A Study in Bedroom Living Environment Preferences of the Urban Elderly in China

Abstract

This study aims to analyze the indoor environment preferences of Chinese urban elderly, to create a living environment that is beneficial to the physical and mental health of Chinese elderly, and to enhance their sense of well-being. Based on an in-depth study of 306 urban elderly’s bedroom indoor environment preference in 21 Chinese provinces, using questionnaire method, this study concludes that: (1) Group characteristics: for urban elderly, the key words for bedroom color and lighting preference are low saturation, bright, warm tones and warm white light; personal characteristics such as the gender, physical condition, and education have a strong correlation with factors in the indoor living environment; (2) Physical environment preferences: gender presents the most significant potential effect on elderly physical environment preferences; (3) Established indicator system: the indicator system includes five main indicators of basic bedroom conditions, bedroom materials, bedroom colors, bedroom physical environment and other soft furnishings, and 22 sub-indicators. This study has some implications for guiding the design of elderly’s apartments and the bedroom environment, as well as effectively using the indoor environment to meet the physiological and psychological needs of the urban elderly.

1. Introduction

Since the 21st century, the world has been transitioning into an aging society, and China’s aging problem is particularly serious [1]. Over the last 20 years, the proportion of China’s elderly population aged 60 has increased by 8.7 percentage points, which are 5.1 percentage points higher than the global average and 2.5 percentage points higher than developed countries. China currently has the world’s largest elderly population [2], with 18.70% of the elderly aged 60 and above and 13.50% of the elderly aged 65 and above [3]. It is predicted that by 2025, the proportion of the elderly population in China will reach 25%, which means that there will be one elderly person in every four people. With such a large number of the elderly, their physical condition and mental outlook will be directly related to the stability of the whole society [4]. Furthermore, the aging of the population is inextricably linked to social sustainability. On the one hand, social sustainability is a system project based on population. Meanwhile, population aging has direct effects on population structure, development and demand. On the other hand, population aging is also an inevitable result of sustainable social development [5]. The elderly face physical decline, changes in activity focus, narrowing of social interaction, slower pace of life and obsolescence of knowledge and skills, causing them to have diverse needs for a bedroom living environment than the young. The elderly living conditions are often the most basic and prominent of the aging problems. The demand for an age-friendly living environment is expanding from material needs to the spiritual level, providing a living environment that is conducive to the physical and mental health of the elderly in China has become the focus of the whole society [6]. As a result, a positive attitude toward aging is the only way to turn the pressure of population aging into a driving force for sustainable socio-economic growth.

Previous research has concentrated on the following aspects: (1) Research related to intelligent age-friendly housing. A new round of technological revolution is emerging, with information and communication technology at its core, driving fundamental changes in all aspects of human economic and social life. Smart care for the elderly was created by combining the elderly with the Internet, the Mobile Internet, and the Internet of Things. There have been numerous studies in recent years on the design and planning of aging-friendly housing and facilities using intelligent technology or with the help of Internet big data and cross-application of ergonomics, architecture, and other disciplines [7,8,9]. Additionally, aging-friendly housing has gradually become a focus of attention in academia and industry due to the increase in the number of elderly people living alone so that help the elderly create a comfortable living environment [8]. (2) Research related to the physical environment of indoor spaces. On the one hand, focusing on the overall quality assessment of the indoor environment [10,11], scholars provide theoretical support for the design of senior housing by studying the impact of the overall physical environment on the elderly population in senior living institutions or senior housing [10]. On the other hand, they focus on a single element of the physical environment, such as sound, heat, light, and air quality, evaluating a single element of the physical environment in senior housing and then making recommendations for optimization [12,13,14]. Meanwhile, some scholars have researched the relationship between two physical environments. For example, Mendes et al. focused on the assessment of indoor environmental variables (IAQ and TC) in the ECCs that might influence elderly comfort and well-being and interact with their already existent chronic diseases [15]. (3) Research related to bedroom living environment preference of the elderly. With the improvement of economic living standards, attention must be paid to both the material and spiritual needs of elderly people. Studies on the subjective assessment of elderly people’s satisfaction with their housing, their needs, and their preferences for housing design have gradually become a research focus [16,17]. Studies usually combine physical measurements of the indoor environment and subjective evaluations to assess senior housing and make recommendations regarding the comfort, convenience, and safety of senior housing [17].

Currently, indoor studies tend to involve the entire living environment and less often focus on a single bedroom. Bedrooms are the most important resting spaces in the elderly entire living unit, which serve not only as sleeping areas, but also as places to nourish body and mind, enjoy hobbies, deeply affecting the quality of life of the elderly in their old age. Several studies have investigated the design of local factors for the elderly bedroom, with a focus primarily on the physical environment of the bedroom and the bedroom smart home and smart systems [18,19,20]. For example, using a wrist-worn sleep tracker, Yan et al. [19] used physical measurements to examine the thermal environment as well as ventilation in the bedrooms of elderly subjects in order to investigate the thermal environment and ventilation in the bedrooms of elderly subjects and their relationship with summer sleep quality. Based on the special psychological and physiological characteristics of the elderly and their needs for the bedroom environment, Liu et al. [20] introduces intelligent control systems into the furniture design of the elderly bedroom space and explores its advantages, disadvantages and feasibility. As a result, most of the existing studies focus on the physical environment of the bedroom and the design of the intelligent bedroom, with less research on bedroom decoration, materials, furniture, furnishings, and lighting. Therefore, this paper aims to identify the preferences of the elderly for bedroom furniture, decoration, and physical environment in order to develop a humanized bedroom environment with cultural sensibilities that are conducive to their physical and mental well-being.

According to the positivist methodology of sociology, many social phenomena are random phenomena. Statistics is a mathematical tool devoted to the study of these kind of phenomena, which provides a series of quantitative methods for studying them. The manifestation of scientific positivism in sociological research is the use of large-scale questionnaires to understand a wide variety of social facts and to provide empirical materials for theoretical research [21].

The aim of this paper is to study the preference and reasons for the bedroom indoor environment of the urban elderly in China. Based on the philosophical stance of scientific positivism, this paper adopts a questionnaire approach, defining the framework of the questionnaire based on literature studies, with individual interviews to supplement the description of the questionnaire. The article collects data on urban elderly bedroom living environment preferences from 21 provinces, autonomous regions and municipalities directly under the central government in China, using descriptive analysis, Chi-square independence test and interaction analysis to reveal the association between each potential influencing factor and urban elderly bedroom living environment preference, as well as suggesting how they should be designed. The objectives are to achieve the following tasks:

• i.. To investigate overall preference of bedroom indoor living environment of the Chinese urban elderly.

• ii.. To study the relationship between population characteristics, design factors and elderly indoor environment preference.

• iii.. To provide recommendations for designing bedroom living environments for Chinese urban elderly.

