Guardrails are important architectural elements with competing design priorities. For example, they must be low enough to permit a seated view. They need to have intermediates spaced to keep children safe, must prevent climbing and, of course, must be strong enough to lean against without toppling over. Throw transparency on top of these priorities and you can see how complicated things can get. My listing at 3027 NW Rio Vista Terrace is an example of the impact a transparent guardrail can have, because it allows the panoramic city, mountain and river view to be almost uninterrupted from the decks.