This section discusses the various functions of skycourts in high-rise buildings from environmental, social and economic perspectives.
2.2.2.1 Overview of Skycourts from an Environmental Perspective
Skycourts provide different benefits from an environmental perspective, taking into consideration their impact on the urban setting, starting from the city scale narrowing down to the building scale. Thermal comfort, indoor air quality, biodiversity, and potential to be efficient spaces in buildings are the main matters.
The skycourt is an environmental filter or buffer: Skycourts could be defined as environmental filters (Table 2-1). They could play the role of thermal buffers to mediate the temperature between exterior and interior, allowing air to penetrate to the interior (Pomeroy 2014), and reducing the impact of solar radiation (Jahnkassim and Ip 2006). These features could provide positive impacts on the interior thermal conditions and occupants, as it offers a comfortable indoor environment in terms of air temperature, relative humidity and air velocity (Ismail et al. 2011). In addition, skycourts could allow daylight to penetrate into the interior environment (Pomeroy 2014), and act as acoustic buffers between spaces (Wong et al. 2010), which, therefore, improves occupants’ satisfaction. Transitional spaces such as skycourt gardens at balconies and roofs could
enhance thermal comfort performance and air temperature variations in high-rise buildings (Taib et al. 2014). Moreover, greenery could enhance air quality by filtering out pollutant organisms (Lovell and Johnston 2009; Khan et al. 2005). Sky-gardens at the top of buildings could reduce room temperatures beneath the structure by 10% (Wong et al. 2010), and have potential in reducing roof heat losses during cold days in winter in hot climates (Jaffal et al. 2012).
Table 2-1. Benefits of skycourts in different studies from environmental perspective – skycourts as buffer zone
The Skycourt as an Environmental Buffer Filter
(Pomeroy 2014) (Jahnkassim and Ip 2006)
(Ismail et al. 2011) (Taib et al. 2014) Skycourts can
allow light and air to penetrate into the interior
Skycourts may play a role as a ‘thermal buffer’ that reduces the impact of solar radiation and glare
Bioclimatic elements such as skycourts offer a more comfortable indoor environment, and increase satisfaction Skycourts as transitional spaces (skycourt garden, balcony garden and rooftop) can enhance thermal comfort (Lambeth Council
2010)
(Castleton et al. 2010) (Jaffal et al. 2012) Sky-roof offers
benefits to building and its surrounding environment
Sky-roof with greenery can reduce the summer indoor air temperature by 2°C, and the annual energy demand by 6%
Sky-roofs with gardens are thermally beneficial for hot, temperate, and cold European
climates.
In the summer, the roof passive cooling effect was three times more efficient with the green roof. In the winter, the green roof reduced roof heat losses during cold days; however, it increased these losses during sunny days. (Khan et al. 2005) (Lianga et al. 2014) (Giridharan et al. 2008)
Plants improve air quality, increase pleasantness, and help to improve performance
Vertical greenery can lower the
temperature of its surroundings
Increasing the tree cover from 25% to 40% in the pocket parks in coastal area could reduce daytime urban heat island intensity (UHI) by further 0.5-1°C.
Future research in high-rise environments should incorporate sky-roof and sky terrace gardens.
The skycourt as a ‘biodiversity enhancer’: Biodiversity represents the degree of variation in life systems within a specific ecosystem, as well as being a measure of the health of an ecosystem (Hui and Chan 2011). Scholars argued that planted skycourts, sky-terraces and sky-roofs could form examples of design elements in buildings, which could enrich the biodiversity and enhance urban ecosystems starting from the city scale down to the building scale (Pomeroy 2014), (Table 2-2). It was found that improvement of biodiversity
could have positive impacts on the quality of life of occupants and facilitate preservation of biodiversity in natural ecosystems (Savard et al. 2000). Hui and Chan (2011) claimed that the built environment created by green roofs is one of the methods for biodiversity conservation, as green roofs have the potential to function as islands of biodiversity within urban and suburban environments. Williams et al. (2014) found that spatial plans, heights, linkages and total areas of green roofs within a city are key elements contributing to biodiversity benefits. These should be considered in any policies advocating green roofs as habitats (Williams et al. 2014). Burghardt et al. (2009) stated that enhancing the biomass and the diversity of native plants would increase the diversity of insects, creating a resource base for important animals such as birds (Burghardt et al. 2009). However, the real impact of skycourts on biodiversity based on real-state high-rise buildings needs more investigation.
