As my car winds its way up a spectacular alley of towering poplars, the TarraWarra Museum of Art gradually comes into view, its rammed earth facade seeming to erupt from a hilltop in the Yarra Valley. Monumental yet humble, it was designed by architect Allan Powell in the early 2000s for billionaire philanthropists Eva and Marc Besen, to house the couple’s collection of important Australian artworks from the 1930s onwards.

When looking for words to describe the landmark, Melbourne-based architect Kerstin Thompson settles on “enigmatic”. She is the design mind behind a recently completed companion building that will simultaneously store and showcase a significant expansion of this singular collection.