You are certain to need an account with a local bank branch in Spain in order to make many of the usual payments that are part and parcel of owing property in Spain. It is highly likely that you will also need an account in Spain in order to buy a property. This is because many private vendors will only accept a bank-guaranteed cheque drawn from an account in Spain. Developers selling new properties are also starting to insist on payments being made from a local bank account as recent laws on money-laundering make accepting payments from other countries more complicated. Therefore you would be well advised to open an account in Spain in good time before you buy a property.
If you use a mortgage in Spain to finance your purchase it often makes sense to open an account with the bank that lends you the mortgage. In this case you choice of bank will be determined by the mortgage conditions you are offered. However if you do not take out a mortgage with a local bank you will need to do some research on the retail banking conditions being offered by different banks.
Retail banking services and charges vary significantly and it is important to look into these issues before you open an account and buy a property. One has to pay particular attention to the fees that different banks charge for receiving transfers from abroad and for issuing bank-guaranteed cheques, both of which can add thousands of Euros to the cost of your purchase if you are not careful. To avoid a nasty shock you need to negotiate these fees in advance with the branch where you open your account.