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Tag: Revit Families

  • Revit Families 302 – Naming and Grouping Parameters

    I started a post a couple weeks ago on tips for creating families in Revit but I didn’t get very far.   Our friends over at Inside the Factory are more disciplined bloggers than I and beat me to it. Erik Egbertson put together a great post of Family Editor Tips.  He talks about flexing a family, placing Constraints Consistently, not over constraining, avoiding chaining references, shortcuts to duplicating elements, shortcuts to creating dimensions, labeling shortcuts, and a couple other tips.

    Initial Setup and Naming of Family Parameters

    One thing that Eric didn’t cover in too much depth was naming and grouping of parameters.  I also use Eric’s programming syntax method for naming parameters except I usually capitalize the first letter.  It doesn’t make much difference really, I just like the look of it in my parameter list.  For example, “WindowTrimWidth” instead of “windowTrimWidth”.  Although Revit supports parameter names with spaces, I think having your parameters as one “word” makes writing formulas easier.

    The first thing I do when setting up a new family is place all of my reference planes, dimensions and parameters.  I flex the model with the reference planes and make sure it works.  If it does then I’ll start modeling the geometry.

    When I first add parameters I don’t write out the whole name for parameters that I know will involve some calculations.   Sometimes formulas can become quite complex:

    if(and(LoopOne, LoopTwo), DepthDefault, if(or(LoopOne, LoopTwo),DepthDefault- DepthBikeLoop, Diameter))

    Make one error in typing this out and you have a hard time debugging it.  I start with naming my parameters with shortened names like LO, LT, DD, etc.  This makes the structure easier to see.

    if(and(LO, LT), DD, if(or(LO, LT), DD – DBL, D))

    Once I know everything is working I rename the parameters and they are automatically updated in my formulas.

    Grouping of Family Parameters

    Currently Revit only allows us to categorize parameters in a set list.

    • Analysis Results
    • Analytical Model
    • Constraints
    • Construction
    • Dimensions
    • Electrical
    • Electrical – Lighting
    • Electrical – Loads
    • Electrical Engineering
    • Energy Analysis
    • Fire Protection
    • Graphics
    • Green Building Properties
    • Identiy Data
    • IFC Parameters
    • Layers
    • Materials and Finishes
    • Mechanical
    • Mechanical – Airflow
    • Mechanical – Loads
    • Model Properties
    • Other
    • Phasing
    • Photometrics
    • Plumbing
    • Rebar Set
    • Slab Shape Edit
    • Structural
    • Structural Analysis
    • Text
    • Title Text
    Analysis Results
    Analytical Model
    Constraints
    Construction
    Dimensions
    Electrical
    Electrical – Lighting
    Electrical – Loads
    Electrical Engineering
    Energy Analysis
    Fire Protection
    Graphics
    Green Building Properties
    Identiy Data
    IFC Parameters
    Layers
    Materials and Finishes
    Mechanical
    Mechanical – Airflow
    Mechanical – Loads
    Model Properties
    Other
    Phasing
    Photometrics
    Plumbing
    Rebar Set
    Slab Shape Edit
    Structural
    Structural Analysis
    Text
    Title Text

    I’m glad that Revit doesn’t let us customize this list, it would just complicate things even more.  Eric reminds us to “choose a pertinent parameter group for your parameters,” but what does that mean?  Really, it depends on your office.  I would recommend creating a standard.

    I discourage the use of the “Other” category because it ends up being a trash bin holding everything.  “Dimensions” is obvious, but I only put parameters in this group that are relevant to the user of the family.  I use “Analytical Model” for any behind the scenes calculations or dimensions that the user of the model doesn’t need to bother with; unit conversions, dimension calculations to keep the model from breaking, etc.  I have also seen “Model Properties” used for this.  If I have toggles for the visibility of different components I put those under “Construction“, if I have a toggle for something that is graphical only, like in an annotation family, I put that under “Graphics“.

    Tomorrow we will look at using formulas in families.

  • Revit Families 301 – The Struggle of the BIM Manager

    frustratedOkay folks, this is a 300 series course.  We’re not messing around anymore.  Families are one of the most powerful and dangerous things in Revit and I think they deserve some discussion.

    One of the greatest challenges I have as a BIM manager is the management of Revit Families.  I’ve tried a number of different approaches over the years and I have yet to find one that I like 100%.  I’ve always worked to establish a set of approved office standard families and have had an internal review and approval process.  The standard families account for probably 90% of the families needed on a standard project, the problem lies in the 10% of custom families or the 90% customization needed when we do a new building type we haven’t done before.

    In the early days I mistakenly thought that if I left modelers in the dark on how to edit families they wouldn’t do it.  I could train a couple of key people to do all the family modeling.  As you may expect, that didn’t work for long.  People didn’t want to go through the hassle of having someone else make and edit a family, especially when they are under pressure from a project manager.  They created families and edited the families themselves but because they didn’t know what they were doing they created families that couldn’t be reused without extensive reworking.  Usually they spent an extensive amount of time going in circles or not enough time to do something right the first time.  Days later when they would go to make a dimension change the family would break.

    The other strategy is train everyone on editing families and hope for the best.  This requires a lot more work for the BIM manager, training, supervision, review, etc.  However the entire staff ends up more educated and because they know the inner workings of the family they can use them more effectively in the building model.

    In general the people working on your models are intelligent, want to learn, and want to do a good job.  In the long run teaching them how to create and edit families goes a lot further and will save you time.