Temoporary Structures, What are the rules?

Does anyone know what the rules are about what qualifies as a temporary structure? Are we limited on size? Would a straw bail building be classed as a temporary structure? Does it matter what it's built on? And are the rules different in different areas? We are looking at the La Marina area on the Costa Blanca.

 A temporary structure is anything that can be put up and taken down again. As far as I know there are no restrictions on materials.

Normally they are wooden or steel. Basically you should be able to disassemble the structure on request. So cement and bricks can't be used in the structure and the steel can not be welded etc . If the house is mobile there is no need for disassembling.  The size will depend on your local law, it depends on where you want to set up the structure. There is nothing stopping you from using a cement foundation or basement just whatever rises above the ground level should be temporary. I am asuming you are referring to putting a house on rustic land here?