 Be aware of this issue of moisture in-house, needs to go out, wants to go out, you're not. Okay, so one of the main things a building has to do is to balance moisture. So we create moisture inside by cooking, by sweating, by washing, showering, and the moisture in a house must go out. Of course we can open windows, but we won't open windows 24 hours, so we do have moisture inside the house that's different from outside. If outside temperature is 20 degrees, no problem, but in climates with either winter or with tropical temperatures with high moisture, this becomes a real issue. And so if you have a wall, and this is the inside, so people would live here, and there is moisture here in the air. And now the wall, there is minus 10 degrees outside, for example. So here the wall will be getting very cold, even inside into the construction material. And then the moisture would evaporate into the wall. And then we have something that is crucial for all types of buildings, especially for ecological building. That's the condensation point. In German it's taupunkt. And this will be somewhere here where there is zero degrees. And what happens when water vapor is getting colder? Condensation. And if we have condensation inside the wall, this can actually create mold to grow, so the construction material can deteriorate. And for preventing this, there are normally liners, plastic material in there. And in houses that have this plastic material, the climate in the house is disrupted. So for ecological housing, we don't want that. We want to have walls where the water vapor can move through. And at the same time, we need to avoid the problem with having water condensating in the wall that creates problems. And this is a bit tricky, but to cut that short, if that material where the water is condensating is resistant to water, like mineral materials or also very dry wood that can absorb a lot of water, this will not harm the building. But if it's a material that is in risk of getting moist, like a lot of insulation materials, when they get moist, they don't do insulation anymore. They start rotting. And this is something that we have to look out for. And that's why I love so much loam bricks. For insulation, they will be often mixed with straw. And this should be straw of plants that create very strong straw, like hemp or linseed. And these are very, very strong little stems that make good insulation. So it's mixed into the loam when we make the bricks. And then the insulation capacity is very good. Water vapor will go through. And for wood, the situation is also pretty good because massive wood evaporates water. And if it's condensating at some point, it doesn't harm the wood. So massive wood can be built without a liner making a very nice climate. And my personal preference for building echo houses is to have massive wood for outside walls and air dried loam bricks for inside walls to have some mass for passive solar. And there are some nice methods of building in that way.