How physical home workspace characteristics affect mental health: A systematic scoping review

3.4.1Noise, acoustics, and privacy

Table 3 shows the subjective and objective measures that were used for describing the physical workspace characteristics. All authors used subjective measures for noise, acoustics, and privacy. Several authors asked respondents to indicate their satisfaction with noise [5–7, 19, 24, 25] and privacy [7, 13, 23, 26]. In two papers, employees were asked to indicate how much noise annoyed them while WFH and which strategy they used to deal with these noise sources [27, 28], while another author asked teleworkers to indicate the annoyance caused by different noise sources before and after the COVID-19 pandemic [29]. Puglisi et al. [27] asked employees to rate their sensitivity and reaction to noise on a five-point scale. The Weinstein’s Noise Sensitivity Scale has also been used in two studied to assess teleworkers’ noise sensitivity [21, 22]. In another study, employees were asked to indicate why they chose a particular space to work from at home, which also included acoustic reasons (e.g., less noise or more privacy) [30].

Furthermore, several studies asked employees to indicate which noise sources they heard at home [21, 22, 27]. Torresin et al. [21, 22] adapted their question from the ISO/TS 12913-2 standard in both their studies to describe these noise sources (i.e., traffic noise, other noise from outside, natural sounds, human beings outside, other human beings present at home, neighbours, building services at home, building services of neighbours and common areas, and music/TV played by participants themselves). Another measure is the comfort level with background noise, building devices, and noise from outside the home [31]. Employees rated their comfort level on a five-point scale ranging from comfortable to uncomfortable [31], or from noisy to quiet [15]. In one study, respondents were also asked to rate the influence of noise on their mental health, well-being, and productivity [27]. Last, Boegheim et al. [19] objectively measured the sound pressure level by IEQ sensors that were placed on individuals’ home desks. Of all noise-related papers, most received a MMAT score of 50% (eight times), while only one received a score of 100% and one scored 0%. Overall, the quality of the noise-related studies is relatively high.

3.4.2Light and daylight

In several studies, satisfaction with the visual environment was calculated as the average score of satisfaction with natural light, electric light, and glare [5, 6, 24, 25, 28]. Fornara et al. [23] only included satisfaction with natural light in their study. Two authors measured satisfaction with the light environment in general [32, 33]. Umishio et al. [32] and Boegheim et al. [19] included the satisfaction with the illumination of the desk. Furthermore, Spano et al. [34] asked respondents to report their perception of the presence of sunlight on a three-point scale, ranging from not very bright to very bright, while Margariti et al. [15] asked them to rate the comfort of the light on a scale from dark to light. In another study, respondents were asked to indicate why they chose a particular space to work from at home, which also included access to daylight and sufficient artificiallight [30].

In only two studies objective measures of light and daylight were used [18]. In one study, the Troiano algorithm was described to calculate activity patterns, including activity levels, light (lux) exposure levels, and step counts. In another study, the illuminance level was measured by an IEQ sensor that was placed on employees’ desk at home [19]. Overall, most reviewed studies about light and daylight received a rather low MMAT score of 25% (five studies) or 50% (six studies), while the quality of only two studies was rated as 75% and of one studyas 100%.

3.4.3Thermal comfort and temperature

Of the thirteen studies about thermal comfort and temperature, five received a MMAT score of 25%, six of 50%, and two of 75%. The quality scores of these studies are relatively high. Satisfaction with the thermal environment was calculated as the average of the ratings for indoor air temperature and humidity [5, 6, 24]. In other studies, respondents were only asked to rate their satisfaction with the indoor temperature [7], or with the thermal environment in general [25, 33]. Furthermore, teleworkers’ evaluation of the indoor temperature was asked, ranging from cold to warm [15, 28, 31]. Salamone et al. [26] included both satisfaction with thermal comfort, employees’ preferences, perception, and interference with thermal comfort (i.e., ‘How does the thermal comfort of the environment interfere with your ability to work?’). Furthermore, Hiyasat et al. [30] asked respondents to indicate why they chose a particular space to work from, including the temperature at home. Last, in three studies, the indoor air temperature and relative humidity were objectively measured, using humidity loggers [32, 33] or wirelesssensors [19].

