Living in the Pacific Northwest, One sees moss and lichen growing in abundance. Occasionally on the sidewalk you can even see a line of it growing directly below the drip edge of a storefront canopy. I love it! Who doesn't love foliage on buildings. The Michigan Union - HELLO? One thing that I wish had been covered in order to be able to take this seriously, and it's something I've been curious about for a while:
The growth of Lichen is one of the first stages in erosion. It gets into the cracks of masonry and deteriorates. I know this is a very slow process but an important one at that. Nowadays stone and concrete cladding is just that - skin. It has no structural bearing. I'm thinking that for most buildings, panels could be replaced if they're ever in danger of crumbling, but I'd at least like to hear a little science on this. And in New York, where there are plenty of structural masonry buildings still (each potentially becoming heritage status), this could be an even bigger problem. Wow. I feel like a major buzzkill now.