A Biophilic Design Approach for Improved Energy Performance in Retrofitting Residential Projects

Round 1

Reviewer 1 Report

The topic of the article is relevant and may be of interest to specialists and researchers in the fields of construction, energy and optimal use of resources. This research provides a better understanding of the need to renovate existing buildings but does not clearly state what is new to what has been previously researched. The article deserves attention, however, as comments and recommendations, several points should be noted:

The authors should indicate what the scientific novelty of the work is - it should be indicated more clearly and in detail.

Also the authors should justify in more detail the choice of design and architecture of the building chosen for the study.

 

The abstract states:

The building sector is the greatest threat to climate change; and existing building stock is accounted as the major contributor in total energy consumption and related emissions. Considering the small rate of replacement or addition of building stock by energy-efficient new-builds each year, an increasing amount of attention is paid to improving energy performance in existing buildings, especially houses, since the residential sector (households) has contributed 25-27% to the total en-ergy consumption since 1995.  

The authors refer to Sydney, Australia, or the world in general?

 

This study attempts to bridge this gap by introducing a BD approach to retrofit buildings to improve their performance. Proposed design approach is demonstrated through an urban case study from Sydney, Australia.  

The authors do not really demonstrate improvement through biophilic design but through quantified architectural solutions. To be more accurate, the authors should have proposed different solutions to improve energy efficiency, evaluated these solutions on a biophilic value scale and then demonstrated that the conjunction of both is an improvement for humans.

 

The building performance is improved in terms of daylighting, ther-mal comfort and reduced energy consumption, additionally enhancing HNC

Only the objective improvements are shown, nothing about comfort is demonstrated. A better relationship between interior and exterior is established by having larger openings and therefore more light.

 

Specifically, in a time of a global pandemic due to COVID-19, essential need for improved indoor environmental condi-tions and contact with nature are advocated across the globe. In this light, the findings from this study are significant to direct the current sustainable design practice to foster biophilia in the built environment

Throughout the article, the importance of contact with nature during the pandemic is only mentioned in the abstract and conclusions. There is no reference to any work that evidences improvements in comfort. As an example:

https://doi.org/10.1016/j.buildenv.2021.108440

https://doi.org/10.1016/j.enbuild.2018.12.014

 

lines 55/56  BD principles are based on the use of natural elements and processes within built environment elevating a sensory connection to nature.

lines 55/56  the authors do not describe natural uses and processes but constructive processes. Line 68 also states that the objective of this research is to present a BD approach that can achieve energy efficiency in a retrofit design but the variables worked and tested by software are of a constructive technical nature.

For the present research, daylight, air and plants have been selected as the main biophilic elements to renovate the urban terraced house but neither ventilation nor the landscape project in the reduced plot of the case study is discussed.

For a better understanding of the actions carried out in the rehabilitation of spaces, the floor plans of the study house should always be the same oriented in Table 2 and Figure 5. Readers who are not architects or engineers will better understand the changes.

 

In lines 361 to 364, it is stated that “It has been shown that (Table 4) by implementing biophilic 361 elements – daylight, air, and plants in particular retrofitting phases, the house performs 362 better in terms of daylighting, thermal comfort, along with a slight improvement in over-363 all energy consumption.”

User comfort has not been evaluated with tools such as Givoni's, Fanger's and ASHRAE 55. See https://doi.org/10.1080/09613218.2021.1971060

In Figure 7 the authors represent the intervention or phase 6 as a greenhouse or solar gallery but do not tell how it has been introduced in the simulation and do not quantify the benefits in winter and problems in summer. Evidence should be provided.

 

lines 476 to 479. it is admitted that the scope of this study has not investigated the empirical evidence of user experience to understand the health outcomes of the BD approach. But line 18 of the abstract enunciated that biophilic design practice focuses on sensory expression rather than building performance. How is this inconsistency resolved?

Further at line 478 The statement that the findings of the existing literature could be useful for making assumptions about its benefits is not relevant.

 

The statement in the first paragraph of the conclusions, lines 497 to 501, is not sufficiently justified.

COVID appears for the second time in the conclusion in a very stilted way. No recent studies are cited in the entire document.

In the conclusions, different lines of research are enunciated but there are no solid conclusions derived from the rehabilitation of the house or from the tests carried out, the proportions of the openings or their orientations.

In general, the presented article leaves a positive impression, and after eliminating these comments and taking into account the recommendations made, the presented article can be recommended for publication in the journal Sustainability.

Author Response

Thanks for your time and effort to review our paper. Please find our answers in the attached document.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript deals with an interesting topic of nature-oriented design of buildings. It is well organized, properly structured and understandable.

Nevertheless, several minor changes seems to be necessary.

lines 176-179: why natural materiarls (stone, wood, etc.) were not included?

Table 1 - in several cases figures covered the text - and it is unreadable

line 270-271: "new space layout is suggested, changing the toilet position on the ground floor from" - what about costs of such intervention(s)?

lines 315-316: "percentage of humidity is 57%." - "relative humidity" sounds better, I suppose.

Figure 6: Heating/Lighting and Occupancy profiles - lines are inclined. Shouln't they be vertical, instead? For example: Lighting at 7:00 - Percentage = 0, but at 7:30 percentage = 0.5? or 0 till 7:59?

lines 381-383 - how do you define "energy intensity"?

 

For consideration only - line 31-32 "It is evident that the building sector is the greatest threat to climate change due to being responsible for 40% of global energy consumption." 

In my humble opinion, the most problematic is depletion of fossil energy resources, while as to the sources of the greenhouse effect - science is still developing and we still have different theories, such as here: 

https://www.nature.com/articles/news001207-6

https://www.nature.com/articles/news.2010.519

Author Response

Thanks for your time and effort to review our paper. Please find our answers in the attached document.

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript attempt to retrofit an existing terrace house in Sydney (Australia)  context by using a biophilic design approach. Good efforts have been done in this manuscript; however, this study employed many variables such as ( daylight, air, plants, and water used in buildings in form of window, skylight, clerestory, green wall, vegetation, water wall, and constructed water body) which is very difficult to take into account all this for optimization method. In addition, the main issue in my point of view is that the proposed scenarios are not clear based on what assumes the values such as the window to wall ratio (WWR), the U value of external envelope, skylight size (please explain in detail). But still a good try to incorporate the biophilic design as an essential approach to retrofit the buildings.

Author Response

Thanks for your time and effort to review our paper. Please find our answers in the attached document.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The presented article leaves a positive impression