Table 2-2. Benefits of skycourts in different studies from environmental perspective – skycourts as biodiversity enhancer
Skycourt Greenery as a Biodiversity Enhancer
(Williams et
al. 2014)
(Burghardt et al. 2009)
(Hui and Chan 2011) (Savard et al. 2000) Sky-roofs’ gardens might help achieve urban biodiversity conservation goals Enhancing the biomass and diversity of native plants would increase the diversity and abundance of insect herbivores and thus create a greater resource base for important
insectivores such as birds
Sky-roofs’ gardens have the potential to function as islands of biodiversity within urban and suburban environments. Building development in the urban areas will destroy the habitats and result in
biodiversity loss
Improvement of biodiversity in urban systems can have a positive impact on the quality of life and education of dwellers and thus facilitate the preservation of biodiversity in natural ecosystems
The skycourt as a passive design enhancer: Passive design refers to a series of strategies integrated in the architectural design to develop a building that responds to climatic requirements such as sun and wind among other contextual needs (Cantón et al. 2014). Such designs could have potential to reduce energy consumption and to improve the quality of life. Skycourts could provide contemporary alternatives to the vernacular courtyard in high-rise buildings due to their potential to allow natural air to enter deeper into the interior of buildings. In addition, skycourts could be considered as passive cooling techniques due to their greenery effect that are thermally beneficial in different climatic regions, hot or cold, (Table 2-3).
Table 2-3. Benefits of skycourts in different studies from environmental perspective – skycourts as passive element
The Skycourt as a Passive Design Element
(Zhou et al. 2014) (Jaffal et al. 2012) (Ismail et al. 2011) (Castleton et al. 2010) Passive ventilation in
buildings has a great potential for conserving energy and improving the health of occupants
In summer, the passive cooling effect of a sky-roof with greenery was three times more efficient than a plain roof.
In winter, the green sky-roof reduced roof heat losses during cold days
A building which incorporates skycourts can offer a more comfortable indoor environment in terms of air temperature, relative humidity and air velocity in passive manners
Sky-gardens are passive cooling technique that stop incoming solar radiation from reaching the building structure below. This has potential in energy efficiency and offers benefits in winter heating reduction as well as summer cooling
Cooling utilisation in summer and heating use in winter were reduced with sky-gardens at the top of buildings, which in turn cause reductions in annual energy demands by 6% (Castleton et al. 2010). The passive cooling effect of sky-roofs with greenery was found to be three times more efficient than ordinary concrete roofs during the summer in hot climates (Jaffal et al. 2012). Moreover, these green roofs could reduce heat gain by about 60% compared to smoother surfaces due to reflection (Yeang 1999).
Furthermore, skycourt can provide environmentally indoor public space that has potential to be lit and introduce daylight into the adjacent spaces in buildings, significantly, when it acts such as transitional buffer areas. Previous studies have recognised the daylight potential of similar vertical spaces of skycourts such as atria (Chi et al. 2017; Li et al. 2014; Chows et al. 2013; Samant 2010; Sharples and Lash 2007). Generally, daylight levels within atrium spaces are sufficiently high. In addition, such spaces can reduce lighting energy demand of buildings. However, concerns regarding comfort levels of illumination and glare, in addition to overheating in adjoining spaces could be raised. Therefore, daylight- linked lighting controls can deliver excellent energy savings in such circulation spaces. For example, in a study investigated this issue in an atrium’ corridors, it was found that over 90% could be saved of the energy spent using lighting controls (Chows et al. 2013). As well as, control strategies in offices can provide lighting energy savings rate of 60% (Xu et al. 2017).
In conclusion, from an environmental perspective, skycourts are a microclimate human- friendly space, which could improve human comfort levels through low-energy design guidelines.
2.2.2.2 Overview of Skycourts from a Social Perspective
There are three key benefits of skycourts from a social perspective; these look at the direct impact of skycourts on occupants’ interaction, social needs and wellbeing (Table 2-4).
The skycourt as a space for social networks: Skycourts could provide a medium for different levels of social interactions between people: public, semi-public and private interactions. For example, skycourts at the lower levels of buildings could enhance public interactions; skycourts at the middle levels and rooftops of buildings could develop semi- public interactions; and, interior spaces such as sky-terraces provide private social networks (Pomeroy 2014).
The skycourt as an enhancer of socio-physiological experience: Social design could be defined as a responsible design practice that focuses on the social dimension, by introducing the social needs and impacts of this approach, and then applying these on projects (Schwarz and Krabbendam 2013). Grounded on that, a skycourt could be defined as a socially responsible design element that emphasises the social good in the design to create social values.
The skycourt as an enhancer of psycho-physiological wellbeing: The skycourt could be defined as an element that enhances the psycho-physiological wellbeing of the occupants, and as a result improves the quality of living. This includes social, environmental and economic attributes. Skycourts could foster a sense of community and promote the community life (Kuo et al. 1998; Bay 2004). For example, it allows social interaction, which in turn has effects on the feeling of belonging and security. Skycourts could enhance exposure to natural features such as air, daylight, views, and greenery. These improve the quality of architectural spaces, which in turn offer beneficial psychological effects for occupants. Studies found that there is a relation between occupants’ health and the indoor daylight, vegetation, and the nature of views from and within the building. For example, daylight could foster beneficial effects in the health of people that live in buildings (Altomonte 2009). Furthermore, exposure to natural views contributes
substantially to occupants’ satisfaction and desire to keep in contact with the surrounding context, and augments wellbeing, attitude, mood, concentration and lower cholesterol levels (Honold et al. 2015; Altomonte 2009; Kaplan 2001) and reduces obesity, diabetes, and other chronic health problems (Lovell and Johnston 2009). In addition, spaces with indoor plants cause beneficial psychological changes such as stress-reduction (Dijkstra et al. 2008), mitigate pain (Bringslimark et al. 2009), and therefore, improve human
performance (Raanaas et al. 2011; Khan et al. 2005).Also, spaces with green plants were
preferred over the ones with no plants in offices (Shibata and Suzuki 2004).
