Hi there
I recently used the terms with reference to a historical palace and architectural descriptions. I'd leave the expression as it is and go for an effective adjective for "inedito" (my example is just an idea). I believe it's in italiacs coz it's latin but that's it - it's a common expression in Italian and in architecture.

Here's the explanation from Wikipedia:
"In Roman mythology a genius loci was the protective spirit of a place. It was often depicted as a snake. In contemporary usage, "genius loci" usually refers to a location's distinctive atmosphere, or a "spirit of place", rather than necessarily a guardian spirit.In the context of Modern architectural theory, genius loci has profound implications for place-making, falling within the philosophical branch of 'phenomenology'.