To me, sustainability means creating a design with the minimal amount of energy possible and materials that are locally sourced, high quality, and created using the minimal amount of energy and/or with a minimal negative impact on the planet. I think LEED certifications are a good guideline for sustainability, so I’ve linked the checklist below.
A sustainable building is one that will stand the test of time, use as little energy as possible, is considerate of the local community, and hopefully, creates something that benefits that community (in this case, it could be a public park or outdoor area, or maybe the exhibition space is free to locals)
I think it could also be cool to add some new technologies that have come out recently like windows that are photovoltaic, but you can see out of them. I’ve also heard about windows that will automatically adjust the blinds to minimize excess heat.