Table 2-4. Benefits of skycourts in different studies from social perspective
The Skycourt as Enhancer of Socio-physiology and Psycho-physiology of the Occupants
(Pomeroy 2014) (Schwarz and Krabbendam 2013)
(Yeang 1999) (Honold et al. 2015) Skycourts enhance various levels of social interaction Spaces such as skycourts emphasise the social good in design to create social values
Skycourts are transitional zones located between the insides and the outsides of high-rise buildings to promote connection with the city
Exposure to different kinds of natural elements were related to lower cortisol levels
(Altomonte 2009) (Bringslimark et al. 2009)
(Dijkstra et al. 2008) (Kaplan 2001) Daylight can foster advantages to the quality of architectural spaces, bringing benefits to the occupants’ health
Indoor plants cause beneficial psychological changes such as stress-reduction and increased pain tolerance
Perceived stress was lower
and room
attractiveness was higher with plants
Settings in the view from the window contribute substantially to residents’ satisfaction with their
neighbourhood and with diverse aspects of their sense of
wellbeing
In conclusion, the skycourt is defined as a responsible typology that enhances social sustainability and the occupants’ experience in buildings.
2.2.2.3 Overview of Skycourts from an Economic Perspective
Skycourts provide several economic benefits in buildings (Table 2-5). Examples of these are the following:
The skycourt as a productivity enhancer: There is a direct relation between productivity and the indoor environment. It was found that productivity could be improved by 4% to
10% by enhancing the office environmental conditions such as indoor air quality and pollution (Clements-Croome and Baizhan 2000). Skycourts could enhance productivity as they provide an alternative informal working environment (Pomeroy 2007). Healthier buildings could reduce sick leave and increase productivity. For example, natural light, good ventilation, absence of organic compounds and appropriate temperature could result in happier and healthier workers (Miller et al. 2009). Skycourts could help in creating such environments.
The Skycourt as a means of reducing energy consumption: Skycourts could enhance utilisation of passive elements such as natural light and ventilation. In addition, a skycourt and its greenery could reduce heat gain and the ambient temperature (Jahnkassim and Ip 2006). Skycourts when acting as transitional spaces could attain wider limits of thermal comfort (Alonso et al. 2011). These could enhance potentials to reduce energy consumption.
The skycourt as an income generator: Skycourts could provide different functions to generate income. For example, they could be used to increase the rentable space, function as an observation deck, and provide food and beverage destinations. In addition, the skycourt could enhance the property value of the high-rise building (Pomeroy 2014).
Table 2-5. Benefits of skycourts in different studies from economic perspective
Skycourt As An Economic Enhancer Space- productivity enhancer
(Clements-Croome and Baizhan 2000)
(Pomeroy 2007) (Lambeth Council 2010) (Miller et al. 2009) Productivity could be improved by 4% to 10% by improving the office environmental conditions Skycourts provide networking space between workers A sky-roof with garden
has the potential for building energy savings to reduce annual heating and cooling loads
Spaces that improve happiness and health of workers attain reduction in sick time and an increase in productivity. Spaces that provide exposure to daylight and natural elements can create such environments
(Jahnkassim and Ip 2006)
(Ismail et al. 2011)
(Alonso et al. 2011) (Pomeroy 2014) The highest savings
in terms of energy performance are mainly attributed to features that have the highest solar control. Bioclimatic design elements such as skycourts show an improvement in energy saving Energy reduction in transitional spaces could be enhanced by minimising requirements of their comfort conditions Skycourts provide an iconic value to the building
In conclusion, from an economic perspective skycourts provide an energy reduction element in high-rise buildings that carries an iconic value to the building and increases the productivity of the occupants.
Figure 2-4. Definition of skycourts from social, environmental, and economic perspectives
Although skycourts can be beneficial in the environmental, social and economic aspects, they have their disadvantages. One main problem is fire safety. The vertical void feature of skycourt that contain several floors requires cautious consideration in the design process (Hung and Chow 2011). For example, smoke emitted from fire would spread more rapidly through such void compared to non-skycourt building (British Standard BS 9999:2017 2017). This would lead to human and property losses. Therefore, fire safety aspects for skycourts including design and management should be considered when designing skycourts in buildings. Other problems include solar collection through skycourt glazed facades and discomfort glares. This requests potential high energy demand to keep comfort level in these spaces (Göçer et al. 2006). In addition, skycourts reduce the total efficient area of the building as it displayed throughout many levels of the building.