Global energy efficiency can be obtained in two ordinary ways. One way is to improve the energy production and supply side, and the other way is, in general, to reduce the consumption of energy in society. This paper has focus on the latter and especially the consumption of energy for heating and cooling our houses. There is a huge energy-saving potential in this area for reducing both the global climate problems as well as economy challenges. Heating of buildings in Denmark accounts for approximately 40% of the entire national energy consumption. For this reason, a reduction of heat losses from building envelopes are of great importance in order to reach the Bologna CO2
emission reduction targets. Upgrading of the energy performance of buildings is a topic of huge global interest these years. Not only heating in the temperate and arctic regions are important, but also air conditioning and mechanical ventilation in the “warm countries” contribute to an enormous energy consumption and corresponding CO2
emission. In order to establish the best basis for upgrading the energy performance, it is important to make measurements of the heat losses at different places on a building facade, in order to optimize the energy performance. This paper presents a method for measuring the heat loss by utilizing a U-value meter. The U-value meter measures the heat transfer in the unit W/Km2
and has been used in several projects to upgrade the energy performance in temperate regions. The U-value meter was also utilized in an EUDP (Energy Technological Development and Demonstration Program) focusing on renovation of houses from the 1960s and 1970s.