28
C. Rivero-Camacho et al.
To give a visual idea of the proportion of the impacts, the table is accompanied by
a graph. It can be seen that the biggest impacts are those generated by the materials
necessary for the execution of the works, and, as is to be expected, the sources of
consumption are found in the construction stage.
There is also an important focus on the hours of machinery and manpower required
in the renovation programmed in the year 70 of the BLC. This is related to the increase
in the CDWs generated by these interventions, since, at this age of the building, the
renovation works are due to the repair works of structures. In addition, these results
can be related to those presented in the research of Alba et al. [97] in which the
economic and environmental profitability of this type of intervention is evaluated
in relation to the damage to the building. If these results are analysed in detail, the
first thing to be observed is that the consumption of resources in the construction
stage is double that is required in the renovation stage 70. However, when we look
at the CDWs, we see that they increase almost 10 times more in renovation than
those generated in construction. This translates into a notable increase in the impact
caused by the management of the CDW generated associated with the machinery.
In the case of demolition, the low impact is more evident, since no material
resources are consumed, the only impact associated with this stage of the building
being the machinery, both for the execution of the demolition and for the subsequent management of the CDWs generated. It should be remembered that CDWs
have no material environmental impact because this was accounted for when the
building was incorporated as a new material. When the materials are removed from
the building, already considered CDW, only impacts are associated with it because
of the machinery necessary for its management and thus, avoiding duplication in the
quantification of impacts.
Finally, the stage of renewal at 20 years stands out as the stage of least impact,
around 1%. In the case of the renovation after 20 years, these reduced impacts are
due to the fact that the actions in the building only intervene in the replacement of
the air conditioning and sanitary hot water generation equipment (DHW), works of
little entity if compared to the rest of the stages.
The impacts associated with materials and CDWs are discussed in more detail
below. To this end, Fig. 11 shows the classification of the main families of materials,
the material resources consumed and the CDWs generated throughout the entire BLC.
The total environmental impact generated by each type of material has been calculated. The quantification has been carried out by measuring the weight of material
consumed per surface area of the house built for each case (kg/m
2 ).
Figure 11 shows how more CDW is generated than materials consumed in almost
all families of materials. This is due to the fact that, in the renovation stages, it must be
taken into account that all the materials incorporated will be to replace other damaged
ones; therefore, the quantities generated of CDW are quite close to the materials
consumed. To these amounts, they must add the losses inherent in the execution of
the work and, most importantly, the increase in CDW due to the packaging of the
materials, the main reason why the final balance between materials and CDW is
greater in quantity than the total CDW in the BLC. Finally, the demolition stage, a
phase in which no materials are consumed, only CDW are generated, which are the
C. Rivero-Camacho et al.
To give a visual idea of the proportion of the impacts, the table is accompanied by
a graph. It can be seen that the biggest impacts are those generated by the materials
necessary for the execution of the works, and, as is to be expected, the sources of
consumption are found in the construction stage.
There is also an important focus on the hours of machinery and manpower required
in the renovation programmed in the year 70 of the BLC. This is related to the increase
in the CDWs generated by these interventions, since, at this age of the building, the
renovation works are due to the repair works of structures. In addition, these results
can be related to those presented in the research of Alba et al. [97] in which the
economic and environmental profitability of this type of intervention is evaluated
in relation to the damage to the building. If these results are analysed in detail, the
first thing to be observed is that the consumption of resources in the construction
stage is double that is required in the renovation stage 70. However, when we look
at the CDWs, we see that they increase almost 10 times more in renovation than
those generated in construction. This translates into a notable increase in the impact
caused by the management of the CDW generated associated with the machinery.
In the case of demolition, the low impact is more evident, since no material
resources are consumed, the only impact associated with this stage of the building
being the machinery, both for the execution of the demolition and for the subsequent management of the CDWs generated. It should be remembered that CDWs
have no material environmental impact because this was accounted for when the
building was incorporated as a new material. When the materials are removed from
the building, already considered CDW, only impacts are associated with it because
of the machinery necessary for its management and thus, avoiding duplication in the
quantification of impacts.
Finally, the stage of renewal at 20 years stands out as the stage of least impact,
around 1%. In the case of the renovation after 20 years, these reduced impacts are
due to the fact that the actions in the building only intervene in the replacement of
the air conditioning and sanitary hot water generation equipment (DHW), works of
little entity if compared to the rest of the stages.
The impacts associated with materials and CDWs are discussed in more detail
below. To this end, Fig. 11 shows the classification of the main families of materials,
the material resources consumed and the CDWs generated throughout the entire BLC.
The total environmental impact generated by each type of material has been calculated. The quantification has been carried out by measuring the weight of material
consumed per surface area of the house built for each case (kg/m
2 ).
Figure 11 shows how more CDW is generated than materials consumed in almost
all families of materials. This is due to the fact that, in the renovation stages, it must be
taken into account that all the materials incorporated will be to replace other damaged
ones; therefore, the quantities generated of CDW are quite close to the materials
consumed. To these amounts, they must add the losses inherent in the execution of
the work and, most importantly, the increase in CDW due to the packaging of the
materials, the main reason why the final balance between materials and CDW is
greater in quantity than the total CDW in the BLC. Finally, the demolition stage, a
phase in which no materials are consumed, only CDW are generated, which are the