Improving the microclimate in urban areas: a case study in the centre of Athens

The urban heat island effect and its consequences is one of the most important problems cities worldwide have to face in an effort to become more sustainable. This paper presents a study of a major open area in a densely built and populated area in the centre of Athens that was part of a Municipality of Athens program to improve thermal comfort conditions in open spaces. The bioclimatic rehabilitation design process was based on a specific strategy involving detailed monitoring of the thermal characteristics and climatic conditions in the area, extensive analysis of the results in order to define the problem, design and use of efficient passive cooling techniques (cool materials, green spaces, solar control and earth to air heat exchangers), and the use of advanced simulation tools to evaluate and optimise the planed microclimatic improvements. The results indicate that the proposed measures contribute to a decrease in local temperatures of up to 2 degrees C for summer conditions. Practical application: The knowledge on perceptions of microclimate in outdoor space can serve as a basis for urban spatial design. To evaluate the application of cool materials in public urban squares. Strategies to improve local microclimate with monitoring and modelling the design features.