My cat is 16 she now urinates on carpet and anything that may be laying on the floor how do I stop this?

I have taken her to the vet and they checked her out and said she was healthy I even got the aromatherapy that makes them more comfortable I have to move and its to a place with carpet should I keep her in the garage and leave the door slightly open so she can go in and out or do you have other recommendations I do not want to give her up over this