Complex sentence: A large group of artists participated in the extensive decoration of both the exterior and the interior of the building which was intended to serve as a practical, modern and functional office and also refer to the rich maritime tradition of the Netherlands.
Split into simpler sentences: A large group of artists participated in the extensive decoration of both the exterior and the interior of the building. It was intended to serve as a practical, modern and functional office and also refer to the rich maritime tradition of the Netherlands.