R-value (insulation) typical straw bale houses have very thick walls and thus are well insulated. Snow is roughly R-1 per inch. Brick has a very poor insulating ability at a mere R-0.2 per inch; however it does have a relatively good thermal mass. Note that the above examples all use the U.S. (non-SI) definition for R-value. When determining the overall thermal resistance of a building assembly such as a wall or roof, the insulating effect of the surface air film is added to the thermal resistance of the other materials. In practice the above surface values are used for floors, ceilings, and
R-value (insulation) it does not produce any quantitative data. This method can only be used to approximate the U-value or the inverse R-value. This approach is based on three or more temperature measurements inside and outside of a building element. By synchronizing these measurements and making some basic assumptions, it is possible to calculate the heat flux indirectly, and thus deriving the U-value of a building element. The following requirements have to be fulfilled for reliable results: The U-value can be calculated as well by using a heat flux sensor in combination with two temperature sensors. By measuring the heat that is