The use of renewable energy sources towards autonomous buildings is promising, not only for electrical energy generation but also for heating purposes. However, it presents one fundamental issue: the shift between energy production and heating energy demand. This paper presents a solution to this problem in the form of an optimized, thermally controlled storage using phase change materials integrated to building walls. In contrast to the standard applications of phase change materials, which are currently used to solely improve the thermal inertia of buildings, this paper introduces an active management of heat storage. In particular, it allows the heat energy discharge through the activation of forced convection on demand. A test bench was designed and manufactured. Measurements performed showed excellent agreements with simulated results.