Civil Engineering Reference
In-Depth Information
These lines of research have allowed addressing many problems as far as
building retrofit is concerned. However, most of them consider that a list of
predefined and pre-evaluated alternative variants of the building retrofit options is
given. In case a small number of such solutions have been defined, there is no
guarantee that the solution finally reached is the best one (from the DM's per-
spective). On the opposite, when a large number of solutions are defined, the
required evaluation and selection process may become extremely difficult to
handle.
The problem faced by the DM may also be framed as a multi-objective opti-
mization model, in which multiple and competing objective functions are for-
mulated to assess feasible alternatives, which are not predefined but are implicitly
defined by a set of constraints.
Based on an extensive literature review and Fig.
1
, it could be stated that most
methodologies for decision support in energy management and sustainability in
building sector follow three major steps:
• Definition of main objectives/criteria of the project;
• Definition of alternative retrofit actions, either by stating them explicitly or
defining a comprehensive mathematical model; and
• Selection of assessment methodologies adequate to the model.
Accordingly, the remainder of this chapter overviews the main objectives in the
course of building retrofit. Different building retrofit technologies are reviewed in
Sect.
2.2
. Furthermore, retrofit action selection methodologies are discussed in
Sect.
2.3
. Finally, Sects.
2.4
and
3
in summarize conclusions and discuss issues for
future research and development.
2.1 Objectives in Building Retrofit
The objectives for building retrofit can be either quantitative or qualitative and can
be divided into four main categories depicted in Fig.
2
(Kolokotsa et al.
2009
).
More specifically, regarding energy use (primary
or final), the following
objectives have been utilized (Kolokotsa et al.
2009
):
• heating and cooling load for conditioned buildings (D'Cruz and Radford
1987
;
Bouchlaghem
2000
);
• normalized annual energy consumption and energy use for heating in kWh/m
2
;
• (Rey
2004
;Zhu
2006
);
• annual electricity use in kWh/m
2
(Rey
2004
);
• embodied energy (Chen et al.
2006
);
• energy and time consumption index (ETI) (Chen et al.
2006
); and
• energy savings due to building retrofit in kWh/year (Gholap and Khan
2007
;
Asadi et al.
2012a
).
