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Research on the experiences of the recent tremendous rural construction and restructuring in China show that the social dimension of sustainability is crucial for the success of rural development. However, most conventional built environmental sustainability assessment tools (BESATs) are mainly focussed on environmental sustainability and building performance. There are to date no useful or complete assessment methods of social sustainability in the rural built environment. This study reviews the concept of the social dimension of sustainability and its application in architecture. Several existing BESATs are analysed and compared to identify their features and gaps in the assessment of social sustainability. From this, a series of indicators of social sustainability in the built environment are developed and discussed in the context of the current situation and challenges in poor rural areas in China. Compared with conventional BESATs, the social dimension of sustainability assessment method (SDM...

The exchange of radiant fluxes between different surfaces in an outdoor environment can be described with an enclosure theory. It provides a physical understanding of the relationship between different surfaces and consequent radiant fluxes within an enclosure, which is constructed by including surfaces of building facades and an imaginary surface of sky dome. Radiant fluxes on a surface can be expressed as linear combinations of view factors. This study examines the linear dependencies of urban radiant fluxes on view factors, namely Sunlit View Factor (SLVF), Green View Factor (GNVF), and Sky View Factor (SVF), using an empirical regression analysis. Results revealed a simple and linear correlation between view factors and outdoor radiant fluxes. As such, a quick estimation of the potential increase in the outdoor mean radiant temperature in relation to neighboring built environments can be achieved, and industry guidelines for designing thermally comfortable open spaces can be formulated accordi...

Understanding the urban microclimatic spatial distribution and its impact on thermal comfort is important for integrating climatic consideration into urban design process. This article presents a case study in Tsim Sha Tsui and Tai Po of Hong Kong densely built-up areas to investigate the spatial distribution of microclimatic condition. Air temperature (Ta), wind speed (v), relative humidity (RH) and globe temperature (Tg) of 87 locations in two selected sites were measured on a summer day and a winter day respectively. Physiological Equivalent Temperature was calculated to analyse the thermal comfort condition in two sites. Both numerical simulation and geographical mapping approach were used for the estimation of the microclimatic spatial distribution. Results show that the influence of urban morphology on the microclimatic spatial distribution can be well investigated by using numerical simulation while geographical mapping based on measured data shows higher estimation accuracy due to the consideratio...

Understanding how greenery can improve outdoor thermal comfort is important in downtown planning. This article presents a simulation approach to investigate the cooling effect of downtown greenery on the urban microclimate, primarily air temperature and solar radiation, and therefore pedestrian thermal comfort during summertime in Hong Kong. The numerical simulation software of ENVI-met was used to generate microclimate data for a downtown development site with and without greening design scenarios. Two types of scenarios were tested, one being 50% of tree coverage and the other being 30% of grass coverage with modified building design. The simulation results were transformed into geographic information system (GIS)-supported format using self-developed computer programs. Another computer module was developed to assess pedestrian thermal comfort based on the human–biometeorological index of physiological equivalent temperature (PET) within a GIS framework. Thermal comfort maps were generated accordingly. ...

Designing natural ventilation systems for quality urban living in high-density cities such as Hong Kong is never an easy task. Since 1903, Hong Kong has been tackling this issue. The intensification of urbanization in the last 100 years has meant that urban ventilation is compromised. For sub-tropical living, especially in the summer months, air flow in interior spaces can greatly assist thermal comfort. To come up with an ideal design, both the outdoor and the indoor wind environment must be optimized. Since 2003, the Hong Kong SAR Government has commissioned various studies and has begun to implement policies to address the issue. These studies are ongoing as of today. However, continuous research and monitoring are still needed.

The thermal conditions encountered in outdoor urban spaces are a major determinant of the patterns of usage of the spaces. For better urban planning and design, the issue of outdoor comfort should be highlighted. This paper summarizes an extensive literature review on outdoor comfort studies. It seeks to understand the effects of airflow on pedestrian comfort in three categories: wind force, wind chill, and thermal comfort. The paper then develops guidelines for urban Hong Kong based on the findings. A comfort outdoor temperature chart for Hong Kong was developed based on the results. Urban wind speeds ranging from 1.0 to 2.0 m/s are recommended for pedestrian comfort in shade on typical clear sunny days in summer Hong Kong.

The subtropical climate of Hong Kong has resulted in a significant amount of energy use for comfort cooling in summer.The situation is getting even worse because of the widespread use of household air-conditioners in high-rise residential buildings in the last two decades. To improve the situation, it is believed that thermal comfort has to be made an important agenda in building design. This paper discusses the adaptive model in thermal comfort, which has been included in the new revision of ASHRAE Standard 55-2004. Furthermore, it demonstrates the development of a comfort temperature chart for naturally ventilated buildings in Hong Kong. Based on the findings of this study, indoor natural ventilation to airspeed of about 1.0—1.5 m/s would likely satisfy the thermal comfort requirements of 80% of occupants during the hot summer period in Hong Kong.