Energy Efficiency versus Heritage—Proposal for a Replicable Prototype to Maintain the Architectural Values of Buildings in Energy Improvement Interventions on Facades: The Case of the Expansion of San Sebastián

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors provide a proposal for a replicable prototype to regulate energy improvement interventions on facades. However, there is no any quantitative analysis in the manuscript. It looks more like an investigation report. In addition, I think the manuscript is not in the scope of Coatings. Other comments are as followings.

1. The description of "Fig 1" in line 72 and "Figure 1" in line 76 is inconsistent.

2. 248 Line sentences are not aligned at both sides.

3. The title of the picture in the text is centered but the picture is not.

4. 422 Line sentences without punctuation at the end.

5. There is no header between lines 480 and 482, but one line is left blank.

6. Figure 3 shows the adjusted research method, which is then detailed in 3 steps and 3 stages, but the difference between the above 3 steps and 3 stages and the difference between the two contents cannot be seen from Figure 3.

Author Response

We thank the reviewer for the comments made on the submitted article as they will allow us to improve its comprehension. In response to the comments made, the reviewer indicates that there is no quantitative analysis in the article regarding the application of the proposed prototype for regulating energy improvement interventions in facades. The presented article does not intend to quantitatively assess the improvement in energy efficiency resulting from the application of the investigated replicable prototype. The research is based on establishing a formal and constructive limitation on energy rehabilitation interventions applied to unprotected buildings in consolidated urban areas through the development and design of a quantitatively replicable prototype, which objectively defines the degree of vulnerability of these unprotected heritage buildings. This ultimately allows defining and granting criteria and modes of intervention in their energy rehabilitation, integrating it into the nearby urban environment without implying a loss of unprotected architectural heritage. 

However, the authors consider that precisely this is the most significant innovation that the research brings. With the aim of defining intervention criteria as objectively as possible, a prototype has been designed to measure building vulnerability quantitatively. 

Furthermore, to clarify this aspect, a new figure has been included in the article illustrating the quantification ranges that define the flexibility that a facade intervention can have in each building. 

Additionally, the formal issues indicated by the reviewer have been corrected. 

Finally, the article has been restructured, and a new paragraph has been included, clarifying the methodology developed in three phases and three stages, describing the steps taken in each. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper illustrates the implementation of energy efficiency improvements in façades and highlights the consequent widespread modification of these structures. 

The text is well argued, the structure is good and the references appropriate. 

Some suggestions: 

- improve the clarity of terms. The text introduces terms such as 'ventilated façades, EIFS systems, new cladding materials and, finally, TBI' without providing clear definitions or explanations for readers who may not be familiar with these terms.

- Although the text outlines the steps of DSRM, it lacks specificity in describing how each step is carried out or how the methodology is applied to the research project.

- The text mentions that the methodology was adapted to the specific characteristics of the research project, but does not elaborate on how or why these adjustments were made.

- Although the text mentions the use of a focus group to gather feedback on the research methodology, it lacks specific details on how the focus group was conducted, such as the number of participants, the criteria for selecting experts, the structure of the session and how the feedback was analysed and incorporated into the methodology.

- The text uses terms such as 'V0 prototype', 'V1' and 'V2' to describe the different versions of the methodology, but does not clearly explain what each version entails or how they differ from one another. Please, clarify.

