Most of the glass we see in contemporary cities isn't transparent in the sense that Gothic stained glass or a shop window once was: it's reflective. Low-E coatings and solar-control glass, applied to reduce a building's thermal load, have the side effect of turning the facade into a large mirror that reflects the sky, the clouds, the building across the street — showing everything except what's actually happening inside. It's in this context that the work of the Japanese studio SANAA, founded in 1995 by Kazuyo Sejima and Ryue Nishizawa, takes on an almost polemical meaning: an entire career built on the premise that glass should be looked through, not looked at.
The 21st Century Museum of Contemporary Art, Kanazawa
Kanazawa's 21st Century Museum of Contemporary Art (2004) is perhaps the clearest statement of this principle. The building is a perfectly circular disc, with an entirely glazed perimeter and no recognisable main facade: from wherever on the circle you approach, you see straight through the building to the park on the other side, and the entrance can be, literally, at any point on the circumference. Sejima theorised this approach as "diagram architecture": a building that rejects the traditional hierarchy between front and back, between main entrance and secondary facades, precisely because the transparency of the perimeter glass makes every point on the circle equivalent to every other. A visitor walking around the building always sees, through the glass, the exhibition rooms and the people inside them — not a reflection of themselves or the sky.
The Glass Pavilion at the Toledo Museum of Art
At the Toledo Museum of Art in Ohio, SANAA completes the Glass Pavilion in 2006: a series of rooms with curved walls, made from float glass bent while hot — not flat panels joined at an angle, but continuous, curving surfaces — with a supporting structure reduced to the bare minimum, almost invisible. The building itself houses the museum's glass-working studios: the choice to clad in glass a building dedicated precisely to glassworking is no accident, it's a deliberate short-circuit between content and container. The curved walls, with no sharp corners and no visible mullions, create a sequence of spaces glimpsed one inside the other through multiple layers of glass — an effect of depth and overlap that the flat transparency of an ordinary glazed wall couldn't produce.
Transparency versus reflection: why the difference matters
The difference between a building that uses glass to reflect and one that uses it to be seen through isn't just aesthetic: it's a choice about the relationship between the building and the city. The mirrored skyscraper, however elegant, communicates a message of self-sufficiency and distance — it reflects the outside world instead of letting it in, and hides the building's inner life behind a veil that's opaque to sight despite technically being "glass." SANAA's buildings, by contrast, treat transparency as a civic value: they make an institution's inner life visible from outside — whether it's a museum, a university library, a civic centre — turning the facade into a threshold permeable to the gaze rather than a reflective barrier. This requires precise technical choices: extra-low-iron glass to minimise the greenish tint that would compromise the colour neutrality of the view through multiple layers, and solar control achieved not through reflective coatings but through shading, curtains, or simply the building's orientation and geometry — accepting a more demanding energy trade-off rather than sacrifice true transparency.