Comparative life cycle assessment of various energy efficiency designs of a container-based housing unit in China: A case study

Providing sustainable and affordable housing in rapidly developing regions in East Asia is an essential need, which can be satisfied by the market implementation of prefabricated, modular units, with a high energy-efficient performance. This study presents a comparative analysis of a factory-made residential unit, produced and located in Shanghai, China. A combination of energy analyses and life-cycle assessments is performed to quantify the life-cycle impacts related to various energy efficiency designs (convectional, low-energy, net-zero energy and off-grid) of a building module, developed from a new shipping container. The life-cycle assessment results indicate that the net-zero energy design strategy has the lowest life-cycle impacts in all categories, with 26% reduction in water consumption and up to 86% reduction in terms of global warming potential with respect to the convectional, baseline design. The ambition of becoming independent from the local electricity grid in the off-grid design results in nearly two-fold larger PV system when compared to the net-zero energy design, resulting in average 59% increase of total life cycle impacts. The sensitivity analysis shows that projected climate change effects have a minor influence on the life-cycle impacts, whereas the potential reuse of the building structure provides significant environmental benefits. Comparison with existing literature studies demonstrates the significant GHG emissions mitigation potential related to the implementation of off-grid and zero energy buildings in rural, remote, or post-disaster areas with limited electricity access and energy facilities based on fossil fuels.