05 - Viewing attributes and properties

You can view the Attributes, Properties, and Quantities of the selected object in the Object Properties tab.

Let’s focus on Attributes first. Scroll down to the IFC Attributes subpanel. Attributes are a limited set of fundamental data (usually less than 10) associated with all IFC elements. These are fixed by the IFC standard.

Here are some common attributes and what they mean:

• GlobalId: a unique ID for the element useful for computer geeks
• Nam.e: a short name, code, number, or label to identify the object for a human. If you had to annotate the object on a drawing or a schedule, the Name is what you should see. For example, a window Name might be W01.
• Description: typically the longer form of the name, written to be descriptive and readable for humans. For example a pump Description might be Water Suction Pump.
• Tag: this is an ID that may link it back to another BIM application. For example if the IFC model was produced using Revit or ArchiCAD, it might hold the Revit or ArchiCAD element ID.
• Predefined Type: A further level of classification to be read in conjunction with the IFC class.

Warning

Some IFC models have poor quality data. For example, if the Name of a Window doesn’t match the window code (e.g. W01) you see on a drawing, the project manager has clearly not put enough effort. Shame on them.

Properties are other data associated with the object. Every project will have different Properties depending on what information they want to store. Each Property has a name and a value, and are grouped into Property Sets. Each Property Set also has a name.

You can find Properties in the IFC Property Sets subpanel.

Some very common Properties are standardised by international BIM standards. For example, the load bearing Property of a beam should always be called LoadBearing. If a Property Set is part of the international standard, it has a prefix of Pset_, like Pset_BeamCommon.

If you see a Property Set without the Pset_ prefix, it is a custom property defined by the author of the IFC model.

Tip

It’s important to distinguish between Properties that are part of the standard compared to custom ones. When Properties are standardised, it makes it easy to manage data. So if you need to isolate all LoadBearing elements, you now know exactly where to look.

Quantities are very similar to properties. They also have a name and a value, and are grouped into Quantity Sets. Similarly, there are also common quantities defined as part of the international standard, denoted by the prefix Qto_. This prefix is short for “Quantity Take-Off”.

You can find Quantities in the IFC Quantity Sets subpanel.

06-Finding the location of objects

Every object in the built environment has a location in the world. For example, a chair will be located in a space, and a wall is typically located in a building storey. You’ve already seen this hierarchy of spaces in the Outliner panel, where an IFC project is broken down into site, building, storeys, and spaces.

Sometimes, objects may have multiple relevant locations, such as a multi-storey column which can be related to multiple building storeys. Even in these cases, IFC enforces one location to be its primary location, known as its Spatial Container.

If you click on any object, you can see its location in the IFC Spatial Container subpanel in the Object Properties tab.

Press the Select Icon to select all objects that are in the same location.