For heating, energy sources based on fossil fuels use are prevalent. Not only brings this negative influence on the environment, but also represents high economical costs. In my thesis, I summarise four experimental studies in which authors are discussing the benefits of using phase change materials in floor heating systems. All the studies show that phase change materials lowers the energy needs for achieving comfortable living conditions and allows economical savings by shifting the energy consumption to off-peak periods. Results of the studies shows great benefits in using phase change materials in construction. Their use is not limited to achieving comfort living conditions in aspect of heating but also applies to cooling.