Creating Revit Families - Key Concepts
Concepts
Creating a Family from scratch can be daunting the first few times. Because you are attempting to create and use parameters that will allow multiple Types of each family when working in a project it's necessary to:
- set up the geometry in terms of reference planes
- apply dimensions between reference planes
- create the parameters that you will later "flex" to create your types
- apply those parameters to the dimensions
- Create the bounds of your element, for simple objects often using the extrusion tool
- constrain (lock) the boundaries of your object to those reference planes
- If you're extruding a prismatic element you'll constrain the boundaries in two steps
- the prism while you're sketching it
- The height after you've extruded it
- If you're extruding a prismatic element you'll constrain the boundaries in two steps
Be prepared to make several mistakes. Starting with a really simple object such as a cube can save a lot of time.
A good example of this in process is this 2013 video of creating a bookcase. Hopefully keeping these steps in mind will help you understand this fast paced video.
A few practical notes:
- Revit has made it easy to start by providing many family templates - using one is usually the first step
- The furniture family, for instance, identifies the object as furniture and provides four prepared views (WT to see them)
- When dimensioning something like the height, work to the reference plane
- e.g. in elevation make your first click on the reference plane at the top of the object and your second on the floor reference
- If you go the other way your object will flex in the wrong manner - eg. the bottom will come off the floor.
- Not all parameters can appear in schedules. There are two types available.
- Family Parameters (the ones used in the video) are not able to appear in a schedule
- The dimension in the furniture family of the video, for example, cannot be seen in a schedule
- If you check the properties of furniture families built into Revit you'll see that dimensions are not properties
- The dimension in the furniture family of the video, for example, cannot be seen in a schedule
- Shared Parameters can appear in a schedule
- They are more complex to create and use because they reference an external text file (one per project)
- Family Parameters (the ones used in the video) are not able to appear in a schedule