Titolo della tesi: The Impact of Urban Blocks Morphology on Urban Microclimate: The case of Tirana North Boulevard
Climate-responsive passive design is becoming an increasingly integral part of the urban environment in the light of climate adaptation challenges in cities. Patterns of urban blocks need to be explored to further understand the impact on urban microclimate. The design of urban morphology requires to positively adjust themselves to local climates conducted with knowledge-based investigation. Analyzing the contemporary urban blocks settlements and typological characteristics of the built environment is crucial to explore the relationship identified between urban morphology and density, building typology, and climate. Specifically, how can we i) Densify and design urban block fabrics to potentially improve the microclimate and the outdoor thermal comfort ii) Develop strategies to define the impact of the morphology and density of the building blocks on the urban climate iii) Investigate the concept of “density” in the topic of urban planning and positively apply it in the urban planning design as it has always been throughout the history of city structures iv) Integrate "new" bodies of knowledge, such as climatology, urban physics, meteorology, or computer science. This integration is necessary to the understanding of the energy phenomena that take place in the urban environment, whose large-scale impacts are still quite unknown and difficult to detect.
On the other side, modeling urban microclimate can assist urban planning decisions. Nonetheless, there is a lack of studies investigating the combined impact of urban block typology and urban indices on urban microclimate. Therefore, the present thesis analyzes the impact of these combined strategies on outdoor thermal comfort. The objectives of the study are: i) How dissimilar are the outdoor thermal conditions within the courtyards of varying enclosure forms, orientations, Height to X/Y courtyard dimensions and other morphological indices; ii) What drives the inner courtyard thermal diversity; iii) Are there optimal spatial strategies for retaining a non-extreme and diverse courtyard microclimate in the context of the Mediterranean climate.
In this context, by using computational fluid dynamics techniques, three zones with different courtyard block prototypes (in a range of large/small, deep/shallow, regular/distorted) of a winning Project - Grimshaw – New Tirana Boulevard - including combinations of urban indices (façade to Site Ratio, Building height to X/Y courtyard dimensions). To assess urban outdoor comfort at pedestrian height we used UTCI: Universal Thermal Climate Index. The results showed that block typology and urban indices affect urban microclimate. In addition, to explore the impact of urban indices within the same zone, a total of 5 different scenarios (namely SC 01-SC05) for each urban zone configuration with different block typologies, were used for the numerical simulations. The results showed that the performance of a block typology depends on the urban index values. For instance, increasing façade to site ratio, improves the UTCI values in all three zones typologies. The novelties of this study lie in the numeric microclimate modelling and longitudinal validations with these real courtyard geometries and exploring scenarios for analyzing the Universal Thermal Climate Index (UTCI) maps and identify the dissimilarities in the UTCI maps of courtyards within the context of New Tirana Boulevard.
On the other side, due to this complexity, it is not possible to draw easy-to-apply and universally valid climate guidelines, because every city is different, and so are the districts, streets, and buildings across a city. For this reason, it is crucial to understand the net impact of architectural and planning choices on the environmental performance of cities, including urban microclimate. Architects, planners, and engineers need to expand their understanding of the microclimate impact of design choices and the impact of urban context on the building performance. However, the full significance of the correlation between urban metrics and performance cannot be assigned to one single metric, as the complex interaction of climate- form- energy occurring in the urban environment cannot be represented by one single variable. Additionally, due to the complexity of the planning and design processes and work with architects and planners is expected to develop more design-oriented tools.