Civil Engineering Reference
In-Depth Information
Fig. 8
Contribution of each retrofit actions to the GER in Stuttgart case study
With regard to the lighting, the efficient system and the improvement of the
daylight transfer together brought an electricity saving of 100 GJ/y and a related
saving of primary energy of 349 GJ/y (163.6 MJ/(m
2
y)).
3.2.6 Case study: Vilnius
The retrofit of the VGTU main building (Vilnius) included the following actions:
• replacement of the existing thermal insulation of the external walls and instal-
lation of high thermal performance materials,
• replacement of the existing windows with high-efficiency ones (low-e glasses
and low U-value),
• refurbishment of the roof with the introduction of a waterproof layer.
The assessed final energy saving was 794 GJ/y from the high-efficient win-
dows, and 852 GJ/y due to insulation and renovation of roofs and facades. The
related primary energy saving due to the high-efficient windows was 116 MJ/
(m
2
y), while the insulation of the building envelope provided a primary energy
saving of 125 MJ/(m
2
y). The total floor area of the studied building is 8,484 m
2
.
Figure
9
compares GER to total energy saving, and Fig.
10
shows the contri-
bution to GER of each retrofit action. The manufacturing of materials provided the
highest
impacts.
In
particular,
insulation
and
window
replacement
are
each
responsible for about half of the GER.
The construction phase represents about 5 % of GER, while the contribution
from wastes disposal is almost negligible. The construction phase required the use
of electricity and diesel oil to operate the building machineries.
The disposal scenario included the transportation of wastes coming from the
building site and their disposal to local landfills. GJ/y (919 MJ/(m
2
y)).
