What is the fine-grained topic of the following text: The architect, whose Hackney Empire renovation has also helped transform another revered east London entertainment institution, recognises the weight of this cultural responsibility by crafting an exceptional artistic and environmental response that not only restores the historic fabric to its magnificent original state but imbues it with an innovative array of sustainability features that will help ensure its survival in perpetuity. Only return the topic.
Architect's renovation of Hackney Empire with sustainability features.