Green Roof Energy Performance across Cfb/Oceanic Climates: Simulating Climate Change and Future Trends

Green roofs represent a hallmark of sustainable design and provide opportunities for increased recognition and credits within sustainability assessment frameworks. This study examines the thermal performance of green roofs in Auckland, Christchurch, and Wellington, considering two scenarios: present conditions as a “baseline scenario” and future climate change projections for “scenario 2050.” Firstly, we simulated green roofs to measure the Total Fuel Consumption (TFC) of a single residential building for heating and cooling purposes with a green roof compared to the same building with a traditional bare roof using Design Builder software. Then, we utilized the Climate Change World Weather File Generator tool to predict future climate change trends in 2050. The findings reveal substantial energy-saving potential in oceanic climates. In the baseline scenario, the green roof could reduce TFC by about 3% (Auckland), 2% (Christchurch), and 1% (Wellington). In scenario 2050, these reductions increase to 3.3%, 2.6%, and 1%, respectively. Notably, green roofs exhibit an impact during summertime, with TFC reductions of approximately 8.5% (2022) and 9% (2050) in Auckland, 4.5% (2022) and 5.6% (2050) in Christchurch, and 1.5% (2022) and 0.2% (2050) in Wellington. Thus, the findings of this research not only contribute to a deeper understanding of promising techniques to combat climate change but also provide valuable insights that can inform decision-making processes regarding sustainable urban development towards Sustainable Development Goal 13.