8
C. Rivero-Camacho et al.
point of view of the proposed renovations, they are considered part of the maintenance
of the building, so that the maximum performance of the original building can be
obtained, prolonging its useful life in a moderate way. With this in mind, every time
the building is renovated, the improvement of its energy efficiency will be taken into
account. This will be motivated by the changes, both in their constructive solutions
and in their installations, being these modernized with respect to the original ones,
with the consequent change in the patterns of consumption.
In order to establish the optimal moment when building renovations will be considered, the standard UNE-15459-1-energy efficiency of buildings is taken as a reference. Procedure for the economic evaluation of the energy systems of buildings BLC
assessment method. Inputs and outputs for the calculation of the building’s energy
efficiency [54]; and the UNE-15686-1-useful life of materials [55]. These must be
complemented with the Technical Building Code in Spain [56], which establishes,
based on Eurocode EN-1990, that residential buildings must be designed for a duration of 50 years or 100 years if they are for public use. For this reason, the study is set
at 100 years, considering an increase in the useful life of the building due to proper
maintenance and renovations. Based on these reference standards, it is estimated that
the renovations will take place when it is 20, 40 and 70 years old, on a cumulative
basis, adapting the items included in each work to the duration of the various installations and components of the building. Since the installations are the elements that
require most frequent renewal, they will be intervened in each renewal project. From
40 years old and onwards, the replacement of the woodwork and the relevant repairs
to the enclosure are included. The latter will be repaired again 30 years later; in the
renovation at 70 years old, where together with the previous elements mentioned,
structural repairs will be included, as well as the installations that are more difficult
to replace, such as the sewerage system.
With all that is set out in this section, and the considerations of durability of the
materials presented in the Larralde research [57], the longitudinal limits of the scope
of this study are established, which give rise to the designed BLC, which is detailed
in Sect. 4 of the case study. In summary, the BLC begins with the urbanization and
construction of the building, which would include all the environmental impacts
associated with the extraction, manufacture, transport and installation of the materials. Once the building is occupied, the 100-year use phase begins. This stage will
be subdivided into four periods of use due to the different renovation works planned
at 20, 40 and 70 years old. Finally, demolition is considered at 100 years old, when
it is estimated that the building will no longer be fit for habitation.
(b) System boundaries
Once the time limits have been established, the limits of the BLC are set in terms
of the factors to be taken into account in this study as opposed to those that would not
be quantified for the environmental assessment. These are its transverse boundaries,
which will form the separation between our system and other production sectors, such
as the furniture industry, household appliances, construction materials manufacturing
and waste treatment plants. This will be essential to avoid double quantifications and
overlaps between cycles—building–surrounding relationship.
C. Rivero-Camacho et al.
point of view of the proposed renovations, they are considered part of the maintenance
of the building, so that the maximum performance of the original building can be
obtained, prolonging its useful life in a moderate way. With this in mind, every time
the building is renovated, the improvement of its energy efficiency will be taken into
account. This will be motivated by the changes, both in their constructive solutions
and in their installations, being these modernized with respect to the original ones,
with the consequent change in the patterns of consumption.
In order to establish the optimal moment when building renovations will be considered, the standard UNE-15459-1-energy efficiency of buildings is taken as a reference. Procedure for the economic evaluation of the energy systems of buildings BLC
assessment method. Inputs and outputs for the calculation of the building’s energy
efficiency [54]; and the UNE-15686-1-useful life of materials [55]. These must be
complemented with the Technical Building Code in Spain [56], which establishes,
based on Eurocode EN-1990, that residential buildings must be designed for a duration of 50 years or 100 years if they are for public use. For this reason, the study is set
at 100 years, considering an increase in the useful life of the building due to proper
maintenance and renovations. Based on these reference standards, it is estimated that
the renovations will take place when it is 20, 40 and 70 years old, on a cumulative
basis, adapting the items included in each work to the duration of the various installations and components of the building. Since the installations are the elements that
require most frequent renewal, they will be intervened in each renewal project. From
40 years old and onwards, the replacement of the woodwork and the relevant repairs
to the enclosure are included. The latter will be repaired again 30 years later; in the
renovation at 70 years old, where together with the previous elements mentioned,
structural repairs will be included, as well as the installations that are more difficult
to replace, such as the sewerage system.
With all that is set out in this section, and the considerations of durability of the
materials presented in the Larralde research [57], the longitudinal limits of the scope
of this study are established, which give rise to the designed BLC, which is detailed
in Sect. 4 of the case study. In summary, the BLC begins with the urbanization and
construction of the building, which would include all the environmental impacts
associated with the extraction, manufacture, transport and installation of the materials. Once the building is occupied, the 100-year use phase begins. This stage will
be subdivided into four periods of use due to the different renovation works planned
at 20, 40 and 70 years old. Finally, demolition is considered at 100 years old, when
it is estimated that the building will no longer be fit for habitation.
(b) System boundaries
Once the time limits have been established, the limits of the BLC are set in terms
of the factors to be taken into account in this study as opposed to those that would not
be quantified for the environmental assessment. These are its transverse boundaries,
which will form the separation between our system and other production sectors, such
as the furniture industry, household appliances, construction materials manufacturing
and waste treatment plants. This will be essential to avoid double quantifications and
overlaps between cycles—building–surrounding relationship.