not 100% sure of the spanish laws, but if it is through a tour operater that your going through, i would assume they vet the hotel/aparments (or should do) before taking up a contract for holidy makers ect.... to stay, as if anything does happen the tour op could face charges and big compensation claims, or even worse like the thompson reps with them poor family who died of carbon dioxide

All TO's have to adhere to a health and safety code of conduct for their clients. Clear patio doors should always have stickers on them to highlight the dangers of transparent glass.