Ok, thanks for you wise words.

Lets say I have a legal building on the farm which is about 45 sq/m, is there anyway, anything that could be build temporally using any material to accommodate additional storage?   

In England if you have been refused a permission to build an extension you can always alter the plans and try again, if this does not help you can appeal.    

In Spain you can ask for permission and if you failed then that's it, no other options?

This probably sound a little bit desperate but I do like this area very much, farm is located in fantastic area with water and is within my budged.