Woods and walls

One of the interesting aspects of the human mind is how it can draw parallels between seemingly unrelated subjects. It happened to me this morning while reading a blog post about biomass and its place in our energy future.
A concern raised by one poster, and a concern I share, is the potential over harvesting of our wood resources by companies more concerned about supplying their boilers than sustaining the resource. 
My short take on this is that the answer is to apply strict management to the resource or leave it alone.The leave it alone approach, no harvesting at all, is unrealistic. Wood is too useful a resource to suddenly decide that we can forgo its use altogether. If we are going to harvest wood we need to apply resource management techniques that maximize yield while preserving the forest and all the environmental benefits it supplies.
A little management, maximizing yield only, leaves us with the situation with large clear cuts and the associated problems of air, soil and water quality problems. Strong management using sustainable harvesting techniques and using plans that address the specific site can result in a forest that can sustain wildlife, soil, water and air. So if we are going to take and use the resource we need to invest our time and energy to gt the details right.
I can apply that same management logic to the exterior walls in a building. For years we got away with minimal management of air and water movement in our outside walls. All we had to do was keep most of the water out and the uninsulated un-air-sealed walls survived just fine. The water that got in, and it did, dried quickly enough because there was enough energy flowing through the walls to evaporate and disperse the water.
Then we started asking these walls to do more. To hide the wires and pipes our increasingly technology based lives demanded. And we added insulation to keep us warmer and we asked for fewer drafts so we could wear light clothing in the winter. But we didn't do much to improve our management of the water. It still got into the walls, but now the energy flows available were greatly reduced so it stayed there longer.
Water is the great giver of life. All life forms that we know about need it. Unfortunately the life forms that tend to grow in warm dark damp places like the inside of walls are know by names like mold and rot.
A quick aside if I may, there is no such thing as dry rot. You just didn't see it when it was wet.
Back to topic: If we are going to continue to extract all these services from our walls we need to more vigorously manage the water. Exterior drainage planes and properly installed windows and doors on the outside are a good start. Exterior insulation to control condensation on the inside of the wall is a great idea too.
Inside the walls we need to use materials that reduce air movement and are moisture tolerant. We need to make sure our interior wall surfaces minimize air movement yet still allow for drying (If we are going with the drainage plane/exterior insulation). Pay attention to ventilation to control humidity and be vigilant about controlling bulk water. If we do these things we can have walls that provide the services we want and that will last a long time.
So whether it's forests or walls, if we want them to serve us we need to be willing to devote the effort to manage and maintain them. It's only fair.