- The authors could better explain how this method differs from others and what innovative contributions it brings to the state of the art. It could be useful to cite other studies on the analysis of historical facades, such as: P. Cucco, Heritage impact assessment in UNESCO WHS. An approach for evaluating human-induced alterations in traditional building’s facades, Proceedings Colloqui.AT.e 2023 “In Transition: challenges and opportunities for the build heritage”, Edison Edizioni, Milano, 2023, pp. 177-192; Bersch J D, Verdum G., et al. Diagnosis of Pathological Manifestations and Characterization of the Mortar Coating from the Facades of Historical Buildings in Porto Alegre — Brazil: A Case Study of Château and Observatório Astronômico. International Journal of Architectural Heritage, 15: 1145-1169, 2020; Munari Probst, M.C., Roecker, C., (Eds.). Solar energy systems in architecture - integra- tion criteria and guidelines. Deliverable T.41.A.2 of IEA SHC 41 Solar energy and Architecture, September 2012; Polo Lòpez C. S. et alii, 2012, Optimization of Energy Interventions in Building of hi- storical-Architectonical value (ENBAU), Lugano-Canobbio: Scuola Universitaria Professionale della Svizzera Italiana; F Ribera, P Cucco, IJG Crespo, Energy efficiency features in italian and spanish traditional dwellings, SUSTAINABLE MEDITERRANEAN CONSTRUCTION 12/2020, 178-183.

Author Response

We appreciate the reviewer for the comments made on the submitted article as they will help improve its comprehension. 

The suggestions made by the reviewer have been taken into account. Each of the acronyms introduced in the text has been detailed. Additionally, a new paragraph has been added to the text, explaining in detail each step taken in the different phases of the DSRM methodology. Furthermore, the tasks carried out by the focus group have been specified to endorse and validate the final prototype. Clearer descriptions have also been provided regarding the differences between the various versions of the prototype. Finally, the suggestions regarding the references have been considered, and some of them have been included. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The title must be revised. I suggest the following title"Balancing Energy Efficiency and Heritage: A Prototype Proposal for Regulating Facade Improvements - A Case Study of San Sebastian Expansion".

The abstract should clearly address the main objective and the quantitative aspects of this study.

Start the introduction by the following paragraph "The homogenization brought about by globalization emphasizes the pressing need to revitalize cultural distinctions, particularly in urban planning and design. Preserving the unique cultural heritage of each locality is paramount to safeguarding its identity amidst rapid urbanization. Effective conservation measures entail regular maintenance and occasional adjustments to accommodate evolving needs. Without proper documentation and protection, heritage sites are vulnerable to distortion or loss. Therefore, urban planners and designers must prioritize the development of tools and strategies to ensure the sustainable preservation of cultural heritage in urban environments (Marghany 2014 and Elmahdy et al., 2016 )".

Marghany, M. (2014, June). Fuzzy B-spline optimization for urban slum three-dimensional reconstruction using ENVISAT satellite data. In IOP conference series: earth and environmental science (Vol. 20, No. 1, p. 012036). IOP Publishing.

The authors are urged to provide a more focused and in-depth exploration of the challenges related to urban design and building preservation, offering specific examples to illustrate their points. Additionally, the objective of the study lacks novelty and may not captivate readers' interest. Therefore, the authors are encouraged to revise the objective and introduce a unique perspective or innovative approach to enhance the appeal of their research.

Incorporate Figure 2 into the study area section, enhancing it by including geographical locations, scale bars, and a legend for the names of places. Additionally, consider including a larger map to provide context for the country.

The data analysis section requires significant improvement. It is crucial to include modeling, measurements for buildings, 3D analysis, and possibly statistical models to assess the accuracy of the study. At this stage, I cannot recommend this paper for publication, but with major revisions, it has the potential for publication in the future.

 

 

 

Comments on the Quality of English Language

Need to be polished.

Author Response

We thank the reviewer for the comments made on the submitted article as they will help improve its comprehension. Following the reviewer's suggestions, the main objective and quantitative aspects of the study have been incorporated into the abstract. 

The reviewer suggests taking a different approach focused on the challenges with urban design and building preservation. However, the issue in this environment is different. The city is already saturated, and there are areas where protected buildings coexist, where intervening in the envelope from the exterior is prohibited, with other unprotected buildings, where any intervention can be carried out, generating significant distortions in the urban landscape. The underlying concern is the gradual metamorphosis of the urban landscape, which, despite the existing legal framework for the preservation of protected buildings, is unable to maintain a clearly defined identity. It is clear that what determines the character of the city far exceeds the legally established protections, so the groundwork must be laid to limit interventions in all built heritage. This is the aspect addressed in the article. 

