1. INTRODUCTION
After decades of great development, the construction of Chinese cities has made great achievements. At the same time, the problem of improving the quality of urban space has become increasingly prominent. In particular, the problem of insufficient urban space has become a bottleneck in improving urban quality.
According to statistics, there are over 300,000 of workers living in the basement of Beijing, most of whom are migrant workers who are from cities outside Beijing. They are called “the rat tribe” by the media because they live in the basement with low rents, poor conditions, no sunlight all day, and lack of supporting facilities.
Most of these basements were an important part of the Mao’s Cold War defense strategy 40 years ago. In the 1980s, when the country’s economy was liberalized, some of the basements were handed over into shops or offices. The majority were converted into residential units for rent.
For such underground residences, Beijing announced that by the end of 2012, living in these basements would no longer be legal, but this deadline was later extended to 2017. However, in August 2019, Beijing again issued a policy to make detailed requirements for the use of underground space. They are no longer illegal, but made detailed rules: the per capita living area must not be less than 5 square meters, and the number of people in each room must not exceed 2 people etc.
It can be seen from this above that “the rat tribe” is a very special group of people in a marginalized situation. Furthermore, only banning the basement and taking tough measures to drive away them will not improve the living environment of the vulnerable groups in the city, nor will it solve their housing problems.
Therefore, my hypothesis is that by analyzing the rat tribe’s professional status, geographic spatial distribution, room types, and local government policies, the article will explain the living conditions of this group in the underground space. Secondly, by analyzing the problems of the existing affordable housing system, the article will claim that “the rat tribe” will continue to live in the basement for a period of time and they are really an important force in urban life. Therefore, we can argue that the basement for this Huge low-income group in Beijing should not be banned, but a way to improve their living environment should be explored.
2. GOALS
1). Through research and investigation of relevant literature, understand the distribution structure and living situation of such groups of “the rat tribe”, and promote city managers and designers to understand and pay attention to vulnerable groups.
2). With the current “the rat tribe” housing as the research object, from the perspective of urban planning, explore the theory and design methods of underground space development, and promote the harmonious development of society.
3. RESEARCH BACKGROUND
According to data from the Beijing Municipal Bureau of Statistics, in the first half of 2018, the level of rented housing in Beijing increased by 3.1% compared with the same period last year, while the rent in some areas increased by 10.5%. At this point, Beijing housing rents have continued to rise for 48 months. Rising rents are forcing more and more new workers into the city to move to live underground.[1]
Beijing’s underground space can be divided into three categories:1) civil defense engineering. (Since dugout works are built for safe shelter during wartime, there are no ventilation and light-transmitting facilities, and living and storage of debris are not allowed);2) ordinary basement and basement. (These basements are underground storage spaces supporting residential buildings); 3) semi-underground basements (The underground space has ventilation and light-transmitting facilities, as well as conditions for keeping warm and burning, and can be used for living). Due to their low rents, the former two types have become the preferred living type for the Rat tribe.
The use of these underground spaces has also undergone a transition from encouragement to governance to restricted use.
Since the 1980s, Beijing has built a large number of underground civil dugout projects in combination with ground buildings, which are used for wartime air defense needs and also take into account the needs of economic construction and people’s lives in peacetime. However, the conditions of many underground civil dugout projects are gradually deteriorating due to lack of special fund maintenance and management. (Anagnost A, 1995.p.22)
In order to change the dirty and messy situation of underground civil air defense, in the 1990s, government departments encouraged the use of civil dugout works and charged a certain fee. At that time, the tenants started to use underground defense projects to open underground hotels, but the number was not large.
At the end of the 1990s, with the influx of large numbers of migrate people, underground space was used more adequately. By 2004, Beijing had reached a peak in the lease of civil dugout projects, which has been increasing year by year.
In November 2004, Beijing issued regulations requiring underground space to be used in hotels, dormitories, and other dwelling places, and must abide by laws and regulations such as public security, fire protection, and sanitation. It is not allowed to change the space structure without authorization. The per capita use area in the room shall not be less than 4 square meters.
In January 2005, the policy was officially implemented, but the chaotic management of underground space has not completely changed. As the population of underground residents continues to increase, the contradictions between underground residents and community residents have become increasingly prominent, so the policies of the local government have changed again. Beijing announced that living in these basements would no longer be legal by the end of 2012, but this deadline was later extended to 2017. In August 2019, Beijing again issued a policy to make detailed requirements for the use of underground space. They are no longer illegal, and it was made detailed rules: the per capita living area must not be less than 5 square meters, and the number of people in each room must not exceed 2 people; No bunk beds, etc. are allowed in the room.
