This standard describes a method for determination of the thermal resistance of building elements by simultaneous measurement of the heat flow rate and the temperature difference and by integrating the test results for a longer period of time.
With this method the thermal resistance can be measured on walls and roofs of buildings in use. The method is primarily applicable to building elements without local thermal bridges. When measuring on e.g. stud structures the method does not allow a correct weighting of insulated parts and studs. However, an estimation of the effects of the thermal bridges may be done with the help of thermography.
The method may be applied in order to obtain information about the thermal resistance of an old structure with unknown material contents e.g. when considering additional insulation. The method may also be applied when checking the performance of added insulation.
The determination of the thermal resistance of a building element in accordance with this standard must be related to the building under investigation and be carried out by persons having sufficient knowledge in the fields of building technology, building physics and measurement techniques.