Plant grows out of building

I was on my way to the doctor when I came across this upstart plant. It had the nerve to grow out of the side of a building!

I thought perhaps it had grown from the ground up behind the metal panel between the two windows, emerging mid-building.
A closer look revealed that it hadn't come from the ground at all, but had taken root halfway up the building.
Whenever I find something like this, it reminds me how temporary our buildings are, without a human to maintain them. Plants, water, wind and weather are much stronger than concrete, given enough time.