The R-value of a layer can be estimated by multiplying its thickness in inches by the R-value per inch. The R-value of a structure made of layers of different materials can be estimated by adding the R-values of the layers. In the German standard DIN 4701, this quantity is called “K”. ISO-DP10292 draft standard and CEN-ISO 9050. To convert a European U-value to an American R-value, multiply by 0.176, then divide 1 by the result.ġ. This is not the reciprocal of the American R-value (kelvin instead of degrees Fahrenheit, meters instead of feet, etc.) To convert an American R-value into a European U-value, divide 1 by the R-value, then multiply the result by 5.682. There, U-values are defined¹ by the equation: In Europe it is customary to use U-values instead of R-values. The higher the U-value, the better the conduction of heat. The reciprocal of R-value (1/R) is known as the U-value. If you know the R-value of a partition, you can use this formula to find the heat loss. Most of the time these materials will require some additional facing to protect them from the elements though, so plan ahead for this.Where the temperature difference is in degrees Fahrenheit between the two sides of the insulation, the area is in square feet, the time in hours, and the heat loss in Btus. The primary advantage in using these types of materials is that there is no need for separate insulation to be installed, which saves you the cost and hassle of doing this.Īnother key advantage is that these materials don’t require a standard housing frame, eliminating any possibility of thermal bridging and making them very effective and uncomplicated in practical terms. These include structural insulation panels (SIPs), straw bales and autoclaved aerated concrete (AAC) blocks. Some building materials are specially chosen for the fact that they already incorporate insulation into their design. Structural materials with insulation properties Your structural and cladding materials, along with your insulation, will contribute to the overall R values of these parts of your home.

There are minimum R-value requirements for these parts of your home specified under the Building Code of Australia (BCA) - and dictated to by the state and climate zone in which you live.

Thermal mass properties, the thickness of the material and the method of construction will change the R-values of your walls and roof. Advertisement Overall R values for different parts of your homeĬhoosing what sorts of materials you will use to build your house will make all the difference when it comes to insulating your home.

R value of 12 cmu block