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Hong Kong buildings account for 90% of total electricity consumption and over 60% of greenhouse gas emissions. Therefore buildings present both a challenge and an opportunity for reduction in energy use and greenhouse gas emissions. Net Zero Energy Building (NZEB) and Net Zero Carbon Building (NZCB) are recognised as feasible strategies to reduce energy use and carbon emissions leading to a more sustainable built environment. While there is a growing number of NZEBs and NZCBs in relatively cool or temperate climates, there are relatively few examples in the subtropical climate, and in a densely populated city such as Hong Kong. This paper will examine the current progress towards a low carbon built environment in Hong Kong, zero energy/carbon design strategies and technologies applicable to building in a subtropical climate, and examines a case study of Hong Kong's first zero carbon building ZCB. ZCB's energy and carbon performance, experiences and lessons learned, and future directions are discussed. The paper will conclude with the challenges and opportunities for wider adoption of NZEBs and NZCBs in the Hong Kong construction industry. [ABSTRACT FROM AUTHOR]

Abstract China has about 60 billion m2 of existing buildings, with approximately 2 billion m2 newly constructed each year. This accounts for half of all new buildings globally. A large number of buildings were demolished during the urban renewal process in China, significantly reducing the average lifespan of buildings and wasting vast amounts of energy and resources. However, the corresponding environmental impacts of reduced building lifespans have not been studied. Moreover, how to accurately evaluate future environmental impacts of construction projects is still a difficult problem, since in some cases the environmental impacts may not be realized for many years. In order to investigate the relationship between building lifespans and the corresponding environmental impacts, this paper first estimated the average lifespan of buildings in China through literature review, field investigation and calculation (using survival rate and demolition rate, respectively), revealing that the average building lifespan in China is from 25 to 35 years which is far shorter than the designed lifespans of buildings in China. It is also much shorter compared to the building lifespans in ten developed countries. Six buildings in Hebei Province in China were selected as case studies to conduct life cycle environmental (LCE) impact assessment. The results of the case studies indicate that (1) extending the building's lifespan from 30 to 50 years would reduce 40% of its total LCE impacts; (2) the environmental impacts caused by buildings (per area per year) in China is 2.3 times than that in the UK; (3) when environmental impacts are considered over time, they would decrease dramatically with the increase of discount rate, indicating that the buildings in developed cities in China with higher discount rates are more sensitive to environmental degradation. Highlights • The average lifespan of buildings caused by over demolition in China was estimated. • The building environmental impacts in different countries were examined. • Both life cycle embodied and operational environmental impacts were considered. • Time value of environmental impacts was also considered. [ABSTRACT FROM AUTHOR]

This paper selected typical flat and tower residential buildings in Beijing, China, to assess comfortable outdoor wind environments in summertime. Numerical analysis was carried out to evaluate design parameters that could influence the outdoor pedestrian-level wind environment during the summer. A total of twenty-seven valid cases using an orthogonal array, L 27 (3 13 ) orthogonal experimental design (OED) were selected. OED analysis showed significant probability and, therefore, the design parameters’ effects on the outdoor wind environment were quantitatively characterized at the pedestrian level. The conclusions were as follows: 1) design factors affecting the outdoor wind environment were found to be floor area ratio, façade direction, and greening rate; 2) the significance probability of design factors ranked highest to lowest in the order of greening rate > floor area ratio > façade direction > building arrangement. The results of such an evaluation can be used as an index for the planning and design process and for feedback of green building projects. [ABSTRACT FROM AUTHOR]

The development of green building in China has reached a new stage, needs to turn to the total energy consumption control from the technology control [1] . We should avoid packing technologies in green building projects and regard achieving good environmental performance as the fundamental goal. In this paper, we use the method of post-occupancy evaluation and regard the building environmental performance as the core of the evaluation system, in order to reduce the influence on the accuracy of results from the measures evaluation. We establish the evaluation index system of green public building environmental performance in severe cold and cold regions, including the index of building life-cycle carbon emissions accounting. And we set up the application plan of index and the scoring method, then we put forward a kind of evaluation grade based on environmental performance level, finally proposed the POE System of Green Public Building Environmental Performance in Severe Cold and Cold Regions (POE-GPBEPC). [ABSTRACT FROM AUTHOR]

Green real estate development is one of measures being implemented to reduce negative impacts of the building industry on the environment, society, and economy. However, there is lack of a systematic review of this large number of studies that is critical for the future endeavor. This paper reviews the existing body of knowledge related to green development. At first, the common research themes on green real estate development were identified, including concept, measure, business, and result. Then, the connotation and denotation of green real estate development was introduced in four dimensions. Third, the stakeholders of green real estate development and its benefits and costs were expatiated. Then, how to realize the green real estate development and its current weakness were analyzed in various aspects. It is found that the existing studies mainly focus on the environmental aspect of green building, other dimensions of sustainability of green building, especially the social sustainability is largely overlooked. Future research opportunities were identified such as the innovation of evaluation systems, integration of planning and design frameworks, management mechanisms and financing modes, and future proofing. [ABSTRACT FROM AUTHOR]

This study compared and analyzed both the energy savings and cost-effectiveness of various energy-saving technologies retrofitted to common buildings in China. Base models for an office and store building, set in representative climate zones of China-Beijing, Shanghai, and Guangzhou-were established and calibrated in EnergyPlus, a building energy simulation software program. Various energy-saving technologies were then applied to these models in EnergyPlus to calculate the overall energy savings under different climate conditions. In addition, a payback analysis was performed to determine the cost-effectiveness of each technology. The final results of this study can serve as a preliminary reference for selecting effective and economical energy-saving technologies to retrofit existing public buildings. [ABSTRACT FROM AUTHOR]