14
C. Rivero-Camacho et al.
the EF [2, 16, 80] and the scheme shown in Fig. 6. The summary of all the equations
used for the calculations is shown in Table 1.
Firstly, indirect resources have been defined, which in traditional construction
budgets correspond to manpower, materials and machinery. These cause impacts
on the work through the energy consumption of the machinery used on site (fuel or
electricity), the impact of the workforce (through the quantification of working hours)
and the consumption of construction materials (during their manufacture, transport
and installation).
1. Manpower
Next, the analysis of the impacts generated by the workers on the site is carried out,
generation of Municipal Solid Waste (MSW) and food consumption. The mobility
of the operators to the work site or place of work is excluded in order to adjust the
methodology to the proposal in the UNE-EN 15978 [58], for the Life Cycle Analysis
(LCA) of the building. The EF produced by the workers’ food is considered the
worker’s energy source and is obtained from Eq. 1 in Table 1.
The footprints are generated according to the type of food (meat: EF of pastures;
fish: EF of productive sea; cereals: EF of farmland), with the natural productivity
and equivalence factor of each productive territory. The crop equivalency factor is
2.51; for pasture, it is 0.46; for forest, it is 1.26; for sea, it is 0.37; and for direct area
of occupation, it is 2.51 gha/ha [83]. All foods will also produce an energy footprint,
due to the energy consumed in their transformation. The equivalency factors used
[11] are implicit in the calculation of EF (EF/person and year) for each country, see
Table 2. It has been taken into account that breakfast and lunch (which are made on
site) represent approximately 60% of the daily diet of an adult [84]. To obtain the
footprint of the MSW, an average generation coefficient per worker and the emission
factor of their treatment are used (Eq. 2 in Table 1).
2. Materials
To obtain the EF of each product or building material used in the project, first
the weight of these is obtained, and the CO 2 emissions contained in each kg of
material are applied according to the LCA databases. Once all the CO 2 emissions of
each material have been obtained, Eq. 3 in Table 1 is applied to obtain the EF. Up
to this point, the environmental impact of the materials during the life cycle of the
cradle to door is covered. To evaluate the A4 aspect of the UNE-EN 15978 standard
[58], an analysis of the transport of the material is also carried out, establishing
approximations of the distance covered by the means of transport, see Table 3 [19].
The first thing to take into account is the means of transport to be used; in our
case, it is by truck, whose capacity is defined in tons and average consumption of
diesel, also taking into account the CO 2 emissions for each litre of fuel consumed. The
second aspect to be considered is the distance to the work site from the factory and/or
the warehouse of each material; taking the following approximations, in Andalusia,
it is considered that most of the materials are manufactured in that area, for which
the average distance is 250 km. In the specific case of concrete, a maximum distance
of 20 km will be considered, according to the considerations of EHE-08, Art. 71,4.
C. Rivero-Camacho et al.
the EF [2, 16, 80] and the scheme shown in Fig. 6. The summary of all the equations
used for the calculations is shown in Table 1.
Firstly, indirect resources have been defined, which in traditional construction
budgets correspond to manpower, materials and machinery. These cause impacts
on the work through the energy consumption of the machinery used on site (fuel or
electricity), the impact of the workforce (through the quantification of working hours)
and the consumption of construction materials (during their manufacture, transport
and installation).
1. Manpower
Next, the analysis of the impacts generated by the workers on the site is carried out,
generation of Municipal Solid Waste (MSW) and food consumption. The mobility
of the operators to the work site or place of work is excluded in order to adjust the
methodology to the proposal in the UNE-EN 15978 [58], for the Life Cycle Analysis
(LCA) of the building. The EF produced by the workers’ food is considered the
worker’s energy source and is obtained from Eq. 1 in Table 1.
The footprints are generated according to the type of food (meat: EF of pastures;
fish: EF of productive sea; cereals: EF of farmland), with the natural productivity
and equivalence factor of each productive territory. The crop equivalency factor is
2.51; for pasture, it is 0.46; for forest, it is 1.26; for sea, it is 0.37; and for direct area
of occupation, it is 2.51 gha/ha [83]. All foods will also produce an energy footprint,
due to the energy consumed in their transformation. The equivalency factors used
[11] are implicit in the calculation of EF (EF/person and year) for each country, see
Table 2. It has been taken into account that breakfast and lunch (which are made on
site) represent approximately 60% of the daily diet of an adult [84]. To obtain the
footprint of the MSW, an average generation coefficient per worker and the emission
factor of their treatment are used (Eq. 2 in Table 1).
2. Materials
To obtain the EF of each product or building material used in the project, first
the weight of these is obtained, and the CO 2 emissions contained in each kg of
material are applied according to the LCA databases. Once all the CO 2 emissions of
each material have been obtained, Eq. 3 in Table 1 is applied to obtain the EF. Up
to this point, the environmental impact of the materials during the life cycle of the
cradle to door is covered. To evaluate the A4 aspect of the UNE-EN 15978 standard
[58], an analysis of the transport of the material is also carried out, establishing
approximations of the distance covered by the means of transport, see Table 3 [19].
The first thing to take into account is the means of transport to be used; in our
case, it is by truck, whose capacity is defined in tons and average consumption of
diesel, also taking into account the CO 2 emissions for each litre of fuel consumed. The
second aspect to be considered is the distance to the work site from the factory and/or
the warehouse of each material; taking the following approximations, in Andalusia,
it is considered that most of the materials are manufactured in that area, for which
the average distance is 250 km. In the specific case of concrete, a maximum distance
of 20 km will be considered, according to the considerations of EHE-08, Art. 71,4.