Current Status of Old Housing for Low-Income Elderly Households in Seoul and Green Remodeling Support Plan: Economic Analysis Considering the Social Cost of Green Remodeling

Round 1

Reviewer 1 Report

This is an interesting paper analyzing the status and problems of old housing of low-income elderly households in Seoul, South Korea, and the economic feasibility of Green Remodeling in terms of improving the health, safety, and energy of elderly households while considering social cost. Both the methodology and approach presented would be interesting for readers working in the field, and the conclusions derived from the study are also offering very useful insights. I do not have any further comments or suggestions for improvement of this paper. An excellent contribution to knowledge in the associated field.

Author Response

Thank you for your time for reviewing our manuscript.

Reviewer 2 Report

The paper deals with the important issue of old housing of low-income families, focusing the improvement of energy performance, health and safety conditions as well as the economic feasibility of Green Remodelling, which is a growing area of the investigation in the main cities of the world. The approach is used to investigate the case of a single family house in Seoul, Korea. I have listed the following comments for the Authors and I would expect them to be addressed before the paper is published.

- The abstract should include some quantitative results, highlighting the main findings.

- The information of the climate region is not addressed in the paper. A short analysis of this topic is recommended.

 - Once airtightness of old housing is one of the improvements in the green remodelling “package”, please make clear what are the house air permeability results of the existing model. Furthermore, explain how the ACH50 was quantified, attaining three times less (Table 8) in the improved model.

- Authors defined the house nº4 (1 storey house) for this investigation. However, the most of Low-income Elderly Households are living in multi-storey buildings (neighbourhoods in the main cities), due the low rents compared with a single house. How differ the results would be ? Have any results in this type of buildings?

 

TYPO ERRORS AND FORMATTING TEXTS

- line 392 – bracket is missing

- Table 8 – “CMH” is not defined

- Energy units Wh/㎡y, or kWh/㎡y -> dot (”.”) is missing. Example: lines 398/401/406/408

- line 541 – an extra dot after “safety”

Author Response

First of all, thank you for your detailed review opinions. Below please find our point-by-point response to your comments and suggestions:

 

1) [Line 7-16] The abstract emphasized the main findings and included quantitative results.

 

2) [Line 352-359] Regional climate information was added to 4.1. Analytical procedures and methods as follows:

For weather data of ECO-2, standard profiles were brought in from ECO-2 central server to allow selection of average data for 66 regions in Korea. Basically, Korea has distinct climatic characteristics of four seasons: spring, summer, fall, and winter. Weather data of ECO-2 provide monthly average values calculated based on TMY (Typical Metrical Year Data) weather data, which monthly average ambient temperature and monthly average solar intensity according to the incident angle by bearing. The target building of this study was located in Seoul. Accordingly, in ECO-2, Seoul was set out of 66 areas in Korea and analysis was conducted.

 

3) In the existing model, residential building performance standard commonly used in the domestic building energy efficiency rating evaluation was applied for airtightness. Accordingly, in [Air tightness] – [Sources and Assumptions] of Table 7, the following was added: In ECO-2, a domestic building energy evaluation program, for air tightness of residential buildings, ACH50 6.0 times is to be applied in the preliminary certification. Field measurement result is to be applied in the main certification. For this building, the preliminary certification standard was applied.

In Korea's building energy performance evaluation, when windows are replaced, air tightness is generally defined as ACH50 3.0. As a related document, the airtight performance standard of buildings (KIAEBS, 2013) recommends 3.0 ACH50 or less for energy-saving buildings. Air tightness measurement result of 3.29 ACH50 was derived even in the case where windows were replaced (Kim et al., 2020). Accordingly, in Table 8, [Air tightness] – [Sources and Assumptions], "for three times (ACH50), the phrase of air tightness of ACH50 3.0 times that is generally applied after replacing windows in Korea is to be applied" and references [10, 42 are added.

 

4) As mentioned in Section 3.2, remodeling some spaces in rental buildings is not considered an easy task. 'Rent increase' after remodeling may cause problems such as relocation of existing tenants (low-income elderly households). In addition, tenants in multi-story buildings are requesting support for moving to low cost public rental apartments or rent (living expense) support. Therefore, although this study only analyzed low-rise houses of self-owners, it is a necessary to expand the scope of application of this study regarding your inquiries raised in the review. Additional data collection and study will be conducted later to verify it. In the last paragraph of the conclusion, related contents were added mentioning the limitation as follows.

[Line 631-637] “Finally, in this study, a concept of a support policy was suggested through GR to improve old housing of small-scale low-income elderly people. However, this study has a limit in that the analysis was made only for detached houses. It is necessary to increase the reliability of the analysis result by increasing the number of buildings to be analyzed in the future. In addition, to improve housing of the poor according to various housing types in Korea and ages, more diverse types of measures to improve housing for common people are needed in the future.”

 

5) TYPO ERRORS AND FORMATTING TEXTS : All modifications have been completed.

 

Thank you for your time for reviewing our manuscript.

 

Author Response File: Author Response.pdf