Complex sentence: The Masonic Hall had not only housed the Loyal Monmouth Lodge; for ten years, it had also served as the home of the caretaker, who had been away on holiday when the fire started.
Split into simpler sentences: The Masonic Hall had not only housed the Loyal Monmouth Lodge. For ten years, it had also served as the home of the caretaker, who had been away on holiday when the fire started.