Following the reviewer's suggestions, several figures have been incorporated into the article that were developed during the research, generating three-dimensional models to test the intervention criteria allowed by the proposed prototype. 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript aims to determine a methodology to establish and limit criteria for façade interventions in historic centers. 

The manuscript is not structured well. The introduction describes the working area and the problems associated with renovation works in this area but not a literature review, giving examples of similar problems. The methodology section is repeated in the results section. The results of the study are not presented. An annex is given but in Spanish. There is no conclusions section. 

The work done is huge but not presented well. Furthermore, my opinion is the manuscript does not fit with the scope of the Special Issue. 

 

Comments on the Quality of English Language

Many Spanish words and figure titles exist.  Some grammatical errors are identified.

Author Response

We appreciate the reviewer for the comments made on the submitted article, as they will enhance its understanding. Following the reviewer's suggestions, an analysis of the state of the art has been conducted, and a paragraph has been added at the beginning of the introduction section to explain the existence of other similar research. However, the proposed article represents an advancement in research on the topic, as it presents a methodology that generates a prototype of objective, quantitative, and replicable analysis, endorsed by a panel of experts. 

  

The submitted article does not aim to quantitatively assess the improvement in energy efficiency resulting from the application of the investigated replicable prototype. The research is based on establishing a formal and constructive limitation of energy rehabilitation interventions applied to those unprotected buildings in consolidated urban areas through the development and design of a replicable prototype in a quantitative manner, which objectively defines the degree of vulnerability of these unprotected heritage buildings. This ultimately allows defining and granting criteria and modes of intervention in their energy rehabilitation, integrating it into the surrounding urban environment without resulting in a loss of unprotected architectural heritage. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

All the comments have been addressed.

Author Response

Thank you for your suggestions. They have helped us to improve the article

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have  done good revision. 

Comments on the Quality of English Language

The authors have done good revision. 

Author Response

Thank you for your suggestions. They have helped us to improve the article

Reviewer 4 Report

Comments and Suggestions for Authors

The authors revised the manuscript based on the comments. But, it became more complicated with more wording. I recommend simplifying the methodology with flow diagrams. The case study section includes more methodology. As I mentioned before, there is a vast work which makes the presentation of the manuscript quite complex. Instead of giving results of many building scenarios and sub-scenarios, it could be given only the results of one building as an example. 

Briefly, the study defines the character of the facades and the degree of vulnerability, and then recommendations are given for facade interventions. It is not possible to correlate the study with energy efficiency. Since it is concentrated on protecting the historic value of the building facades, the reason for the intervention could be other than the energy efficiency. No measure is included on energy efficiency. 

The conclusions section is missing. 

The manuscript still lacks novelty and is unsuitable for publication in the Special Issue. 

 

Comments on the Quality of English Language

A minor language check is required.

Author Response

Author's response to the review report (reviewer 4) 

 

We would like to thank the reviewer for his comments on the revised article, which will improve the understanding of the article.  Sub-sections have been made clarifying the methodology applied in the case study, a subject suggested by other reviewers (from whom we have already received their approval) and, which has already received their approval. Following the reviewer's recommendations, a simplified flow diagram has been incorporated into the article followed by the adapted flow for better understanding.   

The reviewer indicates that instead of giving the results of many scenarios and sub-scenarios of buildings, only the results of one building could be given as an example.  However, it is essential to apply the methodology to all the buildings in the scenario in order to contrast and guarantee that it meets the established objectives, and that it can be replicated in another area of the city or even in other cities. Furthermore, the article has already been approved by three reviewers, so it does not seem appropriate to make a change of this magnitude. 

