Outdoor open spaces are important for sustainable universities because they accommodate outdoor activities and enhance the campus’s livability and vitality. The character of the outdoor space determines the quality of the campus [11,12]. Students’ success is aided by access to outdoor environments just as much as it is by on-campus amenities, such as the libraries, cafeterias, or university squares [13]. As such, designers and planners should consider outdoor spaces on university campuses to improve first impressions and create a holistic learning environment.

Various studies have proposed ways of improving outdoor spaces in universities to enhance comfort [14,15] and encourage students’ use of them for study, relaxation, contemplation, socialization, and entertainment [16]. These design strategies have placed emphasis on outdoor space layout [17]; location [18]; circulation and walking distance [19]; slope [20]; site furniture and seating [21]; shading [22]; and greenery and vegetation [23,24,25,26]. Studies have demonstrated the social value of public gathering spaces [15,27] and suggested ways of accommodating community belonging in courtyard spaces in universities by providing for users’ needs and preferences [13,28]. Researchers have developed frameworks for enhancing informal learning in these spaces [29,30]. Previous studies have largely discussed the principles of planning and elements of courtyard spaces on campuses, focusing on comfort, with little research [17,31] to address the elements of healthy open spaces and no guidelines for creating healthy, anti-virus open spaces.

The restrictions imposed to meet the threat of COVID-19 have highlighted the importance of outdoor communication and activities. Courtyard spaces are one of the most common outdoor open spaces on university campuses [28]. These spaces serve the needs of their users by providing scenery, as well as pleasing views for the buildings by which they are surrounded [17]. They also enable accessibility and freedom to engage in activities, contribute to strengthening interpersonal relationships, and improve the quality of university life [16]. Researchers discusses how to improve health and wellbeing and reduce infections in courtyard outdoor spaces in universities, with the goal of maximizing their potential as an anti-virus built environment to respond to future crises. Researchers also aim to explore students’ preferences and needs with regard to health and wellbeing and contribute to efforts to limit the spread of diseases by promoting healthy, open courtyard spaces.

Infectious disease transmission occurs in four major ways: direct contact, indirect contact, droplet transmission, and airborne transmission [32]. COVID-19 virus is being transferred between people via respiratory droplets and contact pathways, according to current evidence [33]. Airborne transmission of coronavirus may be possible in specific circumstances and settings [34]. The following sections explain the factors that contribute to the spread of viruses in the campus setting.

In general, urbanized areas in which societal interactions are concentrated generate favorable conditions for crowd diseases to spread. The novel coronavirus, for example, is a respiratory illness mainly transmitted via close person-to-person contact and through the respiratory droplets produced by the infected person when they cough, sneeze, or speak [34]. Controls to minimize infection rates have included ensuring distance is kept between people at all times (social distancing), mandating the wearing of personal protective equipment (PPE) [35,36,37,38]. The World Health Organization (WHO) has recommended the maintenance of an interpersonal distance of 1.5 m to 2 m to minimize the risk of infection. However, research supports the hypothesis of virus transmission over 2 m distance from an infected person [39,40]. The demand for social distancing could have implications for the design and planning of the spaces, not least due to increasing acceptance of distance learning, online shopping, and online connection [41]. User density can be significantly influenced by an open space layout, but social distancing should not be implemented without further research into capacity control, as well as user behavior observations and behavior modelling.

The link between COVID-19 frequency and urban design features remains a matter of debate, and the present data do not provide much clarity on how different design parameters influence infection rates [42]. One study in Poland found that an increase in population concentration was associated with a rise in COVID-19 transmission and mortality rates [43]. The availability of open green spaces in areas of high population density appears to be particularly important [44]. It is found that the smaller the area of green space in a city, the higher the confirmed number of infections [33]. It can thus be assumed that urban green spaces divide urban areas and reduce population density, thereby reducing the population’s infection rate. A study conducted in the United States concluded that a higher ratio of green spaces was linked with lower racial disparities in COVID-19 infection rates [8]. Furthermore, evidence suggests that a decentralized network of smaller green spaces—as opposed to a centralized space—makes it easier for users to interact with nature, improving physical and psychological wellbeing [45]. A decentralization strategy may foster horizontal expansion, necessitating a re-examination of planning theories to facilitate sustainable development and sufficient urban design [46]. However, the early findings suggest that planners should continue to advocate for compact patterns of urban expansion over sprawling alternatives, as several additional benefits of compact urban development are supported in studies [47,48,49]. The report on cities and pandemics states that public space assessments and programs are needed to support the creation of more equitably distributed public spaces. Moreover, flexibility and adaptability in the use of public spaces are crucial, particularly during a pandemic when public spaces must rapidly accommodate new needs [50]. The urban design elements can also contribute to the decrease of the virus spread—for example, flat surfaces may collect less dust, whilst white or light-colored surfaces may show dust clearly [41]. Even before COVID-19, there was growing attention and had been major advances in the use of smart solutions, to enhance the efficiency of urban operations and improve quality of life. This pandemic is now expected to boost smart city concepts [51]. Smart cities—and indeed smart university campuses—can use software applications to identify risk and gather information about the potential transmission of infectious diseases. These ICT solutions also have benefits for sustainability, as they reduce the need for reliance on other resources [52].

