Anyone who lives here will tell you this place is special. Anyone who builds here KNOWS that it is. Chattanooga is a temperate rainforest. The average rainfall is 52 inches a year. Last year we got 67. In contrast, “rainy” Seattle gets a measly 35 inches a year. And the rain doesn’t fall in gentle showers either. It comes in a deluge, driving sideways so hard and so fast the atmosphere is more water than air. When it’s not raining, the humidity is usually above 90% both winter and summer. Temperatures range from lows of about 0 degrees Fahrenheit in winter to summer highs of around 95 degrees fahrenheit. The ground will freeze and thaw as many as a dozen times over the course of a single winter and the southern sun beats straight down in the summer.
All this is to say that our local climate is hell on buildings and has serious consequences for the way we design. Those lovely modern boxes with clean lines and clear finished vertical wood siding? Forget about it. Vertical siding if it’s not detailed carefully and kept away from the ground will soak up water and rot from the bottom up. And any siding is in for a hard life if it isn’t shielded from blowing rain and harsh summer sun.
I do use vertical siding sometimes, but I’m careful about it. I use metal if the project calls for it and if I use wood I try to keep it well away from the ground and protect the vulnerable end grain. I’m a huge fan of long roof overhangs, even on commercial buildings. I use them all the time. Roof overhangs get the water away from the building fast. They protect the vulnerable top of the wall from driving rain, and in summer, they shade the walls and windows.