Net-Zero Courtyard: Passive Strategies for Urban Housing Blocks

Thesis Abstract

Urban housing blocks face rising energy costs, overheating risks, and inequitable access to daylight and outdoor spaces; passive design strategies offer a pathway to net-zero energy performance and improved dwelling quality without reliance on active systems. This study investigates the effectiveness of courtyard-centered passive strategies in delivering net-zero performance for dense urban housing blocks through design, implementation, and evaluation phases. The aim is to develop a replicable design framework that optimizes thermal comfort, daylight autonomy, natural ventilation, and solar-energy integration within shared courtyards while maintaining affordability and social sustainability. Specific objectives include (1) to identify courtyard typologies and passive design components that most strongly influence energy use intensity (EUI) and peak cooling loads; (2) to quantify the relationship between courtyard geometry, shading devices, thermal mass, vegetation, and natural ventilation using predictive performance models; (3) to implement a scale-model and a full-scale exemplary courtyard retrofit in a live urban precinct, and (4) to evaluate occupant comfort, behavioral responses, and perceived thermal quality through mixed-methods analysis. The methodology adopts a mixed-methods research design, combining conventional design computation with empirical field validation. The population comprises 12 urban housing blocks in a mid-latitude metropolis characterized by hot-dummer summers and moderate winters. A stratified sample of four blocks will be selected for in-situ instrumented monitoring and retrofit simulations, with two blocks serving as control and two as intervention cases. Data collection instruments include 60-channel thermal sensors for indoor and courtyard microclimate, meteorological stations, sub-metered electrical meters, photometric sensors for daylight autonomy (DA) assessment, and five portable data-loggers for occupant comfort surveys. An accompanying 1200 scale physical model will test variable courtyard geometries, shading configurations, and planting schemes, enabling calibration of computational analyses. Validity and reliability will be ensured via triangulation across monitoring data, a 6-month measurement campaign, and pre-/post-retrofit observations. Data analysis will employ a combination of regression analysis to quantify relations between courtyard parameters and EUI, ANOVA to compare performance across typologies and retrofit scenarios, and structural equation modeling (SEM) to explore causal pathways among passive design drivers, thermal comfort, and energy outcomes. A high-fidelity energy simulation model (EnergyPlus) will be calibrated against measured data, enabling scenario analysis of alternative envelope materials, massing, and shading strategies. The study will also apply a thematic analysis of occupant interviews to capture perceived comfort, usage patterns, and acceptance of courtyard-based passive strategies. Expected findings indicate that courtyard geometries featuring moderate width-to-length ratios, high-albedo surfaces, and strategically placed deciduous shading trees can reduce cooling loads by 18–32% and increase daylight autonomy by 15–25% in summer months, while daylight penetration remains adequate in winter due to seasonal solar angles. The coupling of high thermal-mass floors with breathable, ventilated courtyards is anticipated to improve indoor operative temperatures by 1–2°C during peak heat events. Regression and SEM results are expected to reveal statistically significant pathways from shading strategy and vegetation density to energy performance and occupant comfort, mediated by airflow patterns and solar heat gain. The study anticipates that occupants perceive improved thermal comfort and social vitality in courtyards designed with flexible shading devices and accessible microclimate controls, though maintenance considerations and initial retrofit costs will be highlighted as critical variables. Contributions to knowledge include a transferable design framework for net-zero courtyard design in dense urban housing blocks, an empirical dataset linking courtyard morphology to energy and comfort indicators, and a validated modeling workflow integrating physical testing with high-resolution simulations. The research will inform policy recommendations for courtyard-oriented passive design guidelines, retrofit standards, and cost-benefit analyses for urban housing stock. The main conclusion posits that well-optimized courtyard configurations, combined with native or climate-adapted vegetation and low-energy shading systems, can realize substantial energy savings while delivering enhanced daylight, ventilation, and social performance. Recommendations include prioritizing courtyard integration in neighborhood renewal programs, developing standardised performance metrics for courtyard-embedded passive strategies, and advancing modular retrofit kits to facilitate scalable implementation in mid-density housing contexts.