Introduction
Cities are home to more than half of the world population [1] and consume the majority of global energy [2] and
resources. Future cities will be faced with the necessity to reduce their energy demand significantly while shifting to
local urban energy production systems. Political instruments, such as the energy performance of buildings directive
(EPBD) [3], are already in place to prepare for net zero-energy buildings, and eventually, net zero-energy
communities and cities in the European Union. An increased use of active solar energy as well as an awareness of
the passive use of solar energy -by solar gains and daylight- is needed to reach sustainable solutions. Smart planning
of new urban districts will help cities to reach their goals of energy reduction and energy production; in such a way
that urban districts could become more self-reliant [4].
The urban design process is a complex one with a range of stakeholders taking various decisions at each stage of
the process. Solar energy is just one of the many parameters affecting this process [5], but paradoxically, the energy