How much should one intervene in a heritage structure? Is it possible for a building to retain its antiquarian roots and yet be a site of exploration for contemporary formal explorations?

How much should one intervene in a heritage structure? Is it possible for a building to retain its antiquarian roots and yet be a site of exploration for contemporary formal explorations?

Could a building be both Figure as well as Ground ? Can it be two-faced,and respond to two contexts and divergent requirements ?