Virus survival is affected by several environmental conditions, include temperature, relative humidity (RHs), virus type (lipid or non-lipid), the presence of organic matter (e.g., saliva and mucus), and sunlight (ultraviolet light) [53]. Pollution also contributes to virus transmission [54,55]. Some experts believe that temperature and humidity are the most important drivers of airborne respiratory virus survival [56,57]. Virus survival decreases as temperatures rise [53]. The survival rate (half-life) of SARS-CoV-2 at 20 °C is higher than that at 40 °C [58]. Survival rates for viruses are higher in both low (10–40%) and high (60–100%) RHs compared to moderate RHs (40–60%) [59,60]. In general, viruses with lipid envelops types such as influenza and coronaviruses, will tend to survive longer at lower RHs (20–30%) [61]. The high air temperatures combined with high relative humidity levels have a synergistic impact on the inactivation of SARS-CoV-2 viability, while low temperature and low humidity promote the virus’s extended life on contaminated surfaces [62]. Based on examining the COVID-19 data and metrological data from official sources, it was found that each 1 °C increase in temperature was associated with a 4.8% decrease in confirmed daily cases [63]. However, several other studies argue that either there is no correlation between temperatures and COVID-19 cases, or temperature rise is associated with an increase in rates of transmission. For example, the spread rate of COVID-19 is not sensitive to ambient temperature variations in Iranian cities [64]. Other studies identified a positive relationship between COVID-19 spread and high temperatures in Milan, Oslo, and Jakarta, respectively [65,66,67]. In addition, it was also found that drier air favors the transmission of the virus [67]. Studies from Africa and the United States, as well as a global study of 100 countries, all found no significant relationship between humidity and COVID-19 transmission [68,69]. Sunlight is known to play a role in virus survival. Recent research findings have shown that dim light conditions help the virus to survive [70]. The UVB levels representative of natural sunlight quickly deactivate SARS-CoV-2 on surfaces, particularly on stainless steel surfaces [71]. Turning to other thermal parameters, further research is needed in relation to the impact of air movement, as the spread of viruses known to be associated with air pollution concentration and distribution. The distribution of air pollution through air movement can have both positive and negative effects on the rate of infection, depending on the studied area. A significant positive correlation with increased air movement was found, where a 1% increase in average air speed causes an 11.21% increase in COVID-19 cases in African countries [68]. However, a significant negative correlation with air movement and COVID-19 was found, where an increase in air speed was associated with decreased incidence of COVID-19 [72,73]. As has been established, air pollution strongly exacerbates the impact of illness on humans, and air stagnation is directly associated with elevated concentration of air pollution, specifically particle matter 2.5 μm (PM2.5) [74,75,76]. Whilst an increase in PM2.5 of 41.9% during episodes of stagnant air compared with non-stagnant air days, was reported [77], a low wind speeds were strongly correlated with elevated pollution concentration, in the southern part of the United States [75]. This establishes air stagnation as a threat, when dealing with the spread of viruses. In some contexts, COVID-19 cases and deaths are strongly linked with high levels of air pollution. Studies show that long-term exposure to air pollution can affect the respiratory system and increase human vulnerability [54,55]. For example, studies from different Italian regions show greater virus transmission in northern regions characterized by higher levels of air pollution [55,78]. Results from a large-scale study conducted in the Netherlands indicate that a 1 μ/m3 increase in PM2.5 concentrations is associated with 9.4 times more COVID-19 cases, 3.0 more hospital admissions, and 2.3 more deaths [79]. Hence, improvement in air quality could be a weapon in the fight against COVID-19 (and other pandemics). ‘Particular matter’ (PM) is a common term of air pollution. It has the greatest impact on individuals of any contaminant. Nitrates, sulfate, ammonia, sodium chloride, black carbon, mineral dust, and water are the primary constituents of PM. It is made up of a complex combination of organic and inorganic solid and liquid particles floating in air. While particles with a diameter of 10 microns or less can penetrate deep into the lungs, particles with a diameter of 2.5 microns or less are considerably more harmful to one’s health. PM2.5 has the ability to cross the lung barrier and enter the bloodstream [80].

Can university courtyard spaces be formed or reshaped to become disease-free, anti-virus environments that enhance the wellbeing of students? As noted above, the impact of urban environments on human health can be serious. One’s physical surroundings interact with environmental and social factors—promoting sustainability and health or exacerbating illness and disease. The characteristics of built environments vary within urban context, and new design guidelines for the open spaces in universities could be developed to increase health, health equity, and environmental sustainability. This research looks at the impact of the urban settings of university campus courtyards, focusing on the health and wellbeing of the students who use them. For this purpose, a case study campus is used. The investigation is intended to support the development of a model for public health spaces and strengthen support for planning that promotes urban health across university campuses.