3.4.4Indoor air quality and ventilation

Most studies focussed on the subjective evaluation of the indoor air quality. In several studies, employees were asked to rate their satisfaction with the indoor air quality [5, 7, 14, 24, 25]. In one study, employees were also asked to rate their satisfaction with the ventilation in the home-work environment, on a five-point scale [7]. Furthermore, Margariti et al. [15] asked respondents to evaluate the air quality on a scale from poor to fresh. In another study, several subjective measures of the indoor air quality were used, including employees’ satisfaction, preferences, perception, and interference (i.e., ‘How does the indoor air quality interfere with your ability to work?’) [26]. Ekpanyaskul et al. [28] asked respondents to indicate environmental problems at home, including poor ventilation or air quality.

In one study humidity loggers were used to measure CO₂ levels and PM_2.5 mass concentration [32]. Boegheim et al. [19] used IEQ sensors to measure CO₂ levels. The quality assessment of the papers about indoor air quality and ventilation shows that most studies received a somewhat low score of 0% (one study), 25% (four studies), 50% (five studies), or 75% (two studies).

3.4.5Layout and design

The studies that regarded layout and design had an average quality. Two studies received a MMAT score of 100% and one of 75%. Table 3 shows that most studies used objective measures for layout and design. In two studies, respondents were asked to indicate whether they had a dedicated room for work activities, a dedicated workspace with other uses, or whether they worked in a variety of spaces [5, 31]. Bergefurt et al. [31] also asked teleworkers whether they had a shared or private workspace, and to indicate the size of their workspace (i.e., small, medium, large). Other studies asked respondents to indicate the housing typology [21, 22, 35]. Torresin et al. [21, 22] specified the housing typology as detached single-family house, semi-detached or terraced house, or apartment block. They also asked teleworkers in which room they worked, including the bedroom, kitchen/living room, kitchen, or in a studio. Furthermore, Fornara et al. [23] measured the crowdedness as the number of occupants divided by the number of rooms in the home (i.e., people-per-room ratio). Other objective measures include the size and the construction year of the house [35].

Subjective measures include employees’ satisfaction with the space at home (i.e., in general, space/square footage, privacy, natural light) [23] or the satisfaction with the layout [25]. Another measure is the importance of setting up a workspace separate from family members [14, 15]. Margariti et al. [15] pointed to the conflicting priorities that teleworkers have between domestic and work life, especially when their homes are small. Hiyasat et al. [30] asked respondents to indicate why they chose a particular space to work from, including the functionality of the space, such as changing the furniture or layout of the space. Last, Mäkikangas et al. [20] included six items to measure the functionality of the home workspace, of which the following are most relevant: ‘I have an adequate space at home for remote working’, ‘I have necessary equipment at home for remote working’, ‘I can find enough peace at home for working’, and ‘I can maintain a healthy work-life balance when working from home’.

3.4.6Biophilia and views

Overall, the quality of the studies regarding biophilia and views was rated somewhat low, with no studies receiving a MMAT score of 75% or 100%. Several objective and subjective measures have been used. Some authors asked respondents to specify if they had access to an outdoor space at their home [12]. Pouso et al. [16] specified the outdoor space as none, a balcony or patio, or a shared or public area, while Spano et al. [34] divided it into having a terrace with green, a courtyard with green, a garden, having access to more than one type of outdoor space, or residing in the countryside or mountains. In another study, respondents were asked to indicate the time they spent on average in their home garden, and to describe the composition of their garden (i.e., ornamental plants, fruits, vegetables, flowering plants, herbs and spices, or medicinal plants) [12]. Bergefurt et al. [7] subjectively measured employees’ satisfaction with the greenery at their home. Furthermore, Hiyasat et al. [30] asked respondents to report the reason to choose to work from a particular space at home, including visual access to a natural or organic environment.

