# 196

Dear Paola Villalba, Antonio J. Sánchez-Garrido, Victor Yepes

I read your paper:

A review of Multi-Criteria Decision-Making methods for building assessment, selection, and retrofit

My comments:

1- In the abstract you say “assess the vulnerability of buildings.”

Why buildings should be vulnerable, unless after an earthquake of severe flooding or a tornado? Retrofitting a building 60 years old, probably still strong, although maybe it needs some repairs in the body or in its pipes, but normally they are old but not vulnerable, unless it has been severely damaged by war, fire or flood. In many cities you can see a beautiful high tower on an old first floor, and making a beautiful contrast.

I really don’t see the link between an old building and society, unless it is a ruin, home for rodents and insects. In my understanding any building must be linked to society, health and environment, regarding electricity efficiency, appropriate pipes, removing asbestos or improving the heating

2- I do not think that you must perform a bibliometric search to look for criteria. An engineer or architect can tell you what is needed; for a particular property, however, this search may be useful to complete the assessment of these two experts, who in addition, are probably more updated of new trends, materials, necessity to integrate with the environment, health, economics, law and municipal regulations, weather, earthquakes, structural conditions, etc., than exiting publications.

Remember that in the last 40- or 50-years fundamental concepts have changed, for instance schools’ organization, hospital new services, lighting, heating, water conservation, forestation of cities, new structures for offices, transportation, insulation materials, paints, earthquake resistance, nearby highways, etc., and of course, considering that there is never a structure identical to another.

3- In page 8 you mention using pair-wise comparison method. In my opinion that procedure, that allows criteria pair preference, is the most senseless method used in MCDM, and has been discussed, and rejected by most researchers since the late 80s. It is OK to establish preferences on a criterion over another, we do that hundred of times everyday, but it is absurd to put a quantitative value for that preference, especially with subjective criteria, as cultural gain and using GIS

4- In page 7 you used these two words ‘Anti-Corruption measures’ related to schools. Sorry, but I unable to find a social issue and corruption linked to education, unless you are talking about sociology.

5- Page 7 “achieve seismic and energy efficiency”

I understand energy efficiency but seismic efficiency? Wouldn’t be better to talk about seismic resistance?

6- Page 8 “Pairwise comparison methods are used to determine the weight of different criteria based on decision makers’ knowledge; the Analytic Hierarchy Process (AHP)”

Redetermine? Based on intuitions? I would say that the trade- ffs obtained, not weights, from AHP, only represent what is in the mind and mood of the DM, and after they are mandatorily “corrected” by a formula ,if they do not produce a transitive matrix. Very mathematical indeed!

There not feedbacks in ANP, that was an assumption that Saaty never explained.

7- Page 9 “Weights were generated by averaging the ANP and AHP models”

This seems incorrect because you cannot compute an average of two different things as AHP and AN P, because the first only works with independent criteria and only in a hierarchical top-down approach, while ANP can work with any type of criteria and in a y direction. The first follows line of operations while the second follows networks

8- Page 9 “Therefore, 29 articles included sensitivity analyses through the variation of criteria weights”

And this is incorrect because variation of criteria produced by weights do not participate in the evaluation of alternatives, that mostly depend on the discrimination in each criterion, something not related to weights

9- Page 9 “Several studies have combined pairwise comparison MCDM methods with fuzzy methodologies to improve the accuracy of decision-making processes: the hierarchical analytic fuzzy method using fuzzy triangular numbers”

Fuzzy is a very good technique when used wisely, which is not the case of AHP, since the weights are invented values, and what fuzzy does is to have the average of those values which does not have any utility in real projects. They only represent the coherence of throe DM

10- In Figure 6 page 11 it is shown a Venn diagram showing the intersection of three criteria. This is the correct way to work, however, the diagram should have as many circles as the number of criteria, and the intersection of possibly most of them, determines the common space where are all feasible solutions of the problem. In this case the warped triangular with 17% is the common space for these three criteria. This same representation is very commonly used to illustrate the mutual interdependency in sustainability, linking Society, Environment and Economics. I like very much your contribution on this aspect

11- Page 11 “The literature review underscores the necessity of achieving consensus within the scientific community regarding the criteria to be evaluated across various dimensions”

Agreed, albeit I recommend not using the word ‘dimension’, because it has another meaning, especially in rank reversal, where it is equivalent to number of alternatives

12- Page 12 “Regarding building retrofitting, the current approach emphasizes the integration of four dimensions: safety, economic, social, and environmental”

I wouldn’t put it as a new approach since researcher and practitioners have been inputting the four of them since 1960.

These are my comments, I hope they can help

Nolberto Munier