2. Methodology

2.1. Research Approaches

Based on literature research and semi-structured interview method, this study establishes the index system of the elderly bedroom elements and designs the elderly bedroom preference questionnaire. In this research, the empirical analysis consists of the following three parts: (1) Descriptive analysis: The results obtained from the collected data are briefly described through descriptive analysis, which is used to analyze the overall preferences of the elderly for the indoor environment. (2) Chi-square independence test: This study used categorical data as the data form in questionnaire. The chi-square test, an important analytical method, is designed to analyze the relationship between two categorical data. Therefore, this study applied the chi-square test for independence to conduct the data analysis. It is aimed to determine whether there is a significant correlation between each potential influencing factor and the bedroom living environment preference of the elderly by the magnitude of the p-value. (3) Interaction analysis: When the p-value was less than 0.05, the independent chi-square test was passed. By using interaction analysis, this study further analyzed the percentage between different attributes and the indoor environment preference of the elderly, which is to compare the specific differences in the indoor environment preference of elderly people under different demographic characteristics and designs. Figure 1 shows the research methodology of this study.

2.2. Research Objects

Under international regulations, people over the age of 60 are considered elderly. In spite of China’s late entry into aging society, its elderly population is large and aging is a rapid process [22]. Some of the personality traits of the elderly in China include loneliness, anxiety, reduced activity, reduced adaptability, recalling the past, and a preference for comfort and security [23]. These characteristics determine that they have unusual and special needs for the living environment. Different cultural backgrounds and historical processes have given birth to very different concepts and models of aging in contemporary China [24]. Compared to the Western elderly who pursue more material and spiritual independence [25], the Chinese concept of old age is influenced by Confucianism and the traditional “filial culture”, with the concept of “raising children for old age” being deeply rooted [26], so they tend to be more dependent on their children. However, the contemporary Chinese children often have difficulties in balancing the interaction and other needs of the elderly. Although nursing homes and time banks are developing, they are still relatively immature at the moment. Family pension mode remains the main mode of pension for Chinese seniors. In the context of the unique Chinese elderly personality and the lack of family interaction, it is important to study the living environment preferences of Chinese urban elderly and increase the comfort of their physical and mental experience through the design of living space.

2.3. Data Analysis

The questionnaire was distributed online using Questionnaire Star (a professional online authoritative questionnaire platform widely used in enterprise and university research [27]) from 19 January to 20 February 2022, which coincided with the Chinese New Year holiday, when children returned to their hometowns for the New Year and could assist the elderly in filling out the questionnaire, which was conducive to improving questionnaire quality. Respondents were able to complete the questionnaire by scanning the QR code with We Chat 8.0.17.

Due to the large difference in economic development and ideology, this study only issued questionnaires for inland China (excluding Hong Kong, Macao, and Taiwan), and questionnaire data were collected from 16 provinces, 2 autonomous regions, and 3 municipalities directly under the central government, with a high coverage of 61.76% of the surveyed areas, and 306 valid questionnaires were collected. The distribution is presented in Figure 2.

2.4. Establishment of Indoor Environment Preference Index System and Questionnaire Design for Elderly People’s Bedroom

In this study, by combing the indoor environment elements contained in the buildings of senior housing and nursing homes with the supplement of semi-structured interviews, we established an index system of elderly people’s bedroom living environment preference by dividing the bedroom elements into five parts: basic bedroom conditions, bedroom materials, bedroom colors, bedroom physical environment and other soft furnishings [28,29,30,31,32,33,34,35,36,37] (see Table 1). According to this index system, a questionnaire was designed. The questionnaire was divided into two major parts, the first part was the demographic characteristics of the respondents, including six aspects such as gender, age, occupation, monthly income, education, and physical condition; the second part was 32 questions related to the bedroom living preferences of the respondents, and the questionnaire had a total of 38 questions.

To help the elderly understand the questions more clearly and intuitively, some questions were supplemented with pictures; to avoid sequential effects, the questions and options were set in random orders. Before the questionnaire was officially distributed, 36 small-scale pre-surveys were conducted with professionals in related fields and the elderly around us, and the questionnaire items were further modified and improved based on the interviews and responses after the survey to ensure that the elderly could clearly understand the content of the questions. The average time taken to complete the questionnaire was 10 min. At the end of the questionnaire, a random bonus reward and a sharing bonus reward were provided to increase the spread of the questionnaire and promote the enthusiasm of filling out the questionnaire.

3. Results

3.1. Descriptive Analysis

Of the 306 respondents, 71% were female, which is basically in line with the reality that women account for 68% of the urban elderly population in China [38]. About 40% of the respondents have a bachelor’s degree, about 51% are employed in enterprises and institutions, and about 13% are farmers who later move to the city with their children to retire. The average age of the sample is around 68 years old, and about 61% of them are between 60 and 64 years old. About 41% of them have a monthly income of RMB 4000–7000 (US$ 596.8–1044.4) for their pension, which is higher than the national per capita disposable monthly income of RMB 2927 (US$ 436.7084) in 2021. This indicates that the urban elderly in China is relatively affluent materially, which objectively supports the statistics that 95% of the elderly say they need “spiritual companionship” and “spiritual care” in their old age [39]. Among the samples, 43.14% are in good health. In summary, early retirement, good health, and more “crystal intelligence” are their more prominent characteristics [40]. Details of the socio-demographic characteristics of the tested individuals are presented in Figure 3.

3.2. Overall Analysis of Bedroom Living Environment Preferences of the Elderly in Urban China

3.2.1. Preference for Bedroom Basics

• (1). In terms of floor, because of the degeneration of motor functions [41], and considering the convenience of travel, 58.17% of them choose to live on lower floors (1–3 floors). Only 1.96% of them choose super high floors (above 20 floors), probably due to the relatively thin air on high floors, which can easily cause dizziness due to fear of heights.

• (2). About bedroom orientation, China is located in the northern hemisphere, the house is more conducive to sunlight, while having the advantages of warm in winter and cool in summer. Therefore, 75.82% of the elderly prefer to face the south of the room.

• (3). For the bedroom area, more than 50% of the elderly prefer to live in a room of 15–24 square meters. Area less than 15 square meters, the elderly activities and storage space will be squeezed. If the bedroom area exceeds 24 m², it will appear empty and insecure.

• (4). In terms of decoration style, the elderly prefers modern minimalist style (51.63%) and new Chinese style (37.91%). They have the characteristics of simplicity, naturalness and calm atmosphere, which are in line with the character traits of nostalgia and pursuit of stability of the Chinese elderly, reflecting the return to the basics after reading all the prosperity.

3.2.2. Preference for Bedroom Materials

• (1). About door materials, more than 50% of the elderly prefer solid wood doors to metal and glass doors.

• (2). In terms of flooring materials, wooden floors have the advantages of non-slip, deep color and dirt resistance, mild and comfortable foot feeling and reducing pressure [42]. Therefore, the vast majority of the elderly (87.58%) prefer wooden floors.

• (3). For wall materials, wallpaper (30.72%) and latex paint (28.76%) are the most preferred materials by the elderly.

