Revit Tutorial – Type vs Instance Parameters

Been a little while since I posted a tutorial but this month I am going ‘back to basics’ to talk about Instance and Type Parameters and where to use them. I still find that many people are using OOTB families that are not suitable for certain modelling workflows. I will focus in on two specific families, Structural Openings and Structural Framing. The structural Openings will be created with a Generic model family that’s face based, this will be ideal for rectangular openings in walls, foundations, floors, beams etc. Let’s start by looking at the instance properties of Structural Framing. In the image below I have selected the UB section, notice that the Structural Material is instance based.

Revit 2020 - Structural Framing Instance Parameters

It may be more relevant if we made this a type parameter as the structural material needs only to be set once per family type. To do this you can simply edit the family and change the instance parameter to a type parameter. With the Structural Framing Element selected, click the Edit Family button on the Modify | Structural Framing context ribbon.

Revit Edit Structural Framing Family

The Structural Framing element will now be open in the family editor. Select the Family Type button as shown in the image below.

Revit Family Types

You will now see the Family Types Dialog box displayed. Note that the Structural Material is shown. An instance parameter will always have the bracketed word (default) displayed. This is the easiest method to spot the instance parameters.

Revit - Structural Framing Material Edit

Select the Structural Material parameter and then select the Edit Parameter command by selecting the pencil icon in the lower left of the dialog box as shown below.

Revit Family Types Dialog Box

You will now see the Parameter Properties Dialog box as shown below. Select the Type Parameter radio button as shown below and then click OK.

Revit Parameter Properties Dialog

Click OK to the Family Types Dialog box, note that the Structural Material Parameter has the (default) removed as this is now a type parameter.

You can then save the family and set the type parameter. This will then update all members of the same family type.

A full video tutorial is available here, the video also covers the creation and use of structural opening family.

Revit Structure Tutorial – Structural Opening Families

Many of you will be using the Shaft Opening command within Revit to produce vertical openings within your models. Whilst being fairy efficient they have the following limitations:

  • Can Only be used to cut vertically
  • Can only cut floors
  • Analytical model cannot be adjusted

Perhaps the biggest issue here is the results on the analytical model and the fact that this analytical model cannot be adjusted. This can result in gaps from the floor slab to a structural wall as shown below. I would suggest that you set the analytical model of walls to the outside faces which will eliminate the gap.

Gap in Analysis model

To solve the other issues of placement I have created a tutorial video which explains how to create your own structural opening family with step by step instructions which can be viewed here.

http://youtu.be/xQuQLl0K310

We start by creating a Metric Generic model.rfa family template to develop the mail opening.

File - New - Family

  1. Create the parametric framework by using for Reference Lines to control the length and width of our opening. On the Create Ribbon click the Reference Line command and create the four Reference lines as shown below. The Reference Lines enable the shape handles to be displayed in a 3D view.

Opening Symbol - Reference Lines

2. Next you add two parameters to control the opening length and width. Create an Aligned dimension for the length and width and add the parameter as shown below.

Add Parameter

3. In the Parameter properties  box make sure that you select the Instance radio button to enable the shape handles and allow individual control of each structural opening.

Add Parameter Dialog Box

4. Repeat this for the Opening Width parameter. Your family should now look similar to the image below.

Opening Symbol - Reference Lines

Next you create the void extrusion. On the Create Ribbon click the Void Extrusion command as shown below.

Void Extrusion

Sketch a Rectangle and lock all four padlocks to ensure that the geometry is constrained to the Reference Lines as shown below.

Rectangle Constrained

Click the green tick to finish the void extrusion. In the Project Browser switch to the front view and align the top and bottom of the Void Extrusion to the Reference Lines as shown below. You will also need to create a parameter for the opening height; this will also be an instance parameter.

Constri

5. Next you configure the Family Categories & Parameters, on the Create Ribbon click the Family Categories & Parameters command. To ensure that you can use the void extrusion in any plane you select the Work Plane-Based option. The void will not be able to cut families unless the Cut with voids when loaded option is switched on. Lastly you can uncheck the Always vertical command to enable the family to be placed on any plane.

Family Categories & Parameters

The main part of the structural opening is now complete; you will now need to create a 2D opening symbol that will appear on each section or elevation that projects the opening. Save your Family as Structural Opening.rfa. Do not close the file as you will load your 2D detail into this family in later steps.

2D opening Symbol

6. We start by creating a Metric Detail Item.rfa family template to develop the 2D opening detail.

File - New - Family

7. Create the four Reference Planes as shown below. I have mirrored the reference planes to initially make the planes symmetrical.

Reference Planes

8. Next you create two Aligned Dimensions and then add instance parameters to control the 2D detail called ‘Opening Length’ and ‘Opening Width’. Both of these parameters need to be instance parameters. Your family should now look similar to the image below.

Opening Length and Width Parameters

Next you create a sub category to allow control of line weight and visibility. On the Manage Ribbon click the Object Styles command.

Object Styles Icon

In the Object Style dialog box create a new Subcategory named ‘Structural Opening Symbols’ and click Ok on both dialog boxes.

Object Style Dialog Box

9. On the create ribbon click the Line command to start the place line mode.

Detail Line Icon

Draw the two diagonal Detail Lines as shown in the image below and ensure that the Structural opening sub category is selected. There is no need to lock the detail lines to the Reference Planes as Revit will assume that the lines should be constrained to the Reference Planes.

Strcutural Opening Sub Category

Flex the family by selecting the Family Types command on the Create Ribbon to check that the Detail Lines respond to the changes. Save the Detail Component as 2D Structural Opening Symbol.rfa.

10. Next you load your 2D Structural Opening Symbol into your Structural Opening.rfa. On the Create Ribbon click the Load into Project command as shown below.

Load into project Command

If the Load into Projects Dialog box shows then ensure that you select the Structural Opening.rfa. Depending on your last view you may get a warning, you can ignore this.

11. In the Project Browser make the Floor Plans, Ref.Level view active. On the Annotate Ribbon Click the Detail Component tool as shown below.

Detail Component Button

You should now be able to place your 2D Structural Opening Symbol onto the active view. Make sure that you lock the 2D Detail to the Reference Lines.

Your Family is now ready to test!

When inserting the family into a project you use the Place Component command on the Structure Ribbon. It is also worth remembering that you can control the placement mode to be on a Face or on the active Work Plane. Remember that a YouTube Video is published at:

http://youtu.be/xQuQLl0K310

Place on Face or Workplane

lawrenceH

Openings through Beams in Revit Structure

I was asked last week if there is a quicker method of adding openings to beams for service voids. I have been asked this question a few times in the past and thought I might have a look at possible methods to speed up this process.

I came up with the idea of using a beam as a void opening. The advantage of this method is that you can cut through many beams and very quickly align this to duct runs and change levels etc. I used a CHS section and moved the swept solid onto a sub category called void openings. This allows me to switch this off in the view templates. Once this is completed then you can draw a beam in the normal way and then use the notching tool to create the voids. You can set the notching distance to the clearance you require and if the beam moves it will automatically update the notches. Another good use if to reference the MEP model into Revit Structure and then simply align the beams to the ducts, pipes etc.

If the model is going out for analysis then you just need to make sure that the beams used as void formers are set ‘Not for Analysis’.

It’s not a perfect solution but at least speeds up the process!

LawrenceH