Obviously this varies from house to house, as each owner has his/her own idea of what makes a holiday home comfortable. However every property has:
(i) a fridge, a cooker or rings (we state if there is no oven), adequate cooking equipment, crockery, cutlery for the maximum number. You will not usually find a teapot or kettle.
(ii) stoves: some properties have solid stoves as well as another cooker/hob. These are normally for out-of-season use only.
(iii) bedding (usually blankets rather than duvets); sheets and pillowcases, unless otherwise stated.
(iv) some towels, teatowels, unless otherwise stated, but not beach towels and probably not enough large towels for the full number of people per property.
(v) many of the properties have automatic washing machines (detailed in house descriptions); these do an adequate job but are not generally as efficient, especially at spinning, as machines used in Britain.
(iv) properties in Cantabria, Asturias, Galicia and Portugal have barbecues, except where there is no area suitable for barbecuing.
NB. If something you feel is essential is not supplied, ask the owner. But please remember, this is rural Spain -you cannot expect to find everything exactly as you would at home. (We personally always take our own sharp knife, a tin opener, cork screw and pepper grinder on any holiday). And do take a phrase book or dictionary if you don't speak Spanish, as the owner may well speak no English.