80
The EF_Total_ Urbanism is represented at 99% by the EF of energy associated with the
manufacture of building materials, i.e., the EF_emb_energy (98% in Algiers and 67% in Tipaza),
and to a lesser extent the conditioning energy (1.33% in Algiers and 32.1% in Tipaza). Indeed,
EF_opt_energy of the two wilayas is based on the emissions resulting from the combustion of
natural gas, which are about 10
3
kg for 1 MJ of gas burned. In addition, the emissions
associated with the generation and natural gas distribution to final users are negligible.
Similarly, the consumption of electricity has a low impact on the energy EF because the
emissions associated with this energy are mainly a result of the processing of natural gas and
roughly 10
3
kg/MJ.
The estimate of EF_emb_energy is based on both wilayas' real estate stock, and the
proportion of the mostly used construction materials. In the case of this study, only concrete,
brick and steel (concrete reinforcing bars) were considered and their proportions were
approximated using the specifications of some residential projects and individual house
construction.
Therefore, the EF_emb_energy is dependent on the quantity of these materials and the size
of the total housing stock of the two wilayas. It is worth noting the building materials' origin,
transportation patterns, the auxiliary materials as well as the construction techniques has not
been considered. Consequently, it is likely that the availability of such information would
affect the calculation. It could thus be an overestimate or an underestimate of the emissions
associated with the production of the three materials.
In both wilayas, the EF_c of dwellings is more important than that of individual houses. This is
mainly due to the number of this kind of habitation which is lower than that of the dwelling
projects. Indeed, at the scale of one unit, the construction of a single-family house (based on
quantitative reports) can generate more CO2 emissions and require a larger than dwellings.
However, these results should not be considered separately from the quality, origin and
manufacturing processes of the building materials.
The EF_built of the wilaya of Algiers is proportional to the number of dwellings and thus more
important compared to the wilaya of Tipaza. Indeed, figures 12 and 13 below, reveal that the
surface of the wilaya of Algiers is more than 32% urbanized compared to a low percentage of
12% in the wilaya of Tipaza, which has been increasing for both cities to reach about 45% for
the wilaya of Algiers and double the size for the wilaya of Tipaza (30%). The expansion of
urbanization differs between both wilayas. Though, the comparison betwwen the 2015 and
2022 (figures 14, 15) state outlines that the human expansion in both wilayas converge,
covering the western municipalities of Algiers (Zéralda) and the Eastern municipalities of
Tipaza (Koléa), which share the same boundaries.
However, the EF calculation, in this study- considers only the surface occupied by residential
buildings, thus, the interpretation doesn’t account for all the infrastructures comprised in
the “urban land” in each land occupation map (e.g., roads).
The EF_Total_ Urbanism is represented at 99% by the EF of energy associated with the
manufacture of building materials, i.e., the EF_emb_energy (98% in Algiers and 67% in Tipaza),
and to a lesser extent the conditioning energy (1.33% in Algiers and 32.1% in Tipaza). Indeed,
EF_opt_energy of the two wilayas is based on the emissions resulting from the combustion of
natural gas, which are about 10
3
kg for 1 MJ of gas burned. In addition, the emissions
associated with the generation and natural gas distribution to final users are negligible.
Similarly, the consumption of electricity has a low impact on the energy EF because the
emissions associated with this energy are mainly a result of the processing of natural gas and
roughly 10
3
kg/MJ.
The estimate of EF_emb_energy is based on both wilayas' real estate stock, and the
proportion of the mostly used construction materials. In the case of this study, only concrete,
brick and steel (concrete reinforcing bars) were considered and their proportions were
approximated using the specifications of some residential projects and individual house
construction.
Therefore, the EF_emb_energy is dependent on the quantity of these materials and the size
of the total housing stock of the two wilayas. It is worth noting the building materials' origin,
transportation patterns, the auxiliary materials as well as the construction techniques has not
been considered. Consequently, it is likely that the availability of such information would
affect the calculation. It could thus be an overestimate or an underestimate of the emissions
associated with the production of the three materials.
In both wilayas, the EF_c of dwellings is more important than that of individual houses. This is
mainly due to the number of this kind of habitation which is lower than that of the dwelling
projects. Indeed, at the scale of one unit, the construction of a single-family house (based on
quantitative reports) can generate more CO2 emissions and require a larger than dwellings.
However, these results should not be considered separately from the quality, origin and
manufacturing processes of the building materials.
The EF_built of the wilaya of Algiers is proportional to the number of dwellings and thus more
important compared to the wilaya of Tipaza. Indeed, figures 12 and 13 below, reveal that the
surface of the wilaya of Algiers is more than 32% urbanized compared to a low percentage of
12% in the wilaya of Tipaza, which has been increasing for both cities to reach about 45% for
the wilaya of Algiers and double the size for the wilaya of Tipaza (30%). The expansion of
urbanization differs between both wilayas. Though, the comparison betwwen the 2015 and
2022 (figures 14, 15) state outlines that the human expansion in both wilayas converge,
covering the western municipalities of Algiers (Zéralda) and the Eastern municipalities of
Tipaza (Koléa), which share the same boundaries.
However, the EF calculation, in this study- considers only the surface occupied by residential
buildings, thus, the interpretation doesn’t account for all the infrastructures comprised in
the “urban land” in each land occupation map (e.g., roads).