Complex sentence: These rooms include the Prince's Dressing Room, the Queen's Sitting Room, the Queen's Bedroom and the children's nurseries, which were intended for private, domestic use and were therefore as comfortable as possible.
Split into simpler sentences: These rooms include the Prince's Dressing Room, the Queen's Sitting Room, the Queen's Bedroom, and the children's nurseries. These were intended for private, domestic use and were therefore made as comfortable as possible.