Complex sentence: The rapid development of the city at this time meant that the Ratusz had to accommodate further administrative functions, and during the 17th century, the allocation of space within the building had to be changed to ensure that all the offices could be housed there.
Split into simpler sentences: The rapid development of the city at this time meant that the Ratusz had to accommodate further administrative functions. During the 17th century, the allocation of space within the building had to be changed to ensure that all the offices could be housed there.