• (4). In terms of sofa materials, the elderly prefers cloth (43.14%) and leather (36.6%) and other comfortable soft materials.

• (5). About curtains, cotton and linen are breathable and environmentally friendly, which are loved by the majority of seniors (63.4%).

• (6). In terms of bedding materials, cotton material has a comfortable, anti-itch, skin-friendly and anti-static properties. Therefore, it is more preferred by the elderly (86.27%).

3.2.3. Preference for Bedroom Color and Lighting

• (1). In terms of color, 73.86% of the elderly prefer rooms with low saturation.

• (2). About brightness, because of the declining of pupillary as people age [43], the brightness needed increases, and bright light can promote physical and mental health [44], most of the elderly (85.62%) would prefer a bright room.

• (3). As for the choice of warm and cold hue, 77.78% of the elderly chose rooms with warm hue, because warm hue can give them a peaceful and warm feeling, which is more in line with the psychological needs of the elderly. At the same time, the elderly will avoid the warm light that feels stimulating and hot and the cold light that is cold and lonely in the choice of light color, and choose the warm white light with moderate color (69.28%).

3.2.4. Preference for Bedroom Interior Decoration and Furnishings

• (1). In the choice of lamps, the elderly prefer chandeliers (43.14%) and decorative lamps (32.68%) with a wide range of lighting.

• (2). In the type of lamps, simple and environmentally friendly ceiling lamps that do not hide dust and are easy to clean are more popular (63.4%).

• (3). As for the choice of wall hangings, Chinese paintings (35.95%) and oil paintings (26.8%) are preferred by the elderly.

• (4). In the type of clocks, the majority of the elderly choose the pointer clock (76.47%) and prefer to hang the clock on the wall (84.62%). This may be related to the nostalgic feelings and habits of the elderly for many years, and there are significant differences with the preferences of young people.

• (5). In the choice of practical crafts, ceramic ware (64.05%) is the most popular among the elderly, not only for the reason that the porcelain is part of traditional Chinese culture, in line with the aesthetic views of the country, but also because the elderly has experienced great storms, porcelain shows the stability, elegance and quiet and the state of mind of the elderly more compatible.

• (6). In terms of greenery, simple and well-kept foliage plants (52.29%) are more popular among the elderly, and most of them have 1 to 5 pots of flowers.

In other aspects, regarding the choice of bed softness, most of the elderly would choose a hard bed; for heating, a majority of the elderly chose radiators and floor heating; on air purification, almost all seniors would choose natural ventilation; about noise, more seniors (69.93%) hate outdoor construction noise; in terms of window type, 58.82% of the elderly prefer floor-to-ceiling windows; as to the window view, garden greenery (43.14%) and leisure pavilion (41.83%) are the most popular among the elderly.

3.3. Correlation and Impact Analysis of Indoor Environmental Preferences of Chinese Urban Elderly

To complement the descriptive analysis, statistical analyses were conducted. A chi-square test of independence was applied to find associations between various potential elements and bedroom living environment design.

3.3.1. Preference for Bedroom Basics

• (1). The Relevance of Color and Bedroom Living Environment Design

Through the interactive analysis of brightness with window types and lamp types, Figure 4a,b is obtained, which reveals a significant effect of brightness on window types and lamp types (p < 0.001). The elderly who prefers brightness prefer chandeliers and decorative lights with a wide range of illumination and floor-to-ceiling windows with the largest glass area. Similarly, the color degree has a significant effect on the decoration style (p < 0.05), and by Figure 4c, it is found that the group of seniors who prefer high saturation prefer the new Chinese style, while those who prefer low saturation prefer the modern minimalist style of decoration. Finally, cool and warm hue are also statistically significantly correlated with flooring material (p < 0.001). Figure 4d shows that the elderly who prefer cooler hue prefer marble flooring material, while those who prefer warmer hue prefer wood flooring.

• (2). The Relevance of Other Factors to the Design of the Bedroom Living Environment

Cross-tabulating the other factors with the interior environment design, the preference of mattress softness among the elderly is statistically significantly correlated with sofa material, decoration style with overhead light type and greenery type with bedding pattern. Using Figure 5a–c, the following results are obtained: (1) The elderly has different preference for furniture softness and firmness. The preference of mattress softness ranged from hard to soft groups, and the preference of sofa material showed a change from wood, leather, and rattan to fabric; (2) There is a high consistency in the choice of decoration style and type of overhead lighting among the elderly. The elderly who prefers European style prefer European chandeliers, and those who prefer modern minimalist style prefer ceiling lights; (3) According to the preference of bedding patterns and greenery types, the elderly can be divided into three categories. The first category of elderly people prefer lively and colorful patterns, prefer plants with ornamental fruit, plants with ornamental flower and floral pattern bedding; the second category of the elderly prefer regular patterns, prefer plants with ornamental foliage and lattice striped bedding patterns; the third category of elderly people prefer simple patterns, prefer plants with ornamental stem and simple solid color bedding patterns.

3.3.2. Correlations between Demographic Characteristics and Bedroom Living Environment

• (1). Correlations of Gender with Basic Bedroom Conditions, Sound, Light, Heat and Air

Cross-tabulations of gender with seven different dependent variables of basic bedroom condition and sound, light, heat and air are analyzed. The results show that gender is statistically associated with the six dependent variables of floor and decorating style (p < 0.05). Gender and lamps pass the chi-square test (p < 0.001).

Among the personal characteristics, gender plays a significant influence on the choice of floor and decoration style preference of the elderly. In Figure 6a, it can be seen that women have a significantly greater preference for lower floors (1–3 floors) than men, while men have a significantly greater preference for higher floors (10–20 floors) than women. Light and view are the concerns of men in choosing floors, while ease of movement and sense of security are the concerns of women. As it can be seen in Figure 6b, there are significantly more women than men who prefer the new Chinese style, while there are significantly more men than women who prefer the modern minimalist style. This may be due to the fact that men prefer rational thinking and want open and clean space, while women will be more emotional and prefer a warm and rhythmic decoration style.

According to Figure 6c–g, the specific differences in sound, light, heat and air preferences of the elderly by gender can be explained. Men pay more attention to the quality of light environment than women, and women pay more attention to the quality of sound environment than men; while for noise, women hate outdoor road traffic noise more, and men hate outdoor construction noise more; for the ways of heating, men prefer floor heating and women prefer the radiator; for air purification methods, women prefer greenery more and men are more interested in air purifiers and air fresheners; regarding lamps, women prefer chandeliers and table lamps, while men favor standing lamps.

• (2). Relevance of Gender with Bedroom Decorations and Materials

The cross-tabulations of seven different dependent variables of gender and bedroom decorative arrangements and material materials are analyzed. The results show that gender is statistically associated with bedding pattern and door material (p < 0.05). Gender plays a significant influence on the choice of five dependent variables, including closet and greenery (p < 0.001).