Next to measures related to biophilia, several authors used measures for views outside. One measure was the type of views that could be seen from the work area at home, specified as few views or urban views, mixed views, or natural views [16]. Some authors also asked employees to indicate how much views they had from their work area (i.e., no green view, little bit of view, some view but without trees, some view with trees, most of the view, all of the view) [34] or to rate the dominating vegetation in their view outside [21, 22]. Last, in two studies, the satisfaction with employees’ views outside was measured [7, 25].

3.4.7Look and feel

Only two studies included a measure of look and feel. In one study, employees were asked to indicate the wall colour of their workroom, in which they could choose between blue-green, red-warm, or white-neutral wall colours [31]. Hiyasat et al. [30] asked respondents to indicate why they chose a particular space to work from, including the colours in the room. These studies received a quality score of 25% or 50%.

3.4.1Well-being

Table 4 shows the measures that were used for the mental health indicators. Two validated measures of well-being have been identified, namely the Health at Work Survey of WHO and the WHO-5 well-being index. In the Health At Work Survey, employees are asked to rate their well-being on a ten-point scale, ranging from low well-being to high well-being [7, 19, 31]. The WHO-5 well-being index consists of five questions related to the subjective psychological well-being of teleworkers [21, 22]. In another study, well-being was measured as quality of life, work happiness and satisfaction, work-life balance, and the absence of mental health problems while WFH [28].

3.4.2Stress

In several studies, no existing scale has been used to measure stress [6, 27–29]. Puglisi et al. [27] asked respondents to fill in what their main feeling was related to noise and added stress as an answer option. In one study, the Depression, Anxiety, and Stress Scale (DASS-21) was used. This scale consists of seven items per construct. The stress-scale consists of items to measure teleworkers’ difficulties to relax, their nervousness, arousal, ease of being upset or agitated, irritability or over-reactivity, and their impatience [12]. Another measure of stress is the Perceived Stress Scale (PSS), which consists of ten items measured on a five-point Likert scale. It measures the degree to which situations in teleworkers’ life are perceived as stressful [23]. Furthermore, the Patient and Health Questionnaire for Depression and Anxiety (PHQ-4) can be used to measure stress. Two items, namely ‘feeling nervous, anxious or on edge’ and ‘not being able to stop or control worrying’ are related to stress. In three studies, these items are combined with two items of the Stress and Worry Scale (i.e., ‘feeling stressed’, ‘ruminating or agonising over things’) [7, 19, 31].

3.4.3Productivity

Several studies used a five-point Likert scale to measure employees’ perceived productivity [5, 26, 30, 32]. In another study, the influence of noise on productivity was measured with five items on a five-point scale [27]. Furthermore, Kawakubo et al. [33] developed a method to measure the subjective evaluation of productivity with four factors, namely productivity of information processing, productivity of knowledge processing, productivity of knowledge creation, and comprehensive productivity. They used the Subjective Assessment of Workplace Productivity (SAP) questionnaire, which can be used for the subjective evaluation of productivity. Guo et al. [25] included a more objective measure of productivity by examining respondents’ speed and accuracy of completing a task. In another study, six attributes of productivity were measured, namely time management, effective work hours, work efficiency, work output, confidence in decision-making, and motivation to continue work [28]. Furthermore, Weber et al. [36] developed a measure to observe changes in productivity during the pandemic while WFH compared to working at the office. Last, the Health at Work Survey of WHO was used in three studies to measure productivity [7, 19, 31]. This is a ten-point scale ranging from low productivity to high productivity.

