Abstract/Summary

Rapid urbanization and a warming climate present challenge for managing energy demand and mitigating heat in urban environments. Buildings, as dominant elements of urban landscapes, play a crucial role in influencing the urban energy balance through anthropogenic heat flux (QF,B) and heat storage flux (ΔQS), thereby altering the urban thermal environment (e.g. near surface air temperature, wind speed). These modifications, in turn, impact building thermal performance and energy use, creating a feedback loop between buildings and the urban climate. Understanding these complex interactions and the role of building characteristics is crucial for developing appropriate building designs not only improve building energy efficiency but also contribute to urban climate modulation. This thesis uses building energy modelling EnergyPlus and urban land surface model SUEWS to quantify how building designs influence this interaction. An analytical expression of QF,B is proposed to address its time lag and magnitude difference compared to the commonly used proxy (building energy consumption QEC). The temporal differences at the diurnal scale are attributed to changes in storage heat flux induced by human behaviours (ΔSo-uo), which primarily are influenced by building operations related to thermal comfort, such as mechanical cooling and natural ventilation. The new method for estimating QF,B is applied to further simulation work, which reveals U-value, thermal mass levels and occupancy patterns are the most important factors to shape the diurnal patterns of QF,B, which should be considered in urban climate modelling. The Objective Hysteresis Model (OHM) is improved by developing a dynamic parameterization scheme for its empirical coefficients, derived from building energy modelling data. This parameterization allows the OHM coefficients to respond to variations in building construction properties and meteorological conditions, thereby reducing biases of ΔQS compared to using fixed coefficients derived from long-term observations. Furthermore, a two-way coupling between the SUEWS and EnergyPlus is introduced, capturing feedback mechanisms between retrofitted buildings and neighbourhood climate across different U.S. climate zones. The results show a pronounced winter nighttime overcooling effect and secondary feedback on heating energy demand due to reduced outdoor temperature. This impact of energy retrofitting is more pronounced in low-wind cities, where high aerodynamic resistance amplifies the temperature feedback resulting from changes in QF,B. Overall, this thesis extends the current understanding of how building factors influence the interaction between building and urban environment through QF,B and ΔQS. The methods and insights developed here can guide policymakers and building/urban planners in formulating strategies for sustainable urban development and enhancing climate resilience.