In CET, you can draw custom floors and insert additional levels to handle multi-story buildings. 
In this article, we’ll cover how to create multiple floors and how to manage custom and multiple floors in the Level overview. Here’s a picture to show how the interface will look when you are working with multiple floors:

  Level categorization

When you place an object on a level, it will automatically belong to the level whose boundaries it is placed within. You can manually control this in the Level categorization dialog where you select the level(s) that you want the selected object to be assigned to. Note that unchecking the all levels will trigger the dialog to automatically reset the object to its default level(s); depending on its location.

Level overview

In CET, the default setting is to show a basic rectangular floor in the 3D view that expands automatically to accommodate all objects that are placed in your drawing. This floor is labeled Base and refers to the default floor and the space that surrounds it. It will always appear at the bottom of the Level overview and entails everything that is not specifically connected to or placed on another level.

Any time you create a custom level it will be listed in the level overview and is automatically named Level 1, 2, 3, and so on (you can change the name manually).

Let’s take a closer look at what all the icons mean:

	Show / hide level (hides the level and everything categorized to it)
	Lock / unlock level movement (the level and all items on it will not be editable)
	Solid / transparent level (physical floor of transparent level will disappear and objects underneath can be selected; all objects on level can still be seen and edited)
Level 1, 2, 3 etc.	Level name
94", 204", etc.	Level elevation from base level
(-)	Will show number of objects selected / total number of objects on level
	Add a new level on top of the selected level
	Pastes copied objects directly between levels
	Select all objects on level
	Remove level

The three icons before the name of the level are for toggling visibility, lock, and solid for all levels at once.

Selecting a level in the list will highlight the corresponding level in the drawing area and vice versa.

Editing a level

Below the level list you can adjust the level name.

Here, you will also find a button that opens the Part Tagging dialog, since tagging levels works the same way as tagging any other components. Note that when tagging a level, the tag automatically applies to all objects placed on that level as well.

There is also a button to access the Material Explorer to paint the floors and the option to save a certain material as default.

  
Edit options for additional levels

Properties for additional levels can also be controlled in the quick properties when a level is selected:

There are additional floor settings when the Base floor is selected besides the options for all other levels:

Edit options for the Base floor 

Level Buttons in the 3D View

When you are working with levels, new buttons become visible at the bottom of the 3D view beneath your View Modes. They are for toggling the level visibility, i.e. showing or hiding levels in the drawing, and to control which level is currently active.

A black border indicates your currently active level. Levels currently visible are indicated with a blue color. Left-clicking on a level button toggles the visibility, while right-clicking on a level button will change which level is currently active.

Changing the level visibility by clicking these buttons is also reflected in the Level list and vice versa.