3.4.4Concentration

In most studies, no existing scales were used to measure concentration. Respondents were mostly asked to indicate the extent to which they could concentrate on their work while WFH [6, 14, 24, 32, 34, 35]. In one study, respondents were asked to indicate the disorders they suffered from during the COVID-19 lockdown period [35]. Lack of concentration was one of the answer options. Furthermore, Puglisi et al. [27] asked teleworkers to fill in what their main feeling was related to noise and added loss of concentration as an answer option. In three studies, an existing scale was used to measure concentration, namely the Checklist Individual Strength (CIS). These authors used a seven-point scale, ranging from low concentration to high concentration [7, 19, 31].

3.4.5Sleep quality

Some authors asked respondents to indicate how much trouble they experienced sleeping or how much their sleep was disturbed while WFH [6, 24, 29, 34]. Wütschert et al. [13] used an existing single-item scale for the evaluation of sleep-related problems that employees experienced during the past two weeks. Similarly, Bergefurt et al. [31] and Boegheim et al. [19] used the Single-item Sleep Quality Scale (PSQ). Other scales are the Athens Insomnia Scale (AIS) [32] and the Health at Work Survey of WHO [7, 19]. He et al. [18] used several measures to get an indication of employees’ sleep quality. They used online sleep diaries, the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), and actigraphy for objective measures. PSQI consists of seven constructs, namely subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. ISI is a seven-item survey which can be used to measure sleep difficulties and severity of insomnia symptoms. Last, actigraphy can be used to objectively monitor employees’ sleep, including sleep quality, wake-time activity, and intensity of movements in free-living settings.

3.4.6Fatigue

Only five studies investigated employees’ feelings of fatigue. Margariti et al. [15] used diaries and interviews, in which employees indicated to feel low, worried, positive, or slept well. These statements were used to get insights in respondents’ perception of fatigue. In three studies [7, 19, 31], the Checklist Individual Strength (CIS) was used, which consists of twenty items related to both fatigue and concentration. Respondents were asked to rate on a seven-point scale whether they felt tired, physically exhausted, weak, rested, etc. Last, Awada et al. [24] asked respondents to indicate their physical health status compared to the situation before WFH, of which feelings of fatigue was one symptom.

3.4.7Mood

Some authors did not use existing mood-scales, but asked employees to indicate if they experienced mood swings [6, 24], if noise affected their mood [29], or to indicate their moodiness [34]. Margariti et al. [15] used the Circumplex Model of Affect, which consists of the dimensions valence (i.e., pleasant-unpleasant or positive-negative), arousal (i.e., activation-deactivation or energetic-non energetic) and stance (i.e., low tension-high tension). The Plutchik’s wheel of emotions can also be used to capture teleworkers’ self-assessed emotions and mood [16]. Last, mood can be measured by the UWIST Mood Adjective Checklist, which consists of adjectives that can be summarized in the dimensions tense arousal (i.e., calm, relaxed – tense, nervous) and hedonic tone (happy, satisfied – sad, low-spirited) [7, 19, 31].

3.4.8Depression

Xiao et al. [6] and Awada et al. [24] did not use an existing scale to measure depressive symptoms. The other authors did use such scales, including the Depression, Anxiety, and Stress Scale (DASS-21) and the Four-item Patient and Health Questionnaire for Depression and Anxiety (PHQ-4). DASS-21 consists of three constructs, of which depression is one. It is measured by seven items, namely dysphoria, hopelessness, devaluation of life, self-deprecation, lack of interest or involvement, anhedonia, and inertia [12]. PHQ-4 consists of two short scales to measure anxiety disorders (Generalized Anxiety Disorder Scale, GAD-2) and depression disorders (Patient Health Questionnaire, PHQ-2) [7, 16, 19, 31].

