## 5 Conclusions  
The paper presents a methodology for the selection and evaluation of renovation alternatives with the nearly Zero Energy Building (NZEB) target. The outline of the method can serve as a flowchart that presents steps for data acquisition and handling in a structured manner, with the aim of simple, transparent, and justified decision making. The methodology is applied to a case study, where the performed analysis points to the following conclusions.  
The cost-effectiveness parameter (CEP) can be useful for estimating cost-benefits of various energy producing and saving actions. Although some discrepancies are noticed when comparing single action ranking based on the CEP and NPV, most actions retain their relative order.  
The CEP can be used for the sorting of renovation actions across different levels, depending on the focus of the project. As demonstrated, sorting across pre-selected building element types, or all elements, yields different contents for renovation packages. The results also showed that creating a package, solely based on the CEP, provides a package with the largest savings for the least cost increase. Although the results in this area are promising, further research including a higher number of packages is needed.  
Even though the selected case study buildings require an energy demand reduction of about 80%, applying the proposed method converged several solutions satisfying the NZEB target. This can partly contribute to the large amount of energy-saving measures applied in this study; however, in cases where the initially determined single actions are limited and none of their combinations satisfies the targets, the user can iterate back to creating one or more single actions or variants of the already determined actions.  
Analyses related to renewable energy production show that in nearly all cases, it is cheaper to implement a renewable energy system than do nothing. A considerable difference in both energy and cost is noted for the investigated main supply systems. Heat pumps prove to be most favorable when the target is NZEB. It was shown that the primary energy factor plays a big role in reaching a limit value for building energy class.  
Further studies should explore the robustness of the proposed method and the sensitivity of the different economic and energy parameters. Another viable topic could be to expand the current methodology with more evaluation parameters beyond economics and energy efficiency. Those could be related to a reduction of CO\({}_{2}\) emissions, greenhouse gases, or comfort indicators for the occupants.  
Conceptualization, all authors; methodology, Y.I.A.; validation, all authors; formal analysis, Y.I.A.; investigation, Y.I.A.; resources, P.K.H. and M.Z.P.; data curation, Y.I.A.; writing--original draft preparation, Y.I.A.; writing--review and editing, all authors; visualization, Y.I.A.; supervision, M.Z.P. and P.K.H.; project administration, M.Z.P. and P.K.H.; funding acquisition, P.K.H. All authors have read and agreed to the published version of the manuscript.  
This research was funded by European Union's Horizon 2020 Research and Innovation program, grant number 768576.  
The data presented in this study are openly available in Zenodo repository at [[https://doi.org/10.5281/zenodo.4452206](https://doi.org/10.5281/zenodo.4452206)]([https://doi.org/10.5281/zenodo.4452206](https://doi.org/10.5281/zenodo.4452206)).  
The authors declare no conflict of interest.