materials and moisture

Lately, we've been having a bit of trouble with some of the wood siding on our home. It is getting wrapped in places, and it is also turning green near our back deck. This leads me to believe that it is getting moisture behind the it (warping) and that the paint isn't keeping the wood from staying too moist (green stuff). We had similar green growth on our deck, but managed to clean it off with a bleach solution from the hardware store. I'd do the same thing with my siding, but I'm concerned that the solution may bleach the house paint or even remove it. I have no idea how many layers of paint there are on the house, and the last thing I need is some glaring undercoat showing through. With our deck, it was no big deal since we were restaining it anyway.

This got me thinking about building materials and moisture. In areas that tend to be humid, why do they even try to build exterior walls with wood? Why not stick to more impervious materials like brick and stone? I guess they are too expensive, but so is replacing the exterior walls of your home. I know that there are certain types of wood (like cypress) that are supposed to be more moisture-proof but they are getting sparse. We could try residing the home in vinyl but I never really liked the way it looks. So I'm thinking that at some point we may have to add stone facade where the warped siding is now, along the lower half of the home. There are some decent priced fake stone options, some of which we may even be able to install ourselves.

One thing is for sure - if we ever decide to build our own home in this area, I'm going for the real thing, even if it costs me extra.