Complex sentence: A further area for new building lies at the extreme Eastern end, near to the Küppersmühle, which itself has plans for extension, following the need for more space due to the fusion of the Grothe und Strцher collections.
Split into simpler sentences: A further area for a new building lies at the further end, near to the Küppersmühle. The Museum Küppersmühle has extension plans, following the need for more space due to the fusion of the Grothe und Strцher collections.