Figure 7a–c shows the differences in the effects of gender on bedroom decorative arrangements in the elderly group. In terms of closets, men prefer the space-saving built-in closes, while women prefer the independent closets that can be moved; the choice of greenery, men prefer plants with ornamental flowers and fruits, women prefer more plants with ornamental foliage; on bedding patterns, men prefer floral patterns and women favor plaid stripes.

Figure 7d–g shows specific differences in the influence of gender on materials used in older adults’ bedrooms. For door materials, males prefer metal doors and females prefer solid wood doors, which are mainly influenced by biological instincts and primitive social division of labor. As for the flooring material, women prefer wooden flooring and men prefer marbles as well as carpets. Regarding wall materials, women prefer wallpaper and men more prefer wall coverings and tiles. For sofa materials, women prefer fabric sofas and men prefer wooden sofas. Due to the different physiological structure, women are more sensitive to the feeling of cold than men, so women tend to choose warm fabric sofas.

• (3). Relevance of Age, Occupation and Bedroom Living Environment Design

Age is cross tabulated with four different dependent variables. The results show that age is significantly correlated with the four dependent variables, including window view (p < 0.05).

The differences in decoration styles and bedding patterns among the elderly of different ages are shown in Figure 8a,b. In terms of decoration style, seniors aged 65–69 years prefer the new Chinese style and those aged 75–79 years prefer the modern minimalist style. The preference for Japanese style and European style decreases with age, which may be influenced by the recognition and acceptance of foreign cultural styles; for bedding pattern, the elderly aged 60–69 prefer plaid stripes, those aged 70–74 prefer floral patterns, those aged 75–79 prefer simple solid colors, and those aged 80 and above prefer cartoon characters.

The interaction between age and window view and closet was analyzed. Age and window view and wardrobe passed the chi-square test. The specific differences in window view and wardrobe preferences by age group are shown in Figure 8c,d. The 60–69 years old prefer garden greenery, the 70–74 years old prefer neighborhood panoramic views, the 75–79 years old prefer diverse water features, leisure pavilions and fitness activity centers, and the 80+ years old love children’s activity centers. Probably due to ageing, the elderly will increasingly prefer moving scenery and will also pay more attention to leisure and fitness. As for the closet, the elderly aged 65–69 prefer built-in closets, while those aged 75–79 want multi-functional closets.

A cross-tabulation of occupation with four different dependent variables is analyzed. The results show that occupation had a significant effect on roof lamps, decorating styles, bedding patterns, and types of greenery at p < 0.001. As shown in Figure 9, the elderly working in the commercial/service industry prefer luxurious and rich European decorative style, European chandeliers, flower-viewing plants and stem-viewing plants, and simple solid-color bedding patterns; the elderly working in professional and technical jobs prefer geometric Japanese decorative style and practical and environmentally friendly ceiling lights; the elderly who work in agriculture prefer ordinary chandeliers, plants with ornamental fruit, plants with ornamental flower and floral bedding patterns; while the military have a strong sense of identity and belonging to Chinese culture, prefer new Chinese decoration style and Chinese chandeliers, and prefer leaf-viewing plants and stem-viewing plants.

• (4). Correlations between Academic Qualifications and Bedroom Living Environment Design

The cross-tabulations of education with the three different dependent variables are analyzed. The results show that at p < 0.001, education is significantly correlated with the three dependent variables, including the types of luminaire. As shown in Figure 10, the elderly with higher education would be more likely to prefer premium atmospheric lamps and higher acceptance of maps, photos, and cartoon patterns. Specifically, the elderly with junior high school or below prefer table lamps, Chinese paintings and floral-patterned bedding; seniors with college prefer chandeliers and simple solid-color patterned bedding; the elderly with bachelor’s degree prefer decorative lamps, oil paintings and plaid stripe pattern bedding; the elderly with master’s degree and above prefer standing lamps, maps and photos and bedding with cartoon patterns.

• (5). Correlations between Physical Condition and Bedroom Living Environment Design

Cross-tabulations of physical status with seven different dependent variables are analyzed for interaction. The results show that body condition is statistically associated with three dependent variables such as lightness and darkness at p < 0.05. In addition, at p < 0.001, body condition is significantly associated with four dependent variables such as heating method. It can be found through Figure 11 that the elderly with good health pay more attention to the quality of acoustic environment and prefer floor heating and decorative lights; the elderly with normal health pay more attention to the quality of air environment and prefer chandeliers; the elderly with ill health may pay more attention to the quality of light environment and prefer desk lamps, heaters and darkness of rooms due to their susceptibility to light stimulation.

In addition, the elderly with relatively ill health condition prefers harder material sofa. At the same time, health status will have an impact on the subjective feelings of older people, and those with ill health status are more likely to have negative emotions [45], so they will prefer lively bedding patterns. In contrast, the elderly in good health prefers simple solid-colored bedding, wallpaper, and fabric sofas; the elderly in normal health prefer simple solid color bed pattern, wall cloth and seaweed mud and leather sofa; the elderly in ill health prefer more lively flower patterns, seaweed mud, latex paint and rattan sofas.

4. Discussion

4.1. Aging Needs and Well-Being of the Elderly

By improving the overall physical environment of elderly-friendly residential buildings, the improvement of interior environment design in bedroom for the elderly is not only an important part to meet the current living needs of the elderly group, but also an important step to create an elderly-friendly living environment [8,10]. Although there have been a number of conceptual consensus and positive examples based on health-assisted design for urban elderly indoor environments, current research on age-appropriate housing has mainly explored the building performance and overall indoor environmental quality of elderly housing from physical environment measurements [46,47,48], with limited realistic explanatory power.

Based on the preference for bedroom living environment of urban elderly population in China, this study explores what kinds of preferences the elderly people have, and the correlation between their design preferences of the bedroom living environment and demographic characteristics, so as to enrich the relevant research on the indoor environment design of elderly-friendly residential buildings. From the perspective of basic functions, this study expands the focus of designing and planning for elderly-friendly housing and facilities [7,9]. It also responds to the positive relationship existed between the improvement of economic development and the satisfaction of spiritual needs of the elderly [16]. Furthermore, it comprehensively analyzes elder people’s specific spiritual needs according to the indoor environment design of their bedrooms. From the perspective of preference factors, this study takes the house furnishings, lighting for decoration and various materials and textures in a single bedroom space into investigation. On the one hand, it enriches the composition of the physical environment elements of the elders’ residence [11,12,13], on the other hand, it supplements the hardware requirements which need paying attention to the interior design of the bedroom environment of an elderly-friendly residence.

On these bases, this study further analyzes the demands for old-age provision, which is ought to be satisfied by the design of the bedroom living environment based on Maslow’s hierarchy of needs. The results are summarized as shown in Figure 12.

• (1). Physical Need

Physical health is the most basic old-age care need of the elderly. This study found that elderly people attach much importance to long light duration, large area and comfortable and environmentally friendly materials. Fu et al. found that the most comfortable lighting range for elderly people to read during daytime was 600–800 lx, and 700 lx was optimal [49]. Meanwhile, a study showed that both higher temperature and CO2 concentration were negatively correlated with better sleep quality in the elderly [19]. Therefore, in the design of the living environment, some key factors such as temperature, noise, air quality, and light deserve consideration, which are all directly related with elderly people’s physical health.

