The importance of having a safe and calm environment cannot be overemphasized for pet cats. This is the time where they are most vulnerable. That is why litter boxes placed on dead end areas or areas with only one way in and out are perceived as traps for cats and thus will not be used.
There should be a litter boxes available on each level of the house where the cat can have access to it. Do not place food and water near the litter boxes as cats do not like to eat or drink in the same place where they eliminate. Avoid loud areas as noises can frighten cats.