Civil Engineering Reference
In-Depth Information
Q
int
Sum of internal heat gains [MJ]
Q
sol
Sum of solar heat gains over the given period [MJ]
Q
tr
Total heat transfer by transmission [MJ]
Q
ve
Total heat transfer by ventilation [MJ]
Thermal transmittance [W/(m
2
U
K)]
Thermal transmittance of the ground floor [W/(m
2
U
g_floor
K)]
Thermal transmittance of the upper floor [W/(m
2
U
u_floor
K)]
Thermal transmittance of wall [W/(m
2
U
wall
K)]
Thermal transmittance of window [W/(m
2
U
window
K)]
/
int
Heat gains from internal heat sources [W]
g
e
Emission subsystem efficiency [-]
g
H,gn
Gain utilization factor [-]
g
ck
Heating system global efficiency [-].
1 Introduction: EPBD in Europe—State of the Art
and National Implementation (The Case of Italy)
Despite the prompt implementation commitment, the member states adopted the
Directive 2002/91/EC at various times; therefore, even if there was a common
frame, the development at national level is quite fragmented. In fact, the member
states decided their own strategy since a series of details, such as minimum
requirements for the energy regulation and schemes for calculation methods, were
not completely expounded in EPBD (Garcia Casals,
2006
). For example, the
French transposition of EPBD provides for compulsory requirements for new
buildings which are the overall energy demand and, in case of renovation, mini-
mum performance for construction elements, according to the surface, while
Germany established some mandatory energetic upgrades for existing buildings to
reduce the energy demand. Furthermore, strict minimum requirements were
established in case of refurbishment, both on the building components and on the
energy class: the target is usually class C, the minimum requirement for major
renovation is class B in Austria and Greece, which in case of new buildings
defined a detailed series of design requirements (Featuring Country Reports
2010
).
The common aim for the member states is to estimate the potential energy saving
and to find out suitable strategies for the refurbishment of national residential
building stock according to the construction typology (Balaras et al.
2007
;Poel
et al.
2007
).
In Italy, European Directive EPBD 2002/91/EC has been implemented with
delay, because Decree n. 192/2005 and n. 311/2006 did not indicate an assessment
procedure to evaluate the energy performance. Only on 2009, the Decree n. 59
indicated Technical Specification UNI/TS 11300 Part 1 and 2 as the reference for
