More on Categories, Families, Types, and Instances

Domain Knowledge in BIM

Slides are made based on Autodesk BIM Curriculum, Greenwold, S., and D. Driver. (2007). Building Information Modeling with Revit Architecture: Lecture Notes, Autodesk, Inc. with additional content created by Wei Yan, Texas A&M University.

Categories: All objects in the building model are assigned a category. All doors in a project belong to the category Doors. This broad category is further broken down into families.

Families: Families are groupings of like geometry. Continuing with the door example, a single flush door belongs to a different family than a double door with glass in it because the geometry of the two types of doors is different.

Types: All design objects have a type. (A type is the same as a class.) The type defines what properties an object has, how it interacts with other objects, and how it draws itself into each different kind of representation.

Instances: An instance is simply a single object of a type in the building model.

Review: Categories, Families, Types, and Instances

Wall:

4© 2007 Autodesk

Working with Revit Elements and Families Families

Families are groups of similar elements. A family integrates elements that have the same parameters,

identical use, and similar graphical representation. Every family can contain multiple types.

1. Double glass door

2. Overhead-sectional glass door

3. Single-flush vision door

4. Single-flush door

Working with Revit Elements and Families Families

Families are groups of similar elements. A family integrates elements that have the same parameters,

identical use, and similar graphical representation. Every family can contain multiple types.

1. Double glass door

2. Overhead-sectional glass door

3. Single-flush vision door

4. Single-flush door

A door can easily be swapped for a different kind of door because they are in the same category. You cannot make a wall and then change it into a window because they are in different categories.

8© 2007 Autodesk

Working with Revit Elements and Families Family Types

Component family: A family you can load into your project or create by using templates. Reuse of family.

In-place family: A special type of component family specific to the project in which it is created and edited. Contains only a single type. No need reuse.

System family: A family that is predefined by the software. System families can be transferred between projects.

More on System Families

“If you can’t create the wall or roof you want with the explicit Wall or Roof tool, you can create your own custom-shaped walls or roofs using the Model in Place tool. This tool lets you make a 3D solid geometry of the wall that you can then assign to the Wall category and that will behave and schedule as a regular wall.

– Source: Mastering Revit Architecture 2010, by Greg Demchak, Tatjana Dzambazova, and Eddy Krygiel

System families are also used for many annotation categories, such as sections, elevations, levels, grids, text, and dimensions—they aren’t limited to model elements.

Another characteristic of system families is that you can’t save them outside of your project to a shared library as a standalone component. Even so, it’s still possible to reuse system families in other projects. To transfer system families between projects, go to the Manage tab, and from the Project Settings tab, choose Transfer Project Standards …”

Revit->Manage->Transfer Project Standards… for two projects.

Note that only non-in-place types can show in the list of types and can be transferred. Try Revit->Home->Component->Model in Place->Wall…

http://revitclinic.typepad.com/my_weblog/2009/04/inplace-family-walls.html

In Place Walls

11© 2007 Autodesk

Working with Revit Elements and Families Example of Families

Family/System Family Walls: Basic Wall

Type Exterior - Brick on CMU (Concrete Masonry Unit)

Instance Actual user-drawn wall in a project

12© 2007 Autodesk

Familiarize yourself with the default content libraries in the software.

When you modify a Revit element, save the family back to the library folder.

Avoid clicking the elements in a view so that you do not modify any element accidentally.

Move the cursor over an element to determine its family and type.

Working with Revit Elements and Families Guidelines

13© 2007 Autodesk

ReviewFamilies

You can define the parameters for system families. You can also load and create system families as separate files.

True

False

14© 2007 Autodesk

ReviewFamilies

You can define the parameters for system families. You can also load and create system families as separate files.

True

False

15© 2007 Autodesk

In a project, you have created families for doors, windows, tables, and walls. You group different elements either under one family or different families. Which of the following options are correctly grouped?

