Decarbonizing High-Rise Buildings in Cold Climates: Net-Zero Energy Strategies and the Role of Solar Energy

Despite growing emphasis on Net-Zero Energy Buildings (NZEBs), several gaps hinder their effective implementation. Ambiguity in NZEB definitions creates inconsistencies in reducing greenhouse gas emissions and limits practical applications. This thesis evaluates the influence of NZEB definition on GHG emissions, the feasibility of high-rise applications, and the influence of building height on the solar energy and desiccant cooling systems energy contribution.Chapter 2 evaluates the GHG reduction effectiveness of four widely accepted NZEB definitions in Toronto and Miami. The findings reveal that complying with the net-zero energy cost definition is most effective, reducing emissions by up to 145% in Toronto and 117% in Miami. Conversely, complying with the net-zero emission definition is the least effective, permitting significant residual emissions. Chapter 3 investigates the feasibility of achieving NZEB status in high-rise buildings. Findings show that achieving NZEB status in 40-storey buildings is only feasible at low Energy Use Intensities (EUIs) (17–28 kWh/m²a). However, the best-performing residential and commercial buildings typically have EUIs of 50–75 kWh/m²a. Achieving such EUIs in high-rise buildings is only feasible if building heights are restricted to 5–10 floors. Chapter 4 assesses the influence of building height on the potential contribution of solar energy and solar desiccant cooling systems to the energy needs of commercial buildings in cold climates by examining three configurations of Photovoltaic (PV), Photovoltaic-Thermal (PVT), and five building heights. The findings show that while low-rise buildings can achieve near self-sufficiency, the overall relative contribution of these technologies declines sharply in mid-rise buildings and becomes negligible in high-rise configurations. Shading from adjacent buildings has an opposing effect on solar-driven desiccant cooling systems: it can improve cooling coverage when roof solar availability is maintained but consistently reduces the heating contribution from solar thermal. The impact depends strongly on roof exposure. Equal-height surroundings leave roof collectors unshaded. Taller adjacent buildings, however, impose significant roof shading, sharply decreasing heating coverage and moderately reducing cooling contributions. Together, these findings provide a comprehensive analysis of the challenges and opportunities in transitioning to NZEBs, offering actionable insights for advancing decarbonization and sustainable urban development.

Department dc:contributor.department

Geography

Year dc:date.issued

2026

Author dc:creator

• Shirinbakhsh Masouleh, Mehrdad

Advisor dc:contributor.advisor

• Harvey, Danny

Handle dc:identifier.uri

https://hdl.handle.net/1807/153730

OAI record oai:identifier

https://utoronto.scholaris.ca/server/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Autoronto.scholaris.ca%3A1807%2F153730