Yes, it sounds strange or wrong but it is not.
Let me clarify:
Spanish Law protects specially those renters of a home and try to provide permanence to them as a family; that is why these for-home-reasons rental contracts are benefitted with the right of yearly legal extension if decided by the tenant for a period of 5+3 years.
And how do I know my contract is a seasonal or a home contract?
EASY: It needs to be mentioned or infered in the text of the contract.
You can sign a contract with a rental period of 11 or even 3 months and, if you do not explicitly mention that is a SEASONAL contract, once the time period expires, your tenant will inmediately have rights for the extension of the rental contract for a year more and, what is even worse... will have this right for 5 years + 3 years.
The only way to kick the persistent tenant out would be if you or a descendant needs the house for living purposes, which will have to be proved by you.
On the other side, you can sign a contract for 2 years and being stated is a SEASONAL contract, once the 2 years period is over, the contract obligations are all over.
So..... do not just look to the numbers... look to the words ( SEASONAL vs HOME)
Under Spanish Law, what makes a contrat a seasonal or a permanent home contract is not the time agreed but the intention. There is a widespread misconception about this as it is assumed that a rental contract with a time period under 12 months is a seasonal contract and therefore the tenant will not have legal rights to contract extensions up to a period of five + three years. IT IS WRONG.