The reviewer estimates that the study defines the character of the facades and the degree of vulnerability, and recommendations for intervention on the facades are presented below. It is not possible to relate the study to energy efficiency. Indeed, this article does not really intend to measure the energy efficiency of the improvement interventions in the façade envelope, but it does want to warn (and act) of the existence of the problem that is generated with this type of interventions, since we do not have (without take into account the distortion that is being generated in our cities, and especially in historic centers). In addition, lines of action are proposed so that possible interventions are as respectful as possible with the identity given by the built heritage. Improving the energy efficiency of buildings involves studying technical, urban and architectural parameters. However, the acceleration of the rehabilitation process, due to the existence of aid, has caused the normalization of the use of the SATE or ventilated façade, almost automatically, without a general study of the conditions of the building and its surroundings. The use of fire in unprotected buildings in historic centers is generating a distortion of the architectural heritage, especially from the 20th century, and a general loss of the urban image and identity of the cities. This is where this project is included, which serves as a tool for urban planners and public administrations, as a preliminary step to the study of systems to improve energy efficiency, to establish guidelines for the protection of architectural and urban heritage in exterior interventions. of the facades. 

The reviewer says that the article focuses on the protection of the historical value of building facades. Indeed, this research does not provide energy efficiency measurements, because it does not study the energy efficiency of buildings. It is about how to prevent non-protected buildings, but in heritage-sensitive urban centers, from undergoing façade modifications in ways that distort the urban and architectural identity of these unique spaces. The aim is to prevent the loss of architectural heritage. The energy efficiency of buildings can be achieved in many ways that do not involve the installation of an EIFS or ventilated façade. Therefore, the measurement of the energy improvement achieved is not relevant in this study. These buildings can be insulated on the inside, improve the boiler characteristics, improve the window characteristics, etc. In other words, the fact of regulating the installation of these external insulation systems has no influence whatsoever on the possibility of insulating these buildings correctly. The problems described here derive from the lack of a good urban/architectural/heritage study of the buildings before acting on them. A study of the improvement of the energy efficiency of a building cannot be complete without taking into account the urbanistic, architectural and heritage characteristics of the buildings. It is this prior research that we have carried out, because it is now absolutely necessary if we want to preserve space. In fact, this research does not include energy efficiency measurements, because it does not study the energy efficiency of buildings. We are looking at how to prevent buildings that are not protected, but in heritage-sensitive urban centres, from undergoing façade modifications in ways that distort the urban and architectural identity of these unique spaces. The aim is to prevent the loss of architectural heritage. The energy efficiency of buildings can be achieved in many ways that do not involve the installation of an EIFS or ventilated façade. Therefore, the measurement of the energy improvement achieved is not relevant in this study. These buildings can be insulated on the inside, improve the boiler characteristics, improve the window characteristics, etc. In other words, the fact of regulating the installation of these external insulation systems has no influence whatsoever on the possibility of insulating these buildings correctly. The problems described here derive from the lack of a good urban/architectural/heritage study of the buildings before acting on them. A study of the improvement of the energy efficiency of a building cannot be complete without taking into account the urbanistic, architectural and heritage characteristics of the buildings.. It is this prior research that we have carried out, because at this point in time it is absolutely necessary if we want to preserve urban spaces with heritage value. This is why we do not provide measurements of the interventions of energy efficiency improvements, as this is not the aim of the article or even of the proposed topics covered in the special issue.   

 

The reviewer warns that there are no conclusions. On reviewing the article, we have come to the conclusion that the case study is actually a description of the research findings and the findings are the conclusions of the research. The names of the last two subscripts have been changed to fix this error. 

Improving the energy efficiency of buildings involves the study of technical, urban planning and architectural parameters. However, the acceleration of the refurbishment process, due to the existence of subsidies, has led to the standardisation of the use of SATE or ventilated façade, almost automatically, without a general study of the conditions of the building and its surroundings. Its use in non-protected buildings in historic centres is leading to a distortion of the architectural heritage, especially from the 20th century, and a general loss of the urban image and identity of the cities. This is where this project comes in, which serves as a tool for designers and public administrations, as a preliminary step to the study of systems for improving energy efficiency, by establishing guidelines for the protection of architectural heritage in interventions on the exterior of façades.  

