contradiction of portable buildings

In modern architecture, the Portable Buildings  are referred to as those designed to be moved from time to time. This basically militates against the idea of a building that has permanence as its basic feature. The portable buildings have as their main feature the lack of permanent location. A modern term used to refer to portable buildings is that of a relocatable building. In modern parlance a transfer is basically relocation and the person who transports his building is in effect relocating it. A building refers to something permanent while portable refers to anything transportable. Thus a building that can be moved is a contradiction in itself.