Much like AutoCAD and Photoshop, Layers in FormIt allow you to manage the visibility of objects in your scene. We are going to create a layer to save and hide the building mass for analysis in the future.
Go to the Layers Palette and click the + sign three times to create three layers
Double click the layer names to rename them Massing, Floor 1, and Plan Image
Select the main building group and choose the Massing layer from the Selection On: drop-down at the top of the Layers tab.
Single-click to select the plan image group and put it on the Plan Image layer.
Select the main building group again
Press Ctrl + C to copy, and then Ctrl + Shift + V to paste the mass in the same place.
The new copy is still selected. Right-click and choose Make Unique (MU).
Note: The new Group is now severed from the original. The new group and the original group will no longer update each other.
Single-click to select either of the main building groups.
Put the group on the Floor 1 layer using the Selection On drop-down in the Layers panel.
Uncheck the Massing layer to hide it to keep it safe from any accidental edits.
Double-click the Floor 1 Group to edit it. Re-name the group Floor in the Properties palette.
Single-click the top face to select it. Click again to start dragging the face down, and start typing 1', and a dimension box will appear. Hit OK when you've entered the value. The resulting floor should be 1' thick.
Double-click off in space to exit the group.