Go to the building card (see image below).

If you are not already on the tab in question, click the tab called "Supplement objects" (see the first image below). Clicking the tab called "Supplement objects" will, among other things show a button called "Add new supplement" (see the second image below).

Click the button called "Add new supplement" (see the first image below). When you click the button called "Add new supplement", a list of supplement object types will open (see the second image below).

Select the type of supplement object you wish to create. This is done by clicking a supplement object type in the list of supplement object types (see the first image below). Then finish by clicking "OK" (see the second image below). When you click "OK" in the list of supplement object types, an additional object of the type you have selected will be linked to the building you are working with. At the same time as a supplement object is linked to the building you are working with, the supplement object's object card will open (see the second image below). In the object card you will find three tabs: "General", "Properties" and "Operations". Using the object card, you can work with the settings for the supplement object you have linked to the building you are working with. Within the tab called "General" you can, among other things, name the supplement object, specify whether or not the supplement object should be shown on the map and set a map marker for the supplement object.

Close the object card (see the first image below). Closing the object card will take you back to the building card. In the building card, you will see that a supplement object of the type you selected in step 4 has been linked to the building you are working with (see the second image below).