4.1 POPULATION CHARACTERISTICS OF “THE RATS TRIBE”
According to statistics, there were 7,782 dwelling basements in the central urban area of Beijing in 2011, and a total of 344,353 people lived underground. (Youqin Huang and Chengdong Yi,2015. p. 2949)
According to Chinese Professor Li Junfu’s survey (the study is in the form of a questionnaire, 550 questionnaires were sent out, 530 questionnaires were returned, and 511 valid questionnaires), more than half of “the rat tribe” who chose the basement as living quarters were business service employees: Groups refer to non-professional, labor-intensive, and manual workers in the business and service industries. In their survey, such personnel accounted for the highest proportion, reaching 50.7%. Such personnel mainly include those engaged in catering, environmental sanitation, security, entertainment, property, housekeeping and other tasks. Among them, 80% are engaged in catering, sanitation and housekeeping. (Li Junfu, Qi Dan, Chai Hongxia,2014. p.103)
Secondly, the industrial worker class accounts for a relatively large proportion, accounting for 12.2% of “the rat tribe”. This group refers to production workers, construction workers and related personnel who are engaged in manual labor and semi-physical labor in the secondary industry. It mainly includes manufacturing workers and construction workers. ( (Li Junfu, Qi Dan, Chai Hongxia,2014. p.104))
Moreover, the unemployed and semi-unemployed class accounted for 9.2%. Other strata such as the individual industrial and commercial household stratum, the clerk stratum and the professional and technical staff stratum have a smaller proportion.
It can be seen that the basement living group is not a single class, but a complex group of people with different occupations and identities. From the perspective of employment characteristics, it is mainly composed of lots of professional classes. (Li Junfu, Qi Dan, Chai Hongxia,2014. p.104)
In addition, this group is younger in age structure. According to the new age classification standard proposed by the United Nations World Health Organization in 2001, the life of a tradesman is divided into five stages: young people beyond 44 years old; 45-59 years old as middle-aged people; 60-74 years old as younger elderly; 75-89 years old is the elderly; 90 years old and above are longevity elderly. Among the groups living in the basement, 89% of young people under the age of 44 accounted for 89%, of which 18% followed by 2.4%. It can be seen that a large number of employees in the basement dwelling groups are young, and all strata show a young age structure. (Li Junfu, Qi Dan, Chai Hongxia,2014. p.106)
Finally, this class generally has lower incomes. Wages and income are between RMB 2211.54 and RMB 3305.55, which is equivalent to 46.4% -69.4% of Beijing’s average salary of RMB 4,762 in 2011. (Li Junfu, Qi Dan, Chai Hongxia,2014. p.107) Therefore, this group has a small income gap and a small economic difference.
4.2 DISTRIBUTION SPACE
These basements for rent are mainly distributed in the central urban area, mainly in Chaoyang, Haidian, Fengtai, Xicheng and Dongcheng. Among them, Chaoyang, Haidian, and Fengtai districts outside the old city area have a larger number of distributions, while the number in the old city is less. (Shang Qian, Zhu Wenyi, 2015.p.103)

Figure1: Schematic diagram of the spatial distribution of contemporary Beijing basements[2]
In recent years, with the large increase of migrant workers in Beijing, more and more people are living in basements. Residential buildings built in the 1990s have become the main carrier of basement renters. Some of these basements are on the first basement level, and some are on the second basement level. Large residential communities often have large areas of civil air defense basements, which have more space to use than small residential areas. As a result, these “rat tribe” are important locations for large residential communities. (Shang Qian, Zhu Wenyi, 2015.p.104)
The distribution of “the rat tribe” is closely related to the surrounding city functions. They are usually close to commercial areas or commercial centers, because these areas have a large number of tertiary industries such as accommodation and catering, wholesale and retail, and residential services. These industries are precisely those in which migrant workers are more involved. Living in this area, on the one hand, can save a lot of travel time for migrant workers to and from work. On the other hand, the urban business district has a large demand for tertiary industry workers, which makes it easier for them to find job opportunities.
There are convenient transportation stations around these basement settlements. For example, around the basement always have 2-3 subway station within 1km of the residence, and the distance between individual stations and the residence is within 500m suitable for walking. (Shang Qian, Zhu Wenyi, 2015.p.104)
Therefore, the basement finds a balance between the work and life of migrant workers: the commercial area around the city center provides a low-cost and convenient residence. The average monthly rent of a small basement is only 200-400 RMB (26-53euros), which is one third of the rent of the house on the ground in the same location of the same size. More importantly, it is located in the center of convenient life.

