This article is closely related to the oldest article titled Contribution to Active Thermal Protection Research—Part 1 Analysis of Energy Functions by Parametric Study. It is a continuation of research that focuses on verifying the energy potential and functions of so-called active thermal protection (ATP). As mentioned in the first part, the amount of thermal energy consumed for heating buildings is one of the main parameters that determine their future design, especially the technical equipment. The issue of reducing the consumption of this energy is implemented in various ways, such as passive thermal protection, i.e., by increasing the thermal insulation parameters of the individual materials of the building envelope or by optimizing the operation of the technical equipment of the buildings. On the other hand, there are also methods of active thermal protection that aim to reduce heat leakage through nontransparent parts of the building envelope. This methodology is based on the validation of the results of a parametric study of the dynamic thermal resistance (DTR) and the heat fluxes to the interior and exterior from the ATP for the investigated envelope of the experimental house EB2020 made of aerated concrete blocks, presented in the article “Contribution to the research on active thermal protection—Part 1, Analysis of energy functions by the parametric study”, by long-term experimental measurements. The novelty of the research lies in the involvement of variant-peak heat/cooling sources in combination with RES and in creating a new, original way of operating energy systems with the possibility of changing and combining the operating modes of the ATP. We have verified the operation of the experimental house in the energy functions of thermal barrier, heating/cooling with RES, and without RES and ATP. The energy saving when using RES and ATP is approximately 37%. Based on the synthesis and induction of analogous forms of the results of previous research into recommendations for the development of building envelopes with energy-active elements, we present further possible outcomes in the field of ATP, as well as already realized and upcoming prototypes of thermal insulation panels.