3.4.9Engagement

In six studies the mental health indicator engagement was measured. Xiao et al. [6] and Awada et al. [24] asked teleworkers to rate their social engagement [7, 31]. Furthermore, the Oldenburg Burnout Inventory (OLBI) was used in three papers [7, 19, 31]. This scale consists of sixteen items, eight to measure (dis)engagement and eight to measure burnout. Employees are asked to rate these items on a four-point scale, ranging from strongly agree to strongly disagree. Last, Mäkikangas et al. [20] used the short three-item version of the Utrecht Work Engagement Scale. This scale consists of the items ‘I have felt bursting with energy while working’, ‘I have been enthusiastic about my work’, and ‘I have been immersed in my work’, which were all scored on a five-point scale.

3.4.10Burnout

In three studies, the Oldenburg Burnout Inventory (OLBI) was used to measure burnout with eight items that employees had to rate on a four-point scale [7, 19, 31]. In the fourth study, teleworkers were asked to indicate which disorders they suffered from during the COVID-19 lockdown, including eye disorders, headaches, concentration issues, and exhaustion [35]. Exhaustion has been scaled under burnout, because some authors (e.g., [37]) argued that burnout consists of emotional exhaustion, depersonalization, and lack of personal accomplishment.

3.5.1Noise, acoustics, and privacy

Table 5 shows the direction of significant relationships between all physical workspace characteristics and mental health. An upward arrow indicates a positive relationship, a downward arrow a negative relationship, and a cross indicates that the direction of the relationship has not been defined in the study.

Noise at home can be divided in indoor (e.g., systems and service, neighbours, family members, roommates) and outdoor noise sources (e.g., construction, traffic). Both indoor and outdoor noise disturbed employees’ sleep and negatively affected their mood. Especially noise by teleworkers’ children, partner or roommates made it difficult for them to concentrate on their job [29]. These sounds also had a negative effect on people’s well-being [22]. But noise from outdoors was also frequently mentioned to cause fatigue [15] and disturb teleworkers’ sleep [29]. Overall, uncomfortable noise levels distracted employees from their job, and reduced their well-being [31], and concentration levels [27]. The comfort of the acoustic environment was found to be important for employees’ psychological well-being [21] and concentration [32]. Torresin et al. [21] argued that the acoustic comfort could be improved by closing windows and doors, listening to music, and wearing noise-cancelling headphones.

Another predictor of mental health at home is satisfaction with noise. Those who were satisfied with noise felt less fatigued, depressed, stressed, indicated to have fewer mood swings and concentration difficulties [24] and felt more productive [25]. Boegheim et al. [19] also found that satisfaction with the noise level increased employees’ well-being and engagement, and diminished feelings of tension. During the COVID-19 pandemic, employees were less likely to report new mental health issues, such as depression, trouble sleeping, mood swings, decreased social engagement, and trouble concentrating, if they were satisfied with noise at home [6]. However, those who were dissatisfied with the privacy at home indicated more sleep problems [13]. Especially in shared rooms, noise annoyance was found to be higher, which could reduce teleworkers’ productivity, well-being, and concentration [21, 27].

3.5.2Light and daylight

Teleworkers’ satisfaction with the visual environment (i.e., natural light, electric light, and glare) influences their mental health. As Xiao et al. [6] argued, those who were satisfied with the visual environment had a smaller chance of reporting new mental health issues during the COVID-19 pandemic, including depression, trouble sleeping, mood swings, decreased social engagement, and trouble concentrating. Higher satisfaction with the visual environment also increases teleworkers’ productivity [25]. However, low levels of light exposure were found to be related to the misperception of sleep onset latency (i.e., discrepancy between subjective and objective sleep measures). This shows that low light exposure levels increase the chance of insomnia [18], while illuminance levels above 575lux lead to higher engagement [19].

Both access to daylight and artificial light are thus important for employees’ mental health. While satisfaction with artificial light significantly improves employees’ mood [7, 15], satisfaction with daylight reduces stress [7] and depressive symptoms [13]. Some teleworkers indicated that the daylight entrance at their home-workspace was suboptimal. Some of them relocated their desk to improve ambient conditions, while others used daylight-lamps to improve their mood and productivity [15]. Higher levels of sunlight, measured by the brightness level, were associated with lower self-reported moodiness, concentration, and sleep disturbance [34].

