Junya Ishigami creates art that borders on architectural, or at least, spatial. Does all sculpture/installation do this? In my opinion, not all do (a particularly awful video ensemble at St Paul's Gallery springs to mind..)
What drew my attention to Junya Ishigami is the built form at the 2008 Architectural Biennale in Venice. Titled "Extreme Nature: Landscape of Ambiguous Spaces", it resembles a greenhouse with a playfulness that defies that traditional idea of a greenhouse.
Even the plan for this installation exhibits a light hearted nature, yet 'extreme nature' is an ironic title for the planned and planted.
I always appreciate a 'usefulness' in installations. Not ones that rely on novelty; when forced, the idea or provocation is much too blunt. When you can wander into something and fit in, take in the subtlety of the moments and the design/delivery, they make the most sense. The Serpentine Pavilion by Peter Zumthor I visited in 2011 was just that, including the sense of dramatic lead up that comes with a hulking black exterior, 'inner skin' to a functional courtyard space.
That said, Ishigami has shown breadth in both functional space and statement space. An enormous floating aluminium parallelotope is an imposing object where he wanted to express an enormity, like a looming cloud in the distance that, undetected, creeps up on you. He has also modified architecture and created furniture. A creative that is able to comment on spatial themes in so many forms is quite amazing.