Domestic Environmental Experience Design

The term ‘domestic environmental experience’ was defined as users’ experiences of cognitive perceptions and physical responses to their domestic built environments. Domestic environments can be enriched through the implementation of environmental experience design (EXD) by combining users’ environmental, spatial and contextual factors that may accommodate occupants’ needs and demands as well as their health and wellbeing. Here, an EXD theoretical concept has been developed based on the ‘User-Centred Design’ thematical framework.


Introduction
Generally, people spend most of their time in indoor environments . In the domestic setting, occupants' living experiences are diverse, and they have numerous preferences related to their spatial needs and The key aim of this study is to explore an architectural design concept for the domestic living environment through the occupants' household experiences that may influence their mental health and wellbeing.

Context of the Study
In order to explore the stipulation of this particular study, as well as to enlighten the concept to the reader with the limitation or gap of which the motivation for this study depends, it is important to provide a study contextualisation in which it explains. In this study, middle-income families are considered as the focus group locally and globally and their domestic living environment particularly in Dhaka, Bangladesh, has been described as an example of a developing country's urban housing scenario to explore the concept of domestic environmental experiences that may affect occupants' health and wellbeing.

World Income Group Projections
Since 2000, the number of middle-income people in the world's urban areas has been steadily increasing

Income Group Scenarios of Bangladesh as an Example
Bangladesh is the fastest urbanising emerging country in the world. In Bangladesh, young generations are the key contributor to the country's economy and significantly influence the country's socioeconomic growth . Around 47.6 million (approximately 29 percent) of the total population has been identified as young generations of Bangladesh, with an age limit between 18 and 35 years old . Millions of people from this young community in Bangladesh belong to middle-income families and they are the core economic contributor to the country . At present, these income groups have become the most trained and educated part of the country's population .

Health and Wellbeing Problems in Bangladesh
According to the World Health Organization (WHO), a larger portion of the young generation in   According to the housing survey and BRAC reports in 2017, about 70-80 percent of middle-income [16] [ families in Dhaka metropolitan areas are renters . In Dhaka, house prices are increasing disproportionately compared to the housing needs of middle-income families . Therefore, almost 70-78 percent of these middle-income families, particularly lower-middle and middle-income groups, cannot afford their own houses or apartments in the current market price of housing in Dhaka City, Bangladesh ( Figure 2) .

Overview of Housing Issues in Dhaka
The housing sector of Dhaka City is mainly reliant on public and private providers . The public sectors supply approximately 7-10 percent of the total housing that is predominantly to the government's public servants. The rest of the housing sector relies on the private sectors where about 70 percent of private real estate developers are targeting the higher-and upper-middle-income groups that include houses and apartments with a size greater than 1000 sqft (92 sqm) . It is also estimated that there is a shortage of about 0.5 million housing units by 2020, whereas only 25,000 housing units are supplied yearly by private sectors. However, the supply of housing is insufficient so far, and it is expected that by 2035, the backlog of private sector housing units will be approximately 0.7 million .
Consequently, it is increasingly becoming difficult for middle-(i.e., lower-middle and middle-middle) income families to buy or afford decent residential space (e.g., apartment or dwelling unit) within the apartment size greater than 1000 sqft or more in comparison of their income level in an urban area such as Dhaka, especially when only single-earning members support families ( Figure 4) .  .
To address the situation, housing sectors (both public and private) are now changing their target group from higher and upper-middle income to lower-middle and middle-middle income groups by developing high-density small-sized flats or apartments ( Figure 5) .  Dhaka City residents suffer from numerous physical and mental health problems . These problems are prominent among middle-income families, mainly those who are living in high-density urban housing.
Particularly, these families have little capability to change or modify their existing domestic living circumstances because of their socioeconomic boundaries . Such limited architectural design considerations for the high-density urban housing may not be sufficient to address occupants' wellbeing problems in the local context .