• (2). Safety Need

The elderly population needs a sense of security on a psychological level. As they age, all physical functions of the elderly gradually decline, with degeneration in the sense of touch, taste, smell and vision. Declining autonomy may cause older adults to feel helpless, while weakening care from family and lack of spiritual care from children may increase their insecurity. There has been research suggesting that color therapy is a widely accepted treatment for depressive symptoms in older adults. For example, healthy older adults respond positively to a cool blue monochromatic color scheme, while depressed older adults respond actively to a contrasting blue-yellow/red cool color scheme [33]. The elderly prefer warm colors and bright lights, behind the mapping is their enhancing need of feeling safe.

• (3). Social Need

For the elderly, social pleasure plays an important role in their later life. Once the elderly leave the workplace and return to the family, the social activities they can take part in are becoming less and less. The pressure brought by the great changes in family and interpersonal relationship will make them feel depressed, dissatisfied, even desperate, such feelings of imbalance their well-being [50].

• (4). Esteem Need

Everyone desires to be respected and accepted by others, and so do the elderly. It is this need that reflects their pursuit of a better life, higher human dignity and self-worth.

• (5). Self Realization

The elderly hope that they still have the ability to adapt to society and that this positive energy will play a regulating role in their later life. Compared with the planned economy system, the socialist market economy system emphasizes self-actualization and shows the tendency of realism. Under the influence of this, more and more elderly people pay attention to their personal feelings and spiritual needs, and the level of needs is obviously raised. The preference of the elderly for porcelain, Chinese painting and oil painting also shows the lofty spiritual realm of the elderly in urban China.

4.2. Suggestions

Based on the results of the statistical analysis of this study, the following suggestions are made:

• (1). Suggestions for interior decorators

Under the premise that material living conditions have improved significantly, Chinese elderly people have changed from focusing more on society and others to focusing more on their own health and destiny. For interior decorators, the design of living environments for the elderly needs to consider the physical conditions and health needs of the elderly as much as possible. Specific recommendations are as follows.

• • (1). On the bedroom furniture, the sofa is best to be hard to reduce the lumbar burden of the elderly.

  • (2). In terms of style, try to choose a simple and generous decoration style, simple and practical furniture, and ceramic utensils that represent “stability and elegance”.

  • (3). For material selection, flooring materials should be non-slip and mild footing wood flooring materials, and bedding materials should be skin-friendly cotton materials.

  • (4). About light, studies conducted in Western countries have shown that proper natural light exposure contributes to good quality sleep in the elderly and helps maintain their health [51,52]. This study further found that for the elderly with different physical conditions, different light intensities should be provided. In order to ensure that the elderly enjoy sufficient light, the floor-to-ceiling windows are a better choice. chandeliers or decorative lights in lamps and lanterns will help to expand the area of natural and artificial light. However, if the elderly are not in good physical condition, they should not be stimulated by light, and it is necessary to arrange a dark room and put a lamp on the beside table to help the elderly turn on the light more conveniently.

• (2). Suggestions for elderly care service workers

For elderly care service workers, apart from paying attention to the physical health of the elderly, more attention should be thrown into the mental health and spiritual satisfaction. Interior decoration should try to create a warm and comfortable atmosphere to reduce their senses of helplessness and insecurity.

• • (1). Colors in bedroom should be low-saturated, bright and warm, so that the elderly can feel soft and warm.

  • (2). Based on a study by Scheidt et al. [53], homelike decoration can help residents to reduce nostalgia and improve their sense of belonging to their home. Therefore, if the elderly are rather emotional and nostalgic, meaningful photos can be hung, which can be displayed to create a living environment full of affection and reduce their loneliness.

As the basic space for the elderly to live in their old age, the needs of theirs in the indoor living environment should be met both physically and psychologically to the maximum extent. From the perspective of demand satisfaction, the bedroom needs to be convenient for the independent activities of the elderly and can make them feel supported and dependent emotionally and psychologically. At the same time, the design of the indoor environment should be adjusted accordingly in the face of elderly people with different genders, ages, occupations, academic qualifications and physical conditions.

5. Conclusions

The main conclusions of this study are summarized as follows:

• (1). The overall preference for the bedroom environment and its reasons: (1) The urban elderly in China prefers lower floors (1–3 floors), south-facing rooms, room sizes of about 15–24 square meters and a simple and calm decoration style. Among them, the preference of women for lower floors (1–3 floors) is significantly greater than that of men, while the preference of men for higher floors (10–20 floors) is significantly greater than that of women. (2) About bedroom materials, the elderly prefers wood flooring, fabric sofas, cotton bedding and cotton and linen curtains. (3) The key words for the elderly bedroom color and lighting preferences are low saturation, bright, warm tones, and warm white light. This finding is supported by a Korean study, which found that the elderly would prefer a warm, comfortable and bright bedroom environment [54]. (4) The elderly prefers lamps with wide lighting range and simple environmental protection. Meanwhile, a study confirmed that in terms of furniture colors, Chinese seniors prefer “light”, “pure”, “natural”, “classical”, “organized” and “delightful” colors [55]. Therefore, indoor furnishings such as Chinese paintings, oil paintings, pointer clocks, ceramic vessels and foliage plants will be more popular among Chinese seniors. (5) Color has a significant effect on the preference for flooring materials and decorating styles of the elderly. (6) Personal attributes such as gender, physical condition and education present the most significant potential effects with indoor living environment factors.

• (2). Elderly physical environment preferences: Gender presents the most significant potential effect on elderly physical environment preferences. The specific differences between male and female groups regarding physical environment preferences are as follows.

  • (1). Regarding the choice of the most important influencing factor for indoor environmental comfort, men value the quality of light environment more than women, and the percentage of men choosing the quality of light environment is 36.4%, which is significantly higher than the percentage of women choosing the quality of light environment (19.3%). However, women pay more attention to the quality of acoustic environment than men, and the percentage of women choosing the quality of acoustic environment is 28.4%, which is significantly higher than the percentage of men choosing the quality of acoustic environment (11.4%).

  • (2). In terms of noise, women hate outdoor road traffic noise more, the percentage of women who hate outdoor road traffic noise is 58.6%, which is significantly higher than the percentage of men who hate outdoor road traffic noise (31%). Men dislike outdoor construction noise more, the percentage of men who dislike outdoor construction noise is 35.2%, which is significantly higher than the percentage of women who dislike outdoor construction noise (10.7%).

