Study of Plans to Ensure the Sustainability of Urban Farming in Apartment Complexes

Abstract

Urban farming carries environmental, economic, and social benefits. However, it is challenging to secure agricultural land in Republic of Korean cities because of on cost constraints, resulting in low levels of engagement in urban farming. In this study, we attempted to explore the novel possibility of targeting apartments as urban farming sites. Despite the high ratio of apartments to other types of homes in Korean cities, there have been limited studies examining urban farming in apartment complexes. We derived indicators of urban farming initiation and ranked their importance. Based on the results, we propose policy directions for facilitating urban farming in apartments. Indicators were selected in three steps. First, initial indicators were obtained through reviews of urban farming theories, a literature review, and analysis of media articles. Second, the indicators were preliminarily categorized by type. Third, in-depth interviews and pilot surveys were conducted to select and stratify the final indicators. The importance of the indicators was analyzed using the analytic hierarchy process. Per our results, “public funding,” and “technical and management support” are the most important factors for facilitating urban farming in apartment complexes. These findings indicate four policy directions and important implications based on their expected effects.

1. Introduction

1.1. Research Background

Numerous studies have highlighted the importance and benefits of urban farming. These studies can be largely categorized into three types. First, studies from the environmental perspective have focused on the reduction of particulate matter through an increase in urban green spaces [1], carbon reduction [1], responses to climate-change impacts [1], and control of environmental pollution driven by a reduction in the size of the distribution network for agricultural products [2]. Second, studies from the economic perspective have delved into job creation [3,4,5,6,7], energy savings due to the reduction in the size of distribution networks for agricultural products [2,4,7,8], and food self-sufficiency [1,7]. Third, studies from the social perspective have focused on agricultural education for youth [6], facilitation of local communities [2], recreational activities [6,7,9], sustainable agriculture [8,10], and diversity of urban landscapes [1,6,7,9].

The urbanization rate in Korea increased from 39% in 1960 to 80% in 2000 and 82% in 2023, and it is expected to continue to rise in the future [11]. With increasing urbanization, the percentage of the population involved in farming has gradually dropped to 4.2% as of 2022 [12], indicating that people have fewer opportunities to engage in agricultural activities both directly and indirectly.

Accordingly, Korea has introduced the concept of urban farming to solve agricultural issues driven by rapid urbanization and to integrate the advantages of urban farming into cities. For example, the Korean government enacted the “Act on Development and Support of Urban Agriculture” in 2011 to facilitate urban farming [13]. Various metropolitan cities, including Seoul, are striving to encourage widespread urban farming through diverse programs and training.

1.2. Necessity and Purpose of Our Research

Despite the advantages of urban farming and intensive efforts by the government to promote it, farmland in urban areas has been steadily declining [14]. Additionally, high land prices are preventing the purchase of land to facilitate urban farming. Although there are urban-farming programs supported by public organizations, they focus on school or farm/park programs such as weekend farms, vegetable-garden sales, fairs/exhibitions, and citizen-education programs, with little attention paid to housing-use programs (refer to Section 3.1.2).

Accordingly, various researchers have discussed the initiation of urban farming by utilizing barren land, building on rooftops, open public spaces, and open spaces within apartment complexes (refer to Section 3.2.1). We consider open spaces within apartment complexes to have the greatest potential for the following reasons. First, the ratio of apartments to total housing reached 0.67 in seven metropolitan cities (i.e., Seoul, Busan, Daegu, Incheon, Gwangju, Daejeon, and Ulsan) in Korea in 2022 [15]. Second, apartments have sufficient spaces that can be utilized for farming, including gardens, flowerbeds on the first floor, patios, and rooftops.

Therefore, there are numerous opportunities for urban farming in apartment complexes, and such activities can help foster a sense of community. This topic is also worthy of research because it makes it possible to promote housing-use programs. However, urban farming in apartment complexes has been relatively limited in scope and has often been confined to event-based, one-time projects. Therefore, this study aims to propose ways to enhance the sustainability of urban farming in apartment complexes. The primary objectives include deriving indicators of sustainability, analyzing their importance, and subsequently suggesting specific strategies for enhancing the sustainability of urban farming in apartment complexes