There are two types of rental contract in Spain. These are;par-temporada, a contract for short term letting ( or like a holiday letting contract) and Vivienda, a contract for long term letting ( which is more like the contract a buy to let landlord would use). The temporary contract covers most forms of holiday home rentals and anyone that wishes to occupy a property for up to a period of 12 months. The Vivenda will cover rental periods over 12 months. Short term lettings, like in most other countries offer very little protection to the tenant but rentals over 12 months in duration are subject to regulation by Spanish law.

That's what we're after, a long-term contract.
Otherwise we'd be better off buying, which we don't want to do as we have family property in Spain which will be available to us later.