parameters that you would like to use somewhere else then you can create a new shared parameter file, then export those project/family shared parameters into it. Once exported into a shared parameters file it can then be imported from that file into any other project or family that you want to use it in.

-G

[ConstantineC]

Thanks for explanation, very interesting! So they are kind of built in once created.. This is the first time I am noticing this. I did see that I can export that shared parameter but I did`nt know about this behaviour.

[GaryOrrMBI]

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@ConstantineC wrote:

Thanks for explanation, very interesting! So they are kind of built in once created.. This is the first time I am noticing this.

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I would be careful about using that analogy.

Built-in Parameters are just that, Built into the Revit software and the entity types that they are designed for.

Shared Parameters are created and used by the users of Revit, but they have a specific GUID Identifier that goes with them everywhere they go, that tells Revit that, regardless of what Revit file they come from, they are the same parameter being shared across multiple projects/families. Because they are the same parameter they also have the storage type in every file that they are used in. The method of sharing those parameters from one Revit file to another is via a text file called a Shared Parameter file. This also allows a user or company to create one or more shared parameter files for long term storage and easy access of those parameters across multiple files.

Then there are "local" parameters that are defined "in place" in either a Project file or a Family file. Local Parameters may have the same name but they do not have a GUID (and associated fixed definition) to tell Revit that the parameter in family 1 is the same parameter in family 2. Why does the name not count as a means to say that one parameter is the same as another? Because a local parameter can be named "Material" and actually hold a Material but another parameter in another file named "Material" could be a Text field. You could conceivably have 10 different parameters, all called "My Parameter", all within the same project (defined within a project or brought in by 10 different families) and each have a different data type. One might be a Built-in Parameter, then there could be a few shared parameters from different sources, all named the same but with different GUIDs, then even more brought in as family parameters.

So:

Built-In Parameters are built into the software.

Shared Parameters are defined by users and shared across multiple files for consistency.

Local Parameters are defined by users and intended to be used in that one place in which they are defined.

But, yes, once a Shared Parameter is added to a Project or Family, either via Project Parameters or via a loaded family, it maintains residency within that file.

-G

[Mike.FORM]

The other distinction is that shared parameters can be removed from the project. They will still remain in the shared parameter text file unless you save over that file within the shared parameter dialogue using 'create'.

Built-in Revit parameters cannot be removed.

Personally if I download a family that is using shred parameters, I review them and change them to shared parameters already in my shared parameter file that match. Then I will delete the shared parameters downloaded with the family so as to no bloat my project when the family is inserted.

Nothing worse than having multiple shared parameters all with the same name but are seen as different because their GUID is not the same.

[HVAC-Novice]

I think you should define what " local parameter is"  or better use the terms Revit uses. I'm not aware of a parameter type " local" . Do you mean family parameters?

- Revit has the hard-coded (defined by category) parameters you can't change and most can be used in schedules and tags. You can't change them from type to instant and vice versa. They are what Autodesk wanted them to be.

- Family parameters can be created, but only work within the family (no tag or scheduling)

- Shared parameters also are user-created, but " shared" to be used in tags and schedules.

- Project parameters are user-created and can apply to specific categories but only in the project

- Global parameters are relatively new and used to set one value and can override other parameters in families. 

There is better explanation and detail than mine in the help. But you always should use the terms Revit uses. 

[GaryOrrMBI]

True, however, those same documents often cause misunderstandings as well due to the duplicate usage of terms.

So I used "Local" Parameter instead of Project Parameter and Family Parameter due to the confusion often arising from the fact that a Project has settings called "Project Parameters" in which Shared Parameters and/or locally defined Project parameters can be created and assigned to element types in a project and Families have "Family Parameters" that can either be Shared Parameters or locally defined Family parameters.

I did preface that with:
"Then there are "local" parameters that are defined "in place" in either a Project file or a Family file"

But yeah, ok, I could have written that better to name the two different specific types of "locally defined" parameters. Has nothing to do with the point that I was making, but sure, I stand corrected.

Thank you so very kindly.

-G

[ConstantineC]

I used the term "built-in shared parameters" because it was something unexpected to see them without having the external .txt file of shared parameters  but "stored in" would be a better term.

Anywhere you look online in the documentation it says that shared parameters are stored in a  separate file.

So it seems its not always the case  and that is where my confusion was coming from.

I would even add that having the external txt file should be optional since its possible to use them without it.