Mahogany wood tables and Oak wood tables under different families

Chairs of different sizes under one family

Walls and their dimensions under different families

Sliding windows and fixed windows under different families

Windows under one family with fixed and sliding as different types

ReviewFamily Types

16© 2007 Autodesk

In a project, you have created families for doors, windows, tables, and walls. You group different elements either under one family or different families. Which of the following options are correctly grouped?

Mahogany wood tables and Oak wood tables under different families

Chairs of different sizes under one family

Walls and their dimensions under different families

Sliding windows and fixed windows under different families

Windows under one family with fixed and sliding as different types

ReviewFamily Types

17© 2007 Autodesk

To make a new family type available across projects, you should save the family back to the library folder.

True

False

ReviewGuidelines

18© 2007 Autodesk

To make a new family type available across projects, you should save the family back to the library folder.

True

False

ReviewGuidelines

Questions?

Question:

How does Revit know that an element is a wall or a door, when both elements are of the same shape (e.g. rectangle)?

Specify What, Then Where

Workflow in BIM design proceeds as follows:

1. Specify what type of object you are about to place into the model.2. Specify all the necessary information about it so that it can be placed properly.

What that information is depends in large part on what kind of object you are placing. For a wall you must at least specify its start and end points. You will also have chosen ahead of time what kind of wall it is (partition, exterior, and so forth) and its height, but you canchange these later. This way there is no ambiguity.

Question:

How does Revit know that an element is a wall or a door, when both elements are of the same shape (e.g. rectangle)?

Specify What, Then Where

Workflow in BIM design proceeds as follows:

1. Specify what type of object you are about to place into the model.2. Specify all the necessary information about it so that it can be placed properly.

What that information is depends in large part on what kind of object you are placing. For a wall you must at least specify its start and end points. You will also have chosen ahead of time what kind of wall it is (partition, exterior, and so forth) and its height, but you canchange these later. This way there is no ambiguity.

Autodesk BIM Curriculum, Greenwold, S., and D. Driver. (2007)

Image courtesy of:Ryder Architecture Limited

Building Information Modeling

Families and Domain Knowledge

23© 2007 Autodesk

Compound walls are composed of multiple layers that provide space for structural components, underlayment, insulation, air space, membranes or moisture barriers, and finish surfaces.

Example - Compound and Vertically Compound WallsCompound Walls

24© 2007 Autodesk

Working with Compound and Vertically Compound Walls Materials Used in Compound Walls

1. 3/8” Gypsum board

2. 3 5/8” Metal stud

You can assign a different material to each layer in a compound wall.

You distinguish materials assigned to different layers by fill patterns that follow certain recognized graphic standards.

25© 2007 Autodesk

Working with Compound and Vertically Compound WallsFunctions of Compound Wall Layers

Structure (priority 1) Supports the remainder of the wall, floor, or roof.

Substrate (priority 2) Consists of materials such as plywood or gypsum board, which act as a foundation for another layer made of the same material.

Thermal/Air Layer (priority 3)

Provides insulation and prevents air penetration.

Membrane Layer Prevents water vapor penetration. The membrane layer should have zero thickness. It doesn’t need a priority.

Finish 1 (priority 4) Used as the exterior layer.

Finish 2 (priority 5) Used as the interior layer.

Layer functions follow an order of precedence. A priority 1 layer has the highest priority and can pass through low priority layers before it is joined.

The walls are almost configured properly.  However, the horizontal insulation must be moved inside of the core in order to cut through the air space that shares it’s same priority level. Remember, insulation and air space share the same function (http://www.marathondrafting.com/?p=43http://wikihelp.autodesk.com/Revit/enu/2012/Help/Revit_User's_Guide/2654-Tools_an2654/2908-Compound2908/2911-Applying2911)

Domain Knowledge in BIM Tools

Assumption here: insulation should cut through air space. Making it into Core (horizontal), this cut-through will happen automatically in Revit. Another way to do this is to lower air space priority to 4, but it breaks the rule of the same function layers have the same priority.

Core means core boundaries.