Landlord–Tenant Dilemma: How Does the Conflict Affect the Design of Building Energy Systems?

Round 1

Reviewer 1 Report

The article describes so-called „landlord-tenant dilemma”. The authors analyze how the renovation decision of the building owner differs between owner-occupied and rented buildings.

Abstract correctly describes what the problem is, what the literature says about it, and what the article authors' research results are.

Table 2 provides interesting way of representing different research disciplines related to the landlord-tenant dilemma.

The research method is very well and logically described.

Tables and Figures are clear and very professionally and logically described.

Please, explain why the optimization model in form of a mixed integer linear program (MILP) was chosen, what are its advantages?

From Figure 3 to Figure 7, I don't understand why the Status of building envelope is given? Almost all the data is zero. Please explain.

From Figure 3 to Figure 7 we can see that the "window" parameter always has a value of zero. Why?

In Table A2 we can read that investment for “windows” is equal to -226.8908 €. Please explain this phenomenon in more detail. Is this a parameter that is not invested in in Germany? If so, why? There are windows that are more or less energy efficient.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This is a study of building costs and energy consumption that consider landlord-tenant attitudes. Overall, the logic of the study is clear and complete. Here are some of my recommendations:

1. It is recommended to complement the complete research technology roadmap. 

2. Please provide a brief description of the overall renovation and rent situation for landlords and tenants in the target area to better understand the cost concept. 

3. Extract the core innovation points of this article. 

4. To calculate the overall input and output of each scenario, clearly list the parameters and indicators. 

5. This article has a lot of policy-level content, so the optimization process is recommended to provide policy-level thinking.

Minor editing of English language required

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

In the first round of review, it is suggested to add a research technology roadmap. The authors may not get my point. It means to add a flowchart of the methods used in this research to help understand how and which research technologies were adopted and what is the research objective.

Author Response

Thank you very much for clarifying your comments. We have now included a further figure in Section "1.3 Contributions "showing our research approach, including: 
- Research question
- Method: MILP optimization, including the two objective functions and decision variables 
- Method application: use case & results section
- KPIs 
Also, you find a short text describing the overall structure of our study.  

Best regards

Round 3

Reviewer 2 Report

It is acceptable now.