Rising global temperatures, combined with increasingly dense urban environments, raise concerns regarding outdoor thermal comfort and indoor liveability. As cities become warmer, both energy demand and health risks increase, urging the need for effective climate adaptation strat
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Rising global temperatures, combined with increasingly dense urban environments, raise concerns regarding outdoor thermal comfort and indoor liveability. As cities become warmer, both energy demand and health risks increase, urging the need for effective climate adaptation strategies. This thesis investigates how different green interventions affect outdoor and indoor temperatures in the Netherlands, and how these measures influence building cooling loads during heatwaves. Green interventions used in this study are trees, green roofs, green walls, shrubs, and grass. Within 10 m of the buildings, green is implemented to represent realistic opportunities for greening in private gardens and immediate surroundings. As a result, the simulated cooling effects reflect local-scale interventions rather than district-wide greening strategies. The Dutch heatwave from 23–27 August 2019 served as a reference event to assess three representative Dutch building typologies: low-rise, mid-rise, and high-rise.
A one-way coupled approach between an urban climate model (UCM) and a building energy model (BEM) is applied. For both the UCM and BEM, different model options were considered and compared. The selected models were then further evaluated against findings from literature to assess their suitability and accuracy. The outdoor microclimate was simulated with the ENVI-met model, which provides detailed outputs of air temperature, wind speed, and Physiological Equivalent Temperature (PET) at pedestrian height (1.5 m). Indoor thermal conditions and cooling energy demand were then evaluated using the building energy model IES-VE, with the microclimatic outputs from ENVI-met serving as boundary conditions. This coupling provides a more realistic estimation of the benefits of green infrastructure compared to building energy modelling that relies on standardised weather data.
The results show that the coupled ENVI-met–IES-VE framework successfully reproduced outdoor and indoor temperature reductions within the range reported in the literature, though typically at the lower end. This is expected, as the relatively small amount of greenery applied was intentionally chosen to isolate and quantify the local effect of greening around buildings. Among all interventions, trees produced the strongest cooling effect due to their shading capacity and evapotranspiration, with the largest impact observed when trees were combined with other types of greenery. Across all typologies, reductions of up to 1.17 °C in average outdoor air temperature, 3.92 °C in local maximum air temperature, and 13.45 °C in maximum PET were observed. Indoors, green interventions reduced peak air temperatures by up to 1.20 °C and cooling loads by as much as 32%. The relative effectiveness differed across building typologies: low-rise dwellings benefited most due to their closer interaction with the modified microclimate, whereas high-rise buildings showed more limited improvements.
This thesis provides a coupled UCM–BEM framework applicable to multiple Dutch building typologies, offering new insights into the role of vegetation in a temperate maritime climate. The modelling approach can be used to test different greening scenarios across building typologies. Future research should validate this framework with on-site measurements to further improve accuracy. Furthermore, combinations with shading devices and adaptive occupant behaviour should be explored in future research. The insights gained can guide municipalities, urban planners, and property owners in designing greener, more comfortable, and energy-efficient urban environments.