Figure2: basement interior environment

Figure3: basement interior environment

Figure4: basement interior environment[3]
4.3. ROOM TYPES
According to the number of occupants, the basement can be divided into three types: single living, family living and group play.
Among them, the size of the space for single living is very small. The area of the basement for single living is only 4-8 square meters. The layout of the space is relatively simple. A bed and a small table are standard equipment for this type of living room. Because of the small size of many bedrooms, there is almost no room for extra furniture, except for a bed. Therefore, the corners of the living room are also used: water pipes and ventilation pipes become shelves for storing items, pulling some ropes for hanging clothes and so on. (Shang Qian, Zhu Wenyi, 2015.p.104)
The size of the family living space is still small, usually 6-10 square meters for 2-3 people. Because it is the cooking space of the family living and the storage space of related videos and appliances, it becomes an essential part of the living room. (Shang Qian, Zhu Wenyi, 2015.p.104)
The size of the group living space is relatively large, with an area of about 15-25 square meters, and usually 3-8 people. This type of room is generally a staff dormitory in a unit, with single beds and simple wardrobes as standard. Some units with better conditions will set up separate underground activities for the dormitory, they can watch TV, and some will be equipped with heating and air conditioning. (Shang Qian, Zhu Wenyi, 2015.p.104)
overall, as a form of living, the basement room is simple and poorly furnished, which is far below normal living standards. Most of them are lack of fresh air, insufficient sunlight and lighting while those basements have fire prevention problems, sound insulation and poor earthquake resistance.

Figure5: Entrance to a basement in Beijing

Figure6: A corridor of a basement[4]
4.4 FROM PUBLIC HOUSING TO COMMERCIAL HOUSING
The basement of Beijing is a product of the Mao Zedong era. During that period, China was under the public real estate system. In December 1948, the “Decision on the Issue of Public Real Estate in the City” was promulgated. After the founding of New China, urban housing was cleaned and confiscated. A public housing management committee is set up in the city to uniformly manage and distribute all common houses in the city. (He Yong, Xie Xiaoping, et al.,2017. p. 4)
After 1978, a socialist market economic system was established. Various types of housing system reforms have emerged one after another, but in the early days of reform, the ideology of housing as welfare goods still prevailed. (He Yong, Xie Xiaoping, et al.,2017. p.9)
From 1992 to 1997, the transition period for the welfare housing distribution system to the full marketization of housing. Driven by the reform and opening up policy, real estate prices have been liberalized, and the government has begun to implement various macro-control policies to promote the development of housing commercialization and housing construction. ( He Yong, Xie Xiaoping, et al.,2017. p.19)
The period from 1998 to 2003 was a period of comprehensive transition from the welfare housing distribution system to the commercialization of housing. China’s housing supply mechanism has become market-oriented. Since then, the sale of public residential housing to employees has been implemented throughout the country. The government aim to build a multi-level housing supply system with affordable housing as the main body, low-rent housing and ordinary commercial housing as supplements should be established in the city. ( He Yong, Xie Xiaoping, et al.,2017. p.22)
Since 2004, real estate investment has grown rapidly, and the prices of commercial housing have risen sharply. Although the government clearly proposed to reduce the excessively high housing prices, the prices of commercial housing still rose all the way. (He Yong, Xie Xiaoping, et al.,2017. p.25)
The rise in house prices is even more pronounced in first-tier cities. Therefore, in first-tier cities such as Beijing and Shanghai, many low- and middle-income people face housing difficulties.
4.5. AFFORDABLE HOUSING
Obviously, “the rat tribe” has housing problems. The housing problem in the broad sense refers to the lack of living supply and insufficiency, which makes it difficult to meet the housing needs of some members of society. The housing problem in the narrow sense mainly refers to the housing security problem of low- and middle-income groups. The core is the contradiction between the ability of middle- and low-income people to get rich in housing consumption and housing demand. In other words, the contradiction between high house prices and low residents’ income. Therefore, the problem of housing difficulties for low- and middle-income populations requires the state to provide corresponding housing security.
In 1998, China for the first time promulgated relevant systems for building social security housing. After years of development, a variety of affordable housing models have been formed: such as affordable housing, low-rent housing, and commodity housing with limited prices. However, there are still problems of lagging housing construction and narrow coverage. As a result, a group of “sandwich groups” that did not meet the conditions for renting low-cost housing and could not afford affordable housing and commercial housing appeared. At the same time, with the development of urbanization, the living needs of a large number of migrant workers are increasing, so public rental housing has emerged as the times require. (KAHN, MATTHEW E., and SIQI ZHENG,2016. P. 370)
Public rental housing is one of the state’s affordable housing. Public rental housing refers to the rental housing provided by the government or a public agency commissioned by the government and offered to households with income from farmland at a price lower than the market rent. The government provides rental subsidies to rented families in accordance with the standard, and the property rights of the housing belong to the government or public institutions. On June 12, 2010, the Ministry of Housing and Urban-Rural Development and other departments jointly formulated the “Guiding Opinions on Accelerating the Development of Public Rental Housing” for the first time.
