Comparative LCAs of Conventional and Mass Timber Buildings in Regions with Potential for Mass Timber Penetration

Round 1

Reviewer 1 Report

Congratulations for the very interesting work. The topic has interest and fits completely the aim of the SI. Below you can found some comments and suggestions.

 

Section 2.1.:

It could be briefly specified which MT products were considered for the MT buildings (CLT, glulam etc.), even it is shown in Appendix A. These elements results are cited in section 3.1. and its production sites in Table 2, but they are not introduced on section 2.1.

Lines 236-240:

This paragraph could be placed just after line 227, justifying the obtained values for mass contribution of MT presented between lines 214-225 and introducing the gypsum issue described in lines 228-235.

Lines 261-263:

This sentence could be placed in line 251, as an example of the increase of embodied carbon as the height of buildings grows.

Line 281:

The MT structural components (CLT and glulam) contributed 27-38 percent of the whole building embodied carbon, according to Figure 8.

Lines 296-300:

“While for the 18-story MT buildings (NE and SE regions) consumed more non-renewable fuels than the equivalent concrete design. (…) The transportation of MT was the driver in the A4 stage.”

This difference was drove by the A4 stage? If so, it could be specified the difference in distances covered for the transportation of concrete/steel and MT. Also, what can explain the higher consumption of non-renewable fuels for just 18-story buildings besides the locations specificities?

“The transportation distances of the CLT and glulam from the manufactures to the building site ranged from 332 km to 490 km [42].”

This range of distances is for NE and SE regions or all regions? 

I only understood what you meant by reading lines 372-380. Perhaps paragraph 295-300 can be made clearer or you can limit it to presenting the results obtained and leave the justification just in paragraph 372-380.

Lines 300-304:

A graphic showing the embodied energy (renewable and non-renewable) for each phase (A1-A5) could be added to support these information.

Lines 332-333:

“In all MT building 332 designs more carbon is stored then is emitted during production (A1-A5).”

This sentence can be deleted, as its content was already said in the previous sentence.

Lines 333-335:

As said for lines 300-304, a graphic could be added in results section to support these information. Same for lines 369-370.

Lines 352-355:

This sentence is the same as lines 238-240. It is preferable that it be kept in this section and deleted from section 3.1.

Lines 366-369:

Couldn’t understand the difference between these results (33-40 percent in the 8-story buildings, to 25-33 percent in the 12-story, and 27-35 percent in the 18-story) and the results shown in Table 6 (33-40 percent in the 8-story buildings, to 29-37 percent in the 12-story, and 25-33 percent in the 18-story).

Line 536:

DOI not found.

Author Response

Thank you very much for thorough review. I have responded in red under the comments/suggestions made.  I had some confusion when there where only line numbers used as a reference, but I have made every attempt to find the location and comment. Please see the attachment. 

Author Response File: Author Response.docx

Reviewer 2 Report

A well written paper with very relevant results on a very suitable theme for this journal. I recommend publishing these results with a minor revision.

On the abstract, the sentence “Total embodied energy was higher in all mass timber buildings compared to equivalent concrete.” must be rewritten to give better idea of what the authors meant to say.

Author Response

Thank you for the review.  I have changed the sentence in the abstract to read...

"Total embodied energy to produce, transport, and construct (A1-A5) materials was higher in all mass timber buildings compared to equivalent concrete."

Reviewer 3 Report

Comparative LCAs of conventional and mass timber buildings in regions with potential for mass timber penetration

 

The development of wooden construction based on modern materials such as LVL, Glulam or CLT is a beneficial alternative to traditional construction based on cement, steel, etc. Promoting the advantages of timber construction, especially in the context of the possibility of creating multi-storey buildings, is an important aspect of sustainable development. This is especially important in regions of the world where timber construction is still perceived as less attractive.

An important advantage of using wood-based materials in construction is the possibility of carbon dioxide accumulation, and thus reducing its emission to the atmosphere. The research results presented in the paper clearly confirm the advantages of wooden buildings in this respect. The authors rightly point out the need to improve wooden construction by searching for new construction and material solutions.

In the opinion of the reviewer, the paper is well written, the methodology and the presentation and analysis of the results do not raise any objections. 

Author Response

Thank you for your review. No changes were suggested by this reviewer.