  

It is for this reason that an objective and quantifiable methodology is proposed, endorsed by a panel of experts from various disciplines, to limit or regulate how to intervene in each case. The results obtained have been compiled in a series of sheets (Figure 11). The application of the tested and replicable methodology demonstrates that the quantitative assessment of the degree of vulnerability of each building allows a level of flexibility in the interventions on the façade envelope. In the case of a building with a very high vulnerability, it may be impossible to act from the outside with an ETICS system or a ventilated façade. On the other hand, a very low vulnerability allows for flexibility in such interventions.  

  

In the case study, Table 4 shows the degrees of vulnerability of the architectural typologies studied, concluding that, except in the case of the sub-scenario of neoclassical buildings, the rest present a vulnerability of 100%, making it advisable to prohibit intervention from the outside, with the usual standardised solutions of ETICS and ventilated façade. This does not imply that the building cannot have an energy improvement with other strategies such as the placement of thermal insulation on the inside of the envelope and other solutions. 

Although the systematisation of the generation of regulations for the safeguarding of architectural heritage seems unfeasible, the implementation of the prototype in the case study has made it possible to verify its suitability as a better and more effective way of creating regulations. An objective and quantifiable methodology, endorsed by a panel of experts from various disciplines, has been designed to regulate how to intervene in each case.  In this way, the legislator has at his disposal a tool with which to systematically analyse and define a regulation for each type of building. The tool accelerates, systematises and facilitates the process.   

  

The conclusions obtained have proven to be a tool not only for the protection of heritage in the face of the rise of exterior building cladding, but also for any type of intervention on the exterior of the façade, understanding façade intervention as a fact that influences the identity of the built heritage independently of its individual heritage value.   

 

The conclusions of the case study have been presented to the corresponding administrations and they have requested the application of the prototype in a new area, through a contract. Therefore, it can be concluded that the work has been a great success due to the innovation provided and the methodology can be applied and improved in a new case study, in an area with somewhat different characteristics to the one studied, with a greater number of buildings and a variety of architectural styles.   

 

 The reviewer states that the manuscript still lacks novelty. Both the methodology used, and the prototype generated already represent a novelty since other references already incorporated in the article have been identified, which speak of the vulnerability of buildings to other types of risks, as reflected in the following text: 

 

As explained in the introduction, there are many studies on the vulnerability analysis of buildings concerning different external agents that may undermine or attack their heritage value integrity. Some of these studies focus on analyzing vulnerability due to the use and maintenance of these heritage buildings [37]. 

Others base their research on the impact of singular atmospheric events, disasters such as earthquakes, or due to the action of coastal phenomena, flood-prone areas, etc., [38-40]. 

However, in no case have studies been conducted on the objective and quantitative quantification of the vulnerability of unprotected buildings located in predominantly heritage-protected urban areas, which, to improve their energy efficiency, are transformed and modified entirely through techniques and various constructive processes of overlaid exterior coatings, such as ventilated facades, ETICS, or any other material alien to their original configuration and composition. 

The present research addresses methodically, uniquely, and originally the problem or question of evaluating these buildings and their original constructive vulnerability and configuration concerning these invasive exterior energy rehabilitation techniques, creating a replicable prototype extending to the urban core in which they are inserted. Through this methodology and its results, it is possible to propose and specify the most suitable intervention techniques or systems for their energy rehabilitation, safeguarding the heritage value of the urban fabric as a whole of which they are part. 

 

Finally, the conclusions of the case study have been presented to the corresponding administrations and they have requested the application of the prototype in a new area, through a contract. Therefore, it can be concluded that the work has been very successful, and the methodology will be able to be applied and improved in a new case study, in an expansion with somewhat different characteristics than the one studied, with a greater number of buildings and variety. of architectural styles. From this project, new research contracts have emerged with various public administrations, being aware of the problem of the alteration of the urban image, which have realized that they lack a tool to be able to manage the limitations in this type of interventions. Therefore, we consider that the prototype is original, innovative, objective and replicable.