Round 1

Reviewer 1 Report

1. The study takes 2008 and 2009 as the benchmark (M01) for energy-saving improvements (lines 282 to 283); 2019 (M02) is the energy-saving outcome of the improved plan (line 284), and then takes M02 as the benchmark by re-drawing up the third plan for improvement (lines 285 to 286). Please illustrate the reason that the design of the improved plan in 2019(M02) is unable to complete, whereas it needs another improved plan in the latter days.

2. The study uses the same parameters to perform the three modes of energy consumption simulation, such as the use of COP 4.02 heat pumps (lines 443 to 444) and the same lamps and electrical equipment (Table 1). The energy efficiency of the equipment in 2019 must be higher than the energy efficiency of the equipment at that time in 2009. Therefore, if the heat pumps, lamps and electrical equipment’s efficiency in 2009 (M01) are different to the spring of 2019 (M02), it should be reexamined the situation of energy consumption after the improvement. After all, equipment energy saving is also part of building energy saving.

3. This study simulates the use of energy efficiency in the three modes at the monastery restaurant. The simulation of EnergyPlus energy software shows that M02 and M03 have better energy-saving outcomes than M01 (line 465, Table 2). However, the restaurant in actual operation and usage condition is different from the simulation of dynamic energy software within a perfect condition setting. It has been a year since the improvement in the spring of 2019. Please provide the additional information on the actual electricity consumption of the restaurant after the improvement of the housing insulation (M02) but also before the improvement (M01).

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The paper deals with the restoration and improvement of energy efficiency and comfort conditions of historic buildings, maintaining the authentic visual appearance of the facility and its materialization. This issue is interesting. Here are some comments that could help to improve the paper: The title is confuse, there is no renewable and sustainable energy research in the manuscript. It is suggested better to focus on energy efficiency and/or energy saving

Introduction. The background is poor. The literature review related to energy efficiency, comfort of historic buildings should be extended. It would allow to better understand the problems of these buildings and to expose different improvement proposal solutions. E.g. these issues and papers may be considered in the literature review:

-       Energy retrofits in historic buildings methods: https://doi.org/10.1016/j.rser.2017.01.145

-       Energy efficiency guidelines on historic buildings: European Committee for standardization (CEN). Conservation of cultural heritage. Guidelines for improving the energy performance of historic buildings, EN 16883:2017 2017.

-       Preservation of works art and thermal comfort: doi: 10.3390/su10113838

-       The discrepancy between actual performance and simulations: https://doi.org/10.1016/j.rser.2019.109509

The aim/goal of the paper appears several times in the manuscript (lines 43-45, 50-60, 132-134, 160-167) and not always in the same way. It is suggested to indicate it at the end of the introduction.  

Methodology. The word 'Methodology' should be 'Methods'; methodology is the study or analysis of methods. The authors propose “a methodology for the restoration of historic buildings and their reuse and sustainable renovation in terms of energy efficiency”. The novelty method of the work should be clearly defined in this section. After developing the method, the case study is applied.Some important issues should be explain: Is there no in situ measurements data? What criteria are used to determine concrete improvement energy solutions? Has some kind of optimization process been applied? Why is there no cooling analysis?

Energy efficient restoration sub-section, much of all this part should be in methods section.

The recommendations and conclusions should not be generic and they must be based on research develop in the manuscript. E.g. Where is the optimal thermal insulation of building envelope (line 565)? 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

It is a very interesting work that will probably haves a positives outcome, at various levels, for the Monastery of Žiča and for the user’s satisfaction of this rich architectural heritage.

However, in terms of the results of the impact on the sustainability of the building, it is not very clear to readers what the real benefits are since the research and the article are based on various restoration models and not in their practical application. Thus, the title should refer to this reality.

In terms of article construction, I would have liked to have seen a strong review of the literature, as a substantial conceptual definition and a properly construction of the conceptual scheme.

There is also no comparative study of the methodologies used in relation to other historic buildings with identical characteristics.

Although the implementation of the concept of reversibility has taken into account in the introduction and the objectives of the project, the actual reversibility of the materials, introduced in the improvement and efficiency of the energy sustainability of the building, is never addressed or explained during the construction of the article, so it should be improved.

The conclusion should be clarified according to the objectives of the research outlined and initially pointed out.

English needs some improvements.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I appreciate the effort of the authors to improve the paper. Nearly all my comments have been addressed. In my opinion, the quality of the manuscript is sufficiently increased to be accepted for publication in this Journal.