Civil Engineering Reference
In-Depth Information
energy consumption is calculated according to the Cumulative energy demand
method. In particular, the following mid-point indicators were selected, since they
are widely known and applied by LCA experts:
• Cumulative energy demand (CED), distinguished in:
- Non-renewable primary energy (including energy resources used as raw
material)
- Renewable primary energy (including energy resources used as raw material)
• Global-warming potential (GWP)
• Depletion potential of the Ozone layer (ODP)
• Acidification potential of land and water (AP)
• Eutrophication potential (EP)
• Photochemical ozone creation potential (POCP).
Table
5
shows the outcomes of the above-described LCIA performed for the
existing
LH
(Scenario
1)
and
for
the
refurbished
building
(Scenario
2),
respectively.
Building production represents the most significant step of the building life
cycle, as it induces the largest contribution in the energy and environmental
impacts. Figure
7
shows the contribution of each life cycle phase to the building
CED. Production and maintenance are the most weighing phases on the life cycle
primary energy demand in both scenarios. With regard to the Baseline scenario,
they accounts for 55 and 45 %, respectively. The production and maintenance
shares also prevail over the other phases with respect to the environmental impact
indicators. In particular, production contribution varies from 43 % for EP to 64 %
for EP. Its contribution on GWP is nearly 63 %. Maintenance contribution varies
from 31 % for EP to 57 % for ODP. Its contribution on GWP is around 43 %.
Moving from the Baseline scenario to the Refurbishment scenario, production
and maintenance have a slight increase (1 % and about 4 %, respectively), while
end-of-life involves a reduction of 15 %, owing to larger rates of recyclable
materials in the Refurbishment scenario.
Conversely, the building operation presents the lowest energy and environ-
mental impacts in comparison with the other life cycle phases in both scenarios. In
the Scenario 1, it accounts for about 8.5 % on the CED.
With regard to the Refurbishment scenario, owing to the surplus of electricity
generated by the PV system, the operation phase involves significant negative
Table 5
Life cycle impact assessment results in both scenarios
Indicators
Metric
Baseline scenario
Refurbishment scenario
GWP
kg CO
2
eq
925,058
194,571
OPD
kg CFC-11 eq
0.09
0.004
POCP
kg C
2
H
4
eq
864.3
487.5
AP
kg SO
2
eq
2,841
-344.2
kg PO
4
3-
eq
NP
1,751
912
CED
MJeq
18,292,625
5,973,867
