Microclimate response of urban fabrics




 The objective of this project was to better understand the ways in which small-scale structures of the urban fabric contribute differentially to heat island effects. This information was used to develop specific strategies for counteracting and mitigating these effects on a local basis.


Project description

 The aim of this project was to identify climate-sensitive urban patterns and to suggest concrete open-space design measures to counteract the overheating effect during hot summer days. First, an urban fabric typology was generated to identify type characteristics of open-space structures and microclimate conditions. Urban fabric types were defined by terrain, urban morphology, and open-space characteristics.

In parallel, a field study at a reference location aided the exploration of microclimatic conditions in different situations, and results from the Envimet 4.0 microclimate simulation model were calculated and assessed in comparison with the observed measurements. Based on the evaluation of the simulation results, a catalogue of open-space design measures was compiled. Also, representative packages of measures were defined for each sample quadrant, highlighting specific conditions based on open-space patterns and climate sensitivity. The forward focus of these measures is to optimise thermal comfort amelioration efforts.


Main conclusions/outcomes/achievements

  • Climate change projections consistently point towards an increased occurrence and intensity of heat waves, which are expected to become a significant urban health problem.
  • Urban greening is a key to decreasing urban temperatures, avoiding higher irradiance, and supporting nocturnal cooling through energy flux to the open atmosphere — thereby improving outdoor and indoor thermal comfort levels.
  • The urban fabric typology developed in this project helps to apply appropriate amelioration measures to fit specific urban patterns. 
  • The project’s microclimatic simulations showed a high variation between different urban fabric types. It was demonstrated, for example, that the selection of optimal locations for single planting measures can be more important than a general expansion of green space.