Because this type of public rental housing has limited space and rent regulars, and it is only available for specific groups: such as college students who have just graduated, vulnerable groups in cities, and migrant workers. This policy is good for “the rat tribe.” Furthermore, if public rental housing can be promoted on a large scale, people’s eagerness to buy a house can be reduced, and housing price growth can be suppressed indirectly. This mode of housing supply is suitable for the initial employment, there is no savings, and groups with housing difficulties at this stage.
However, public rental housing is the latest housing supply model in China at this stage, and it also has some shortcomings.
First, compared with actual demand, the coverage of public rental housing is relatively small. At present, the housing security object in most areas of China is limited to urban low-income families. In other words, to enjoy public rental housing, they must have an urban household registration. Thence, if migrate people want to live in public rental housing, they need to solve the household registration problem firstly. For “the rat tribe” group, which is mostly migrant workers, their household registration is basically outside Beijing, and there is no way to enjoy the treatment of public rental housing. Moreover, the construction scale of affordable housing currently accounts for less than 10% of the scale of housing construction in the whole society, and the covered population accounts for less than 8% of the total urban population. (KAHN, MATTHEW E., and SIQI ZHENG,2016. p. 372)
Secondly, the construction link is imperfect. At present, most of the demand for affordable housing is in urban areas, and the government has built many affordable housing in the suburbs due to land cost, planning and other reasons. Suburban traffic is inconvenient and supporting facilities are incomplete. If things go on like this, “poor communities” will be formed around towns and cities, causing social problems.
Thirdly, rent standards cannot be unified. The purpose of public rental housing is to expand the scope of housing security. If the rent is high, the housing target cannot afford it. If the rent is low, the public rental housing lacks maintenance funds and management costs. Therefore, we need to introduce some supporting detailed measures to truly solve the housing problem of low-income people.
5. CONCLUSION
1). “The rat tribe” is a long-standing phenomenon in the process of urbanization. They have received little attention in the past. The basement they lived in was poor and poorly furnished, well below normal living standards. However, the basement living rent is low, which can meet the actual needs of a considerable number of migrant workers in Beijing. Therefore, in a short time, Basement residence is an indispensable form for the operation of big cities like Beijing. On the one hand, he can meet the living requirements of service business workers; on the other hand, there are a large number of idle underground spaces in the city. For “the rat tribe”, it is necessary to formulate corresponding design and management specifications to ensure the quality of life of migrant workers.
2) The main problem facing contemporary human society is to survive and develop in a peaceful environment. However, in terms of living space, the increasing population has insufficient space capacity on the earth’s land surface. In terms of urban development, the problems of insufficient living space and the shortage of urban land resources are increasingly prominent. Therefore, if the problem of underground space living can be solved scientifically and a certain scale can be formed in the development of underground space, it will be of great significance to save land resources.
3) The construction of affordable housing has not kept up with the pace of housing demand. Rising housing prices have made it impossible to meet the housing needs of the majority of low- and middle-income groups. The government’s pursuit of economic efficiency will hinder the implementation of the affordable housing system. The fairness and justice of the government will promote the improvement of the affordable housing system. Increased government housing security spending can increase residents’ satisfaction with affordable housing policies.
Wenting Xu, 2020
CITIES AND URBANISM IN ASIA PACIFIC_UPF
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[1] China News Network, 2018. Some housing rents in Beijing rise after the year http://www.xinhuanet.com/local/2018-04/19/c_1122705956.htm (access 28March, 2020)
[2] Figure 1 is from Shang Qian, Zhu Wenyi. 2015.A study on “Rat-dwelling” Rooms in Beijing. City design. (2015(01))
[3] Figures 2,3,4 ,5are from: China Daily “Beijing” Rat Race “Life Status”. (March.,2015). Photographers: Sim Chi Yin, Ian Johnson. http://www.chinadaily.com.cn/interface/toutiao/1139301/2015-3-17/cd_19831546.html (access 28March,2020)
[4] Figure 6 is from The fierce regulation and control of Beijing’s basement has just become a “new favorite” (24thOCTOBER,2016) http://news.sohu.com/20161024/n471108321.shtml