Carbon Emissions of Construction Processes on Urban Construction Sites

Round 1

Reviewer 1 Report

Thank you for allowing me to review this paper. It is an interesting paper as it aims to include onsite constructions impacts. 

The background knoweldge can somehow be imroved. 

The authors did not clarify the goals clearly. Also, the link between the paper deliverables and goals to acheive carbon neutrality needs to be cleared. A "balancing method" seems quite vague and subjective in nature. 

Using Co2E must be defined. Are they the same as GWP?

Cement is a carbon intensive industry. This must be crosschecked. 

What is meant by digital twins?

Abbreviations must be defined before usage (RUMBA)

Author Response

Thank you for taking the time to review our suggested paper thoroughly.

• The background knowledge can somehow be improved.

We added additional sources and reworked the structure of chapter 1 to best summarize the existing scientific progress in the field.

• The authors did not clarify the goals. Also, the link between the paper deliverables and plans to achieve carbon neutrality needs to be cleared. A "balancing method" seems quite vague and subjective in nature. 

As you pointed out, the abstract and discussion were not precise enough; these were adapted to define the aim of the article, which are: to determine the processes that cause co2 emissions, categorize them according to existing standards, and to adapt them in such a way that they meet the requirement of being able to represent construction site processes as accurately as possible and to be able to use the various existing data.

• Using Co2E must be defined. Are they the same as GWP? 

The following footnote has been added: an artificial unit that accounts for the global warming potential of any desired compound of substances by converting the substances’ resulting global warming potential into a mass of carbon dioxide that has an equal global warming potential as the compound.

• Cement is a carbon intensive industry. This must be crosschecked. 

The source cited has derived the relative distribution of GHG emissions from materials and energies per meter of the tunnel. These citated figures were crosschecked and described more precisely in the paper

• What is meant by digital twins?

The following definition was added to the text: "[...] which represents a virtual representation of buildings over their life cycle [...]"

• Abbreviations must be defined before usage (RUMBA)

The abbreviation for RUMBA was added to the text (and translated into english), and other abbreviations were also checked for their existing definition within the paper.

Also, we reviewed our article regarding scientific English language and grammar,  cohesiveness, logic and unambiguos presentation of the results, and especially the connection between our findings and existing literature.

Reviewer 2 Report

This paper suggests a balancing method with a defined set of system boundaries to single out the emissions which occur in the sphere of construction industry. Moreover, through the comparison of case results, it is concluded that the transportation is the biggest cause of emissions. This manuscript is rich in content. However, there are several problems that must be discussed carefully.

(1) In section 1.2, there is no reason to compare carbon emissions in different life cycle stages of different locations, rather than the life cycle stages of the construction industry.

(2) In section 2.2, “Diesel bills were available for one site but not complete, so diesel consumption had to be estimated for all sites” is mentioned in this section, so how to estimate all sites?

(3) In section 3, since renovation and demolition occur in different time periods, and other conditions such as construction methods will change, why is the method proposed in this paper still considered suitable to cover the status quo?

(4) There are some format errors in this paper. The serial number is confused, for example, 1.1.1 is missing,1.1.3 is repeated, etc.

Author Response

Thank you for taking the time to review our suggested paper thoroughly.

• In section 1.2, there is no reason to compare carbon emissions in different life cycle stages of different locations, rather than the life cycle stages of the construction industry.

We completely reworked the section with your feedback in mind.

• In section 2.2, “Diesel bills were available for one site but not complete, so diesel consumption had to be estimated for all sites” is mentioned in this section, so how to estimate all sites?

We clarified the calculation method (which was described below and linked the description to figure 2.

• In section 3, since renovation and demolition occur in different time periods, and other conditions such as construction methods will change, why is the method proposed in this paper still considered suitable to cover the status quo?

We changed our contemplation to a more suitable one where we look at the construction sites individually, all of them as they are currently conducted.

• There are some format errors in this paper. The serial number is confused, for example, 1.1.1 is missing,1.1.3 is repeated, etc.

We checked the formatting in this paper and updated all the references in word file.