Pathways to net-zero carbon residential buildings : integrating low-carbon materials, passive and active design

This thesis investigates the optimization of whole-building life cycle greenhouse gas (GHG) emissions through low-carbon material substitution, passive design strategies, mechanical system upgrades, and renewable energy integration. A comprehensive framework integrating embodied carbon (EC) and operational carbon (OC) assessment within Life Cycle Assessment (LCA) is developed to quantify total emissions and support low-carbon design decision-making. Building Information Modeling (BIM) using Revit is applied to extract material quantities for EC calculation. A total of 36 low-carbon material substitution scenarios are developed using a locally sourced material inventory. Operational performance is evaluated using Building Energy Modeling (BEM) in EnergyPlus. Based on this, passive design strategies, including building orientation, airtightness, and window thermal performance, are optimized according to local codes. Active design strategies, including HVAC system upgrades and photovoltaic (PV) integration, are further incorporated to achieve deep decarbonization. A typical single-family house in Vancouver, British Columbia (BC), is used as the case study. The optimized pathway is further evaluated under future climate scenarios (mid-century and late-century) and extended to four additional BC climate zones to assess regional applicability. Results show that low-carbon material substitution reduces EC by up to 38.7%, while also contributing to a 10.6% reduction in OC. Passive design strategies further reduce OC by up to 62.0%. Replacing a natural gas furnace with an air-source heat pump combined with heat recovery ventilation achieves up to 93.6% OC reduction in Vancouver. The integration of PV systems enables net-zero operational carbon, while increasing the relative contribution of EC to total life-cycle emissions. The results further confirm the robustness of the optimized pathway under future climate conditions and across multiple BC climate zones.