3.5.3Layout and design

Due to the COVID-19 pandemic, employees were obliged to WFH, even if their houses were not suitable for teleworking [5]. As Xiao et al. [6] indicated, those who did not have a dedicated workroom at home had a larger chance of reporting new mental health issues, including depression, trouble sleeping, mood swings, decreased social engagement, and trouble concentrating. In shared rooms, employees might have been more annoyed by noise, which reduced their well-being and productivity [27]. Some employees indicated to work in a variety of rooms at home, which might have reduced their productivity even further [5].

Furthermore, the spatial dimensions of the home were found to be important for teleworkers’ mental health. For instance, Fornara et al. [23] showed that satisfaction with the spatial dimensions of the home (i.e., in general, square footage, privacy, and natural light) reduced psychological distress. The spatial environment was also found to be important for employees’ concentration level [32]. Similarly, Muñoz-González et al. [35] argued that those who lived in single-family dwellings were less likely to experience concentration difficulties than those who lived in multi-family homes. They also showed that having access to a large living space (larger than 90m²) reduced the chance of mental problems, such as concentration issues and exhaustion. Mäkikangas et al. [20] included several home-office features to measure the home-office’s functionality, such as the adequacy of space and equipment to WFH, and the possibility to maintain a healthy work-life balance. They found that higher functionality of the home-work environment increased teleworkers’ work engagement significantly.

3.5.4Thermal comfort and temperature

One of the advantages of teleworking is having control over the indoor temperature at home, which might enhance teleworkers’ concentration level [14]. As Awada et al. [24] found, those who were dissatisfied with the temperature at home had trouble concentrating. Furthermore, thermal satisfaction (i.e., indoor temperature and humidity) [5, 33] and thermal comfort [26] were important for teleworkers’ productivity. Especially during the COVID-19 pandemic, satisfaction with the thermal environment might have prevented employees from developing new mental health issues, such as depression, trouble sleeping, mood swings, decreased social engagement, and trouble concentrating [6].

3.5.5Biophilia and views

In general, satisfaction with greenery predicted higher well-being [7]. Having access to greenery (e.g., a garden or patio) reduced teleworkers’ feelings of stress [12] and depressive symptoms [16]. However, those who did not have access to a patio or terrace suffered from a lack of concentration [35]. Spano et al. [34] argued that the presence of potted plants within the home-workspace was associated with lower self-reported moodiness and sleep disturbance.

Next to the presence of greenery indoors or outdoors, several researchers studied the influence of views outside on mental health while WFH. Generally, satisfaction with views outside was found to be related to higher concentration [7]. More specifically, having natural views outside was associated with fewer depressive symptoms, a more positive mood [16], and lower self-reported moodiness, concentration, and sleep disturbance [34].

3.5.6Indoor air quality and ventilation

Teleworkers who were satisfied with the air quality at home had less trouble sleeping and experienced less mental stress [15, 24]. They also experienced a more positive mood [15], rated their productivity to be higher [26], and indicated enhanced concentration due to better air quality [14]. As Xiao et al. [6] indicated, during the COVID-19 pandemic, the chance of teleworkers reporting new mental health issues, such as depression, trouble sleeping, mood swings, decreased social engagement, and trouble concentrating, was lower when they were satisfied with the air quality at home.

3.5.7Look and feel

Blue or green wall colours both have a positive effect on stress and mood, which indicates that employees felt more stressed, but also felt happier and more satisfied when their wall colours at home were blue or green [31]. Furthermore, those who changed the wall colours at home rated their productivity higher. The use of wall colours might positively affect teleworkers’ mood, which could, in turn, improve their productivity [30]. Other relationships between look and feel and mental health have not been found in the included papers.