The first step to modeling a window is to add one to the model. To do so, select the opaque assembly (ceiling, main wall or foundation) in which it will be installed, then, click on "add window" to launch the window screen. Ensure that windows are modeled in the appropriate component, especially when the window is installed in a buffered wall section.

The window screen, as shown below, is used to enter the specifications of the window or skylight being modeled.

In the tree view, window components can be duplicated and dragged from a ceiling, wall, or door to another opaque assembly. Highlighting a window component in the tree view will display the window screen where the properties of the window are defined.