Study Rationale for Local and Global Context
Due

Built Environment and Human Responses
The built environment has diverse terms and ideologies and most spatial design elements formed by

Home as Domestic Environment and Conceptual Meaningfulness
The domestic setting has both indoor and outdoor environmental factors that reflect occupants' needs and demands . The domestic setting protects occupants from unwanted bad weather, while occupants' psychological comfort or satisfaction needs to be well maintained to enhance their wellbeing .
The term "domestic environment" refers to the space where occupants live and correlate with sociocultural and environmental factors that may affect their health and wellbeing . Cooper (1974) indicated that home is the mother of the entire environment of security and love . Mallett (2004) addressed the notion of home as a dwelling place of interaction between humans, places and things; considering sociocultural aspects. It can be associated with occupants' numerous feelings, moods and emotions . Stokols (1972)

Domestic Environment and Occupants' Psychological Responses
Home has multilayered characteristics integrating memories, desires, intimacy, privacy, identity, function [37] [ and even language . The domestic environments reflect occupants' behaviours because of their numerous physical, psychological and social contextual experiences (Figure 9). The domestic environment has various purposes and meaningfulness related to occupants' spatial and environmental factors. Generally, a domestic environment is the combination of three types of spatial zones (e.g., public, Occupants may prefer to control these issues according to their preferences. The outside environmental relationship through openings, window, balcony and toilet attachment may create a spiritual connection with occupants' minds . Domestic satisfaction or comfort depends on the occupants' needs and preferences closely related to their spatial and environmental factors in living environments .

Defining Domestic Environmental Experience
Several psychological and phenomenological studies have been conducted to define the meaning of the domestic environment . According to Pallasmaa, the phenomenology of the domestic environment (as home) is not just an architectural effort. It has an aesthetic view considering physical, psychological and sociocultural phenomena. Pallasmaa believes that the domestic environment has multilayered characteristics integrating memories, desires, intimacy, privacy, identity, function and even language . Continuing the exploration, the domestic environment becomes an essential feature of 'selfidentification' for the middle class where privacy, comfort and domesticity are the occupants' core achievements . In general terms, each element of the domestic environment has the [50] [ meditative power of occupants' emotions and feelings . Considering several studies, the term 'domestic environmental experience' has been defined as "…user experiences of cognitive perceptions and physical responses to their domestic built environment…" with a diversity of occupants' daily household activities . In short, domestic environmental experience connects occupants' physical, psychological and social needs and demands that are correlated with different factors of the built environment ( Figure 10) .

Toward Domestic 'Environmental Experience Design'
Today's architectural design approaches or practices create a gap between users' spatial, environmental and psychological needs and demands . According to Lawrence (1990), a study gap exists between two current theories, namely the theory of 'environmental deterministic' and 'social constructivism' .
The environmental deterministic theory defines the physical environment's impacts on human behavior.
The scope of explanation about users' sociocultural contexts is limited in this theory. On the other hand, the social constructivism theory describes users' social and cultural perceptions where consideration of built environmental effects is limited . The position of 'environmental experience design (EXD)' between the two spectra that derive from the user-centred theory and address the user's social, cultural, spatial and environmental aspects ( Figure 11) . Figure 11. Research gap and future experience design direction. Modified from Source: . Kling (1977) coined the term 'user-centred design (UCD)', a person-centric philosophical design approach that focused on the human cognitive interaction with objects, products or things . The concept of UCD became widely popular as 'user experience (UX) design' due to the publication of a book entitled 'User- [4] [

Domestic Environmental Experience Design Hypothetical Construct
An EXD theoretical concept has been developed based on this 'user-centred design' thematical framework ( Figure 13) . In this theoretical concept, the user experience's core aspects are summarised in three separate components: spatial design factors, environmental factors and user contextual experiences.
Without understanding occupants' experiences, it may be difficult to identify architectural environmental design solutions to enhance occupants' mental health and wellbeing or satisfaction in their living environment not only in locally e.g., Dhaka, Bangladesh but also globally. occupants' preferences and restrictions as well as their needs and demands. Therefore, exploring the notion of domestic environmental experience design will be the future research direction in the architectural design domain to enhance occupants' health and wellbeing in high-density urban housing locally (e.g., Bangladesh) and globally.