## 4 Conclusions  
Based on the theoretical analysis in the field of energy solar roofs (ESR), ground heat storages (GHS), and active thermal protection (ATP), as well as the research carried out on the IDA I prototype prefabricated house and the experimental family house EB2020, the following statements can be made:  
* The application of an energy (solar) roof (ESR) requires lower investment costs than conventional solar collectors, but experimental measurements have shown that the energy gain and the achieved outlet temperatures of the working fluid are significantly lower. To increase the ESR efficiency, applying a dark-colored roof covering is important and installing more circuits with a suitable distribution according to cardinal directions is important. * The use of ESR for low-temperature heating or supply of active thermal protection can only be implemented with a suitable heat storage solution. For hot water production, the ESR can only be used for preheating. The ESR could also be used as a collector for a heat pump, which would serve for heating, domestic hot water preparation, and cooling. * Heat accumulation in a conventional house slab foundation as a ground heat storage (GHS) is limited only to the application of active thermal protection in a thermal barrier (TB) function. It is insufficient for heating and domestic hot water. Heat accumulation from ESR and peak heat sources is recommended in large-capacity water storage tanks or in storage tanks with the change of state. * The use of ATP in wall heating and cooling is of practical significance only in building constructions with a high accumulation capacity on the inside in front of the ATP tubes, i.e., high bulk density, thermal conductivity, and thermal capacity, e.g., reinforced concrete. * Building structures that have a high thermal resistance in front of the ATP pipes are only suitable for the thermal barrier function. Parametric studies predict such structures to achieve high equivalent thermal resistance at relatively low mean temperatures of the heat transfer medium. For example, +10 to +15 \({}^{\circ}\)C represents a design with thermal insulation of 300 to 800 mm, see Table 1 in Section 3.1.1. * Based on the analysis of the parametric study results of the energy potential of individual technical solutions of reinforced concrete envelope panels with integrated energy active elements in Section 3.2., it can be concluded that the increase in heat loss due to the location of the tubes in the structure closer to the exterior is negligible for VARIANT II, semi-accumulation heating (TABS system), and VARIANT III, accumulation heating, compared to VARIANT I, direct heating, below 1% of the total delivered heat flux, Figure 30. The direct heat flux to the heated room is 89.17% for direct heating, VARIANT I, 73.36% for semi-accumulation heating (TABS system), VARIANT II and 58.46% for accumulation heating, VARIANT III of the total delivered heat flux, Figure 30. For simplicity, VARIANT I does not consider heat accumulation for the panel. For the panel design (TABS system), VARIANT II represents 14.84% and VARIANT III up to 29.86% heat accumulation of the total delivered heat flux, Figure 30. Variants II and III appear promising in heat/cool accumulation with an assumption of lower energy demand (at least 10%) than for low inertia walls. Variants in how energy systems operate represent energy-safe and environmentally friendly technical solutions that need to be adapted and optimized case-by-case based on all input requirements. Based on the design, project, and implementation of the prototype of the prefabricated house IDA I and the experimental house EB2020, we have created variants of functional measurement and control schemes for the interconnection of all energy systems, which, in synergy with the building control system optimize the mode of operation in buildings using combined building-energy systems. We have also defined operational strategies for the individual energy systems, Section 3.1.