• (3). Elderly indoor environment index system: Previous studies on the indoor environment of the elderly mainly focused on a single aspect of physical measurements such as the physical environment of the bedroom, color, and materials, etc. Through the existing literature combing, combined with semi-structured interviews with the elderly, this study established a bedroom living environment preference index system for the elderly around the most concerned indoor environment issues. The index system is divided into five major parts: basic bedroom conditions, bedroom materials, bedroom colors, bedroom physical environment and other soft furnishings. Specifically, the basic bedroom situation includes five sub-indicators such as bedroom orientation and floor, bedroom materials include five sub-indicators such as floor materials and wall materials, bedroom colors include four sub-indicators such as saturation, warm and cold colors, and bedroom physical environment includes four sub-indicators such as sound environment and light environment. The indicator system is more comprehensive, and the questionnaire design is closer to reality, which enriches the research framework of indoor environment design for the elderly.

With the increasing global aging, the design of interior environment for the elderly is an urgent problem to be solved. Reasonable design of the living environment of the elderly can better facilitate the lives of the elderly, improve their self-care ability and psychological states. By studying the indoor environment preference of the elderly and its causes, the psychological and physiological needs of the elderly can be better understood. It is helpful to continue to improve the design methods of bedroom environment, which is a humane and friendly space, as well as physically and mentally healthy. Thus the quality of life and well-being of the elderly can be improved.

Due to the limited researching time and researching funding, the size of samples in this study needs to be enriched and supplemented, especially the sample of age 70+ needs to be further collected and expanded in the follow-up research work. Future research areas could be extended to regions which are not covered by this study, especially can be specific in the residential environment preferences of the elderly in different districts, ethnicities, and beliefs, to reveal richer research findings. In addition, this study mainly uses a subjective evaluation method. Future research may combine quantitative methods of measuring physical environment to do more studies, including analyzing the performance of residential buildings and the overall indoor environmental quality for elderly people. A deeper supplement and explanation to some details in this paper can be made in the future.

Author Contributions

Conceptualization, J.X. and M.L.; methodology, Q.C.; software, C.L. and Q.C.; validation, J.X., formal analysis, Q.C.; investigation, M.L.; resources, J.X.; data curation, M.L.; writing—original draft preparation, C.L., Q.C. and J.X.; writing—review and editing, X.W.; visualization, Q.C.; supervision, J.X., T.W. and M.L.; project administration, M.L.; funding acquisition, J.X. and Z.W. All authors have read and agreed to the published version of the manuscript.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are not publicly available due to restrictions regarding the privacy of the participants.

Conflicts of Interest

The author(s) declared no potential conflict of interest with respect to the research, authorship, and/or publication of this article.

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures and Table

Figure 1. Research methodology.

Figure 2. Survey area and the distribution of valid questionnaire.

Figure 3. Socio-demographic characteristics of the participants.

Figure 4. Color-related differences in indoor environment design: (a) Stack bar of cross analysis of differences according to brightness and window type; (b) Stack bar of cross analysis of brightness and lamps; (c) Stack bar of cross analysis of chroma and decoration style; (d) Stack bar of cross analysis of warm and cold hue and floor material.

Figure 5. Differences according to other factors in indoor environment design: (a) Cross analysis radar chart of mattress firmness and sofa material; (b) Cross analysis radar chart of decoration style and ceiling light type; (c) Radar chart of cross analysis of green plant type and bedding pattern.

Figure 6. Gender-related differences in basic conditions of bedrooms, sound, light and hot air: (a) Cross analysis stack bar of gender and floor; (b) Cross analysis stack bar of gender and decoration style; (c) Cross analysis stack bar of gender and factors influencing indoor environmental comfort; (d) Cross analysis stack bar of gender and noise; (e) Cross analysis stack bar of gender and heating method; (f) Cross analysis stack bar of gender and air purification method; (g) Cross analysis stack bar of gender and lamps picture.

Figure 7. Gender-related differences in bedroom decorations and materials: (a) Stack bar of cross analysis of gender and wardrobe; (b) Stack bar of cross analysis of gender and green plant selection; (c) Cross analysis stack bar of gender and bedding pattern; (d) Cross analysis stack bar of gender and door material; (e) Cross analysis stack bar of gender and floor material; (f) Cross analysis stack bar of gender and wall material; (g) Stack bar of cross analysis of gender and sofa material.

Figure 8. Age-related differences in indoor environment design: (a) Radar chart of cross analysis of age and bedding pattern; (b) Radar chart of cross analysis of age and decoration style; (c) Radar chart of cross analysis of age and window view; (d) Radar chart of cross analysis of age and wardrobe.

Figure 9. Occupation-related differences in indoor environment design: (a) Cross analysis radar chart of occupation and ceiling light type; (b) Cross analysis radar chart of occupation and decoration style; (c) Cross analysis radar chart of occupation and bedding pattern; (d) Cross analysis radar chart of occupation and green plant type.

Figure 10. Education-related differences in indoor environment design: (a) Radar chart of cross analysis of education and lamps; (b) Radar chart of cross analysis of education and wall-mounted type; (c) Radar chart of cross analysis of education and bedding patterns.

Figure 11. Differences according to physical condition in indoor environment design: (a) Cross analysis radar chart of physical condition and influencing factors of indoor comfort; (b) Radar chart of cross analysis of physical condition and heating method; (c) Radar chart of physical condition and lamps cross analysis; (d) Cross analysis radar chart of physical condition and lightness preference; (e) Radar chart of cross analysis of physical condition and sofa material preference; (f) Radar chart of cross analysis of body condition and wall material; (g) Radar chart of cross analysis of physical condition and bedding pattern.

Figure 12. Elderly care service needs of elderly groups.

Table 1

Bedroom indoor environment preferences index system of the urban elderly.

Question	Sub-Factors	Key Findings	Reference
Q7–12 Basic information of bedroom	Towards	7 styles of Romantic, Classic, Country, Modern, Natural, Casual, and Traditional were chosen for the study and the realms to apply the image preference were divided into Space	[28,29,30]
	Floor
	Area
	Decoration style
	Window scene
Q13–19 The material contained in the bedroom	Floor	Starting from the material properties, elaborated the modern furniture materials in the form of visual performance, color performance and the performance of texture, fully reflected the possibilities and endless charm of material in the modern furniture design.	[31]
	Wall
	Sofa
	Curtain
	Bed sheet
Q20–22 Color of bedroom	Saturation	Results demonstrate that preferences for warm and cool colors depend on the room type; The color scheme on one side of the wall with increased saturation seemed to improve depressive symptoms effectively.	[32,33]
	Luminosity
	Warm/cold tone
	Hue
Q23–29 Physical Environment of bedroom	Visual IEQ	The evaluation uses 16 parameters, four for each of the four areas of IEQ (IAQ, thermal, visual and acoustic IEQ).	[34,35]
	Acoustic IEQ
	Thermal IEQ
	Indoor Air Quality
Q30–38 Others	Furniture	In this study, the characteristics of the built-in closets such as structure, function and material were studied to analyze the basic changes and compared the normal closet to the built-in closet to analyze the elements in terms of environment and convenience.	[36,37]
	Furnishings

References

1. Leeson, G.W. The Growth, Ageing and urbanization of our World. J. Popul. Ageing; 2018; 11, pp. 107-115. [DOI: https://dx.doi.org/10.1007/s12062-018-9225-7]

2. Liu, H.L. Population aging in the world and China. Sci. Res. Aging; 2021; 9, pp. 1-16. (In Chinese)

3. Tu, W.J.; Zeng, X.; Liu, Q. Aging tsunami coming: The main finding from China’s seventh national population census. Aging Clin. Exp. Res.; 2021; 34, pp. 1159-1163. [DOI: https://dx.doi.org/10.1007/s40520-021-02017-4] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/34727357]

4. Lu, J.; Liu, Q. Four decades of studies on population aging in China. China Popul. Dev. Stud.; 2019; 3, pp. 24-36. [DOI: https://dx.doi.org/10.1007/s42379-019-00027-4]

5. Hong, C. Aging of population and sustainable development of the society. Popul. Econ.; 2001; 4, pp. 71-74. (In Chinese)

6. Pang, X.L.; Liu, S.L. An inquiry into the humanized design of elderly household—Take bedroom design as an example. Furnit. Inter. Decor.; 2019; 4, pp. 104-106. (In Chinese)

7. Yang, C.; Wang, W.; Li, F.; Yang, D.A. Sustainable, Interactive Elderly Healthcare System for Nursing Homes: An Interdisciplinary Design. Sustainability; 2022; 7, 4204. [DOI: https://dx.doi.org/10.3390/su14074204]

8. Kaewdok, T.; Sirisawasd, S.; Norkaew, S.; Taptagaporn, S. Application of anthropometric data for elderly-friendly home and facility design in Thailand. Int. J. Ind. Ergon.; 2020; 80, 103037. [DOI: https://dx.doi.org/10.1016/j.ergon.2020.103037]

9. Wong, J.K.W.; Leung, J.; Skitmore, M.; Buy, L. Technical requirements of age-friendly smart home technologies in high-rise residential buildings: A system intelligence analytical approach. Autom. Constr.; 2017; 73, pp. 12-19. [DOI: https://dx.doi.org/10.1016/j.autcon.2016.10.007]

10. Jingyi, M.; Shanshan, Z.; Wu, Y. The Influence of Physical Environmental Factors on Older Adults in Residential Care Facilities in Northeast China. HERD Health Environ. Res. Des. J.; 2021; 15, pp. 131-149.

11. Pinto, M.; Lanzinha, J.; Viegas, J.; Infante, C.; Freire, T. Quality of the indoor environment in elderly care centers in two cities in central Portugal: Viseu and Covilha. Int. J. Environ. Res. Public Health; 2019; 16, 3801. [DOI: https://dx.doi.org/10.3390/ijerph16203801] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/31601042]

12. Liu, D.; Ren, Z.; Wei, S.; Song, Z.; Li, P.; Chen, X. Investigations on the Winter Thermal Environment of Bedrooms in Zhongxiang: A Case Study in Rural Areas in Hot Summer and Cold Winter Region of China. Sustainability; 2019; 17, 4720. [DOI: https://dx.doi.org/10.3390/su11174720]

13. Lan, L.; Tsuzuki, K.; Liu, Y.F.; Lian, Z.W. Thermal environment and sleep quality: A review. Energy Build.; 2017; 149, pp. 101-113. [DOI: https://dx.doi.org/10.1016/j.enbuild.2017.05.043]

14. Torresin, S.; Albatici, R.; Aletta, F.; Babich, F.; Oberman, T.; Kang, J. Acoustic design criteria in naturally ventilated residential buildings: New research perspectives by applying the indoor soundscape approach. Appl. Sci.; 2019; 9, 5401. [DOI: https://dx.doi.org/10.3390/app9245401]

15. Mendes, A.; Bonassi, S.; Aguiar, L.; Pereira, C.; Neves, P.; Silva, S.; Mendes, D.; Guimarães, L.; Moroni, R.; Teixeira, J.P. Indoor air quality and thermal comfort in elderly care centers. Urban Clim.; 2015; 14, pp. 486-501. [DOI: https://dx.doi.org/10.1016/j.uclim.2014.07.005]

16. Ossokina, I.V.; Arentze, T.A.; van Gameren, D.; van den Heuvel, D. Best living concepts for elderly homeowners: Combining a stated choice experiment with architectural design. J. Hous. Built Environ.; 2019; 35, pp. 847-865. [DOI: https://dx.doi.org/10.1007/s10901-019-09716-5]

17. Bamzar, R. Assessing the quality of the indoor environment of senior housing for a better mobility: A Swedish case study. J. Hous. Built Environ.; 2019; 34, pp. 23-60. [DOI: https://dx.doi.org/10.1007/s10901-018-9623-4]

18. Dake, W.; Xi, L. Measuring the spatial quality of bedrooms in nursing homes with visual environmental perfmance. Front. Archit. Res.; 2021; 10, pp. 332-350.

19. Yan, Y.; Lan, L.; Zhang, H.; Sun, Y.; Fan, X.; Wyon, D.P.; Wargocki, P. Association of bedroom environment with the sleep quality of elderly subjects in summer: A field measurement in Shanghai, China. Build. Environ.; 2022; 208, 108572. [DOI: https://dx.doi.org/10.1016/j.buildenv.2021.108572]

20. Liu, S.L.; Gao, J.W. Research on furniture design for the aged based on intelligent System—Take bedroom furniture as an example. Furniture; 2018; 39, pp. 49-52. (In Chinese)

21. William, O. New Philosophies of Social Science: Realism, Hermeneutics, and Critical Theory; Springer: Berlin/Heidelberg, Germany, 1987; pp. 10-130.

22. Bai, C.; Lei, X. New trends in population aging and challenges for China’s sustainable development. China Econ. J.; 2019; 13, pp. 3-23. [DOI: https://dx.doi.org/10.1080/17538963.2019.1700608]

23. Hongwei, Z.; Wei, H. The application of environment psychology theory in landscape design of residential area for the elderly. Archit. Cult.; 2020; 6, pp. 206-207.

24. Liang, Y. An analysis of family pension in my country under the background of aging—Based on the comparison of the origin of different pension cultures and pension methods in China and the West. Times Financ.; 2012; 12, 259.(In Chinese)

25. Weiss, D.; Zhang, X. Multiple sources of aging attitudes: Perceptions of age groups and generations from adolescence to old age across China, Germany, and the United States. J. Cross-Cult. Psychol.; 2020; 51, pp. 407-423. [DOI: https://dx.doi.org/10.1177/0022022120925904]

26. Fan, R. Confucian Filial Piety and Long-Term Care for Aged Parents; HEC forum Springer Nature: Berlin, Germany, 2006; 1.

27. Jin, Y.N. The application of questionnaire designed by “Questionnaire Star” in the management of modern educational technology and equipment in aging scientific research. Chin. Mod. Educ. Equip.; 2015; 2, pp. 4-7. (In Chinese)

28. Chen, J.; Li, D.J.; Zhang, Y.; Wang, K. Interior Design Principles; Shanghai People’s Fine Arts Publishing House: Shanghai, China, 2010; pp. 100-120. (In Chinese)

29. Seo, M.W.; Jeong, Y.N. Senior Citizens’ Image Preference for Interior Design Styles. Korean Inst. Inter. Des. J.; 2012; 21, pp. 109-120.

30. Xu, S. Visual Performance of Materials in the Modern Furniture. Packag. Eng.; 2010; 31, pp. 23-25.

31. John, P. Color in Interior Design; McGraw-Hill Professional: New York, NY, USA, 1997; pp. 20-150.

32. Torres, A.; Serra, J.; Llopis, J.; Delcampo, A. Color preference cool versus warm in nursing homes depends on the expected activity for interior spaces. Front. Archit. Res.; 2020; 9, pp. 739-750. [DOI: https://dx.doi.org/10.1016/j.foar.2020.06.002]

33. Jung, C.L.; Mahmoud, N.S.A.; El Samanoudy, G.; Al Qassimi, N. Evaluating the Color Preferences for Elderly Depression in the United Arab Emirates. Buildings; 2022; 12, 234. [DOI: https://dx.doi.org/10.3390/buildings12020234]

34. Larsen, T.S.; Rohde, L.; Jønsson, K.T. CompassTIEQ-Compuation of potential indoor environmental quality. Build. Environ.; 2020; 172, 106707. [DOI: https://dx.doi.org/10.1016/j.buildenv.2020.106707]

35. Ngarambe, J.; Yun, G.Y.; Lee, K.; Hwang, Y. Effects of Changing Air Temperature at Different Sleep Stages on the Subjective Evaluation of Sleep Quality. Sustainability; 2019; 5, 1417. [DOI: https://dx.doi.org/10.3390/su11051417]

36. Smith, S. Interior designer to the core (William Morgan’s ‘Interior Design & Decoration’). Archit. Rec.; 2007; 195, 23.

37. Lee, S.Y. A Comparative Study on the Residential Furniture Design Preference according to Consumers Characteristics. J. Korea Contents Assoc.; 2008; 8, pp. 146-155. [DOI: https://dx.doi.org/10.5392/JKCA.2008.8.3.146]

38. Zheng, T.G.; Zhao, Y. Spatio-temporal evolution and cause analysis of sex ratio of elderly population in China. J. Northwest Norm. Univ. (Nat. Sci. Ed.); 2019; 55, pp. 95-101. (In Chinese)

39. Xu, Y. Ninety percent of the elderly long for spiritual care. Evening Sunny; 2013; 11, 61.(In Chinese)

40. Zhu, Y.; Liu, S. Analysis on the characteristics of old-age care for the elderly in China’s urban Kochi—Also on the enlightenment of the second demographic dividend. Chongqing Soc. Sci.; 2019; 9, pp. 26-37. (In Chinese)

41. Tao, T.; Xu, H.Y.; Zhao, Y.N. Design & Practice of Bedroom Furniture Suitable for the Aged Based on Physiological Characteristics of the Elderly. China For. Prod. Ind.; 2018; 45, pp. 47-49. (In Chinese)

42. Nyrud, A.Q.; Bringslimark, T. Is Interior Wood use Psychologically Beneficial? A Review of Psychological Responses toward Wood. Wood Fiber Sci.; 2010; 42, pp. 202-218.

43. Perera, S.; Eisen, R.; Bhatt, M.; Bhatnagar, N.; Samaan, Z. Light therapy for nonseasonal depression: Systematic review and meta-analysis. BJPsych Open; 2016; 2, pp. 116-126. [DOI: https://dx.doi.org/10.1192/bjpo.bp.115.001610]

44. Zhao, X.; Ma, J.; Wu, S.; Chi, I.; Bai, Z. Light Therapy for Older Patients with non-seasonal depression: A Systematic Review and Meta-analysis. J. Affect. Disord.; 2018; 232, 291. [DOI: https://dx.doi.org/10.1016/j.jad.2018.02.041]

45. Windle, G.; Woods, R.T. Variations in subjective wellbeing: The mediating role of a psychological resource. Ageing Soc.; 2004; 24, pp. 583-602. [DOI: https://dx.doi.org/10.1017/S0144686X04002107]

46. Neeraja, T.; Fareq, R.U. Determinants of Bedroom Design in Elderly Housing. Curr. J. Appl. Sci. Technol.; 2020; 39, pp. 162-168.

47. Booranrom, Y.; Watanapa, B.; Mongkolnam, P. Smart bedroom for elderly using Kinect. Proceedings of the 2014 International Computer Science and Engineering Conference (ICSEC), IEEE; Khon Kaen, Thailand, 30 July–1 August 2014; pp. 427-432.

48. Zhao, L.R.; Zhu, J. Elderly bedroom furniture suitable old design analysis. Furniture; 2015; 36, pp. 76–81+85. (In Chinese)

49. Fu, Y.; Wu, Y.; Gao, W.; Hui, R. The Effect of Daylight Illumination in Nursing Buildings on Reading Comfort of Elderly Persons. Buildings; 2022; 12, 214. [DOI: https://dx.doi.org/10.3390/buildings12020214]

50. Gu, C.; Zeng, J. Research on the Design of the Elderly Wardrobe Based on Ergonomics. IOP Conf. Ser. Mater. Sci. Eng.; 2019; 573, 012058. [DOI: https://dx.doi.org/10.1088/1757-899X/573/1/012058]

51. Dzierzewski, J.M.; Buman, M.P.; Giacobbi, P.R.; Roberts, B.L.; Aiken-Morgan, A.T.; Marsiske, M. Exercise and sleep in community-dwelling older adults: Evidence for a reciprocal relationship. J. Sleep. Res.; 2014; 23, pp. 61-68. [DOI: https://dx.doi.org/10.1111/jsr.12078] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/23980920]

52. White, M.; Ancoli-Israel, S.; Wilson, R. Senior living environments: Evidence-based lighting design strategies. Health Environ. Res. Des. J.; 2013; 7, pp. 60-78. [DOI: https://dx.doi.org/10.1177/193758671300700106]

53. Scheidt, R.J.; Norris, B.C. Place therapies for older adults: Conceptual and interventive approaches. Int. J. Aging Hum. Dev.; 1999; 48, pp. 1-15. [DOI: https://dx.doi.org/10.2190/KWBT-8PYT-LYA6-1WPT]

54. Oh, C.-K. Preference Difference for Interior Style of Residential Space Depending on the Elderly’ Characteristics and Cognitive Ages. Korean Inst. Inter. Des. J.; 2016; 25, pp. 56-64. [DOI: https://dx.doi.org/10.14774/JKIID.2016.25.1.056]

55. Gao, J.; Jin, R.C. A Study on the Color Preference for Interior Parts of Bedrooms in Geriatric Hospitals. Korean Inst. Inter. Des. J.; 2018; 27, pp. 135-143. [DOI: https://dx.doi.org/10.14774/JKIID.2018.27.6.135]