Over 70% of a pupil’s school life is spent inside a classroom, and indoor air quality has a significant impact on students’ attendance and learning potential. Therefore, the indoor air quality in primary school buildings is highly important. This empirical study investigates the indoor air quality in four naturally ventilated schools in China, with a focus on four parameters: PM_2.5, PM₁₀, CO₂, and temperature. The correlations between the indoor air quality and the ambient air pollution, building defects, and occupants’ activities have been identified and discussed. The results indicate that building defects and occupants’ activities have a significant impact on indoor air quality. Buildings with better air tightness have a relatively smaller ratio of indoor particulate matter (PM) concentrations to outdoor PM concentrations when unoccupied. During occupied periods, the indoor/outdoor (I/O) ratio could be larger than 1 due to internal students’ activities. The indoor air temperature in winter is mainly determined by occupants’ activities and the adiabatic ability of a building’s fabrics. CO₂ can easily exceed 1000 ppm on average due to the closing of windows and doors to keep the inside air warmer in winter. It is concluded that improving air tightness might be a way of reducing outdoor air pollutants’ penetration in naturally ventilated school buildings. Mechanical ventilation with air purification could be also an option on severely polluted days.

This paper is based on an ongoing research project funded by the World Bank GEF Program, which aims to identify the key barriers to green building development in Ningbo China and suggest policy improvements to the local government. China is undergoing the largest scale of urbanization in history and at an unprecedented pace. The construction and operation of buildings have inevitably brought severe pressures on resource conservation and environmental protection. China has initiated policies, strategies and financial incentive schemes at national level to address these issues. It is also seen that there is a growing interest in recent years at local government level in promoting green buildings. This paper will take a look at the current national policies and targets and then discuss the motivations and opportunities of developing green buildings from a perspective of local governments. Questionnaire surveys and interviews with relevant stakeholders have been conducted in the case study city. Based on the surveys and interviews, the key barriers to developing green buildings in the case study city have been identified, and recommendations for policy change are proposed.

From the 1970s to the 1990s, over 3.5 billion square meters of residential building areas were completed in China to accommodate the increased population in cities. Most of the constructed buildings were built without insulation and proper ventilation. Currently, these buildings are reaching the end of their designed service lifetime. Therefore, retrofitting and rebuilding represent two different options to upgrade or completely replace these old buildings. However, material utilization levels of retrofitting and the rebuilding plans are completely different, resulting in different embodied energy consumption and operation energy consumption levels. This study examines the old residential buildings located in the cold climate zone of China. The study found that rebuilding these old residential buildings normally attain higher embodied energy consumption and embodied CO₂ emissions due to high material input. Therefore, rebuilding plans might not be the highest priority, and government managers should consider the environmental impacts from the embodied energy consumption when formulating decisions regarding the future of these old residential buildings. Additionally, the insulation thickness is an important parameter for the main building fabrics of retrofitted and rebuilt buildings to reduce heating and cooling energy demand. Although, this study has identified that the rebuilt buildings cause higher CO₂ emissions than retrofitted buildings. However, various parameters, such as the materials’ embodied coefficient, the carbon intensity of the operation energy sources and ratios of the surface areas of the glazing windows to the external walls, should be considered by decision-makers.