Viewport Scale

Double-click in the lower-right corner viewport to activate it
Zoom and pan to place the view

Set the scale to 1:50

Click Lock icon to lock the viewport prevent it being change

Pick point in lower-left viewport and make it current
Zoom and pan to the Elevator area

Set the scale to 1:50 and lock it

Pick point in top-right viewport to make it current
Zoom and pan to Printer Island area

Set the scale to 1:50 and lock it

Pick point in top-left viewport to make it current
Zoom and pan to Office area next to Printer Island

Set the scale to 1:50 and lock it

Double-click outside the viewport to return back to paper space