Civil Engineering Reference
In-Depth Information
State of the Art on Retrofit Strategies
Selection Using Multi-objective
Optimization and Genetic Algorithms
Ehsan Asadi, M. Gameiro da Silva, C. Henggeler Antunes
and Luís Dias
Abstract The retrofit of a building involves not just the fulfillment of functional
requirements, but also considerations such as investment costs, energy consump-
tion, environmental impact, and occupant well-being. Careful long-term decisions
in the retrofit and operation of buildings can significantly improve their thermal
performance and thus reduce their consumption of energy. Moreover, they can
improve indoor environmental quality in buildings. Alternative building energy
conservation measures, standards compliance, and economic optimization can be
evaluated using available energy analysis and decision-aid techniques. These may
range from simplified energy analysis methods for approximate energy use esti-
mates to detailed computerized hourly simulation coupled with decision-aid
techniques. This chapter reviews the research and development in the decision
support processes in building retrofit. Special attention is devoted to the meth-
odologies using multi-objective optimization and genetic algorithms. Accordingly,
the decision methodologies are broadly separated into two main categories:
approaches in which alternatives are explicitly known a priori and approaches in
which alternatives are implicitly defined by an optimization model. The advan-
tages and drawbacks of the various methods in each category are also discussed.
1 Introduction
The building sector is the largest user of energy and CO
2
emitter in Europe and the
USA. Besides, it is responsible for about 40 % of the EU's and the USA's total
final energy consumption. Even if all future buildings were to be built so that their
energy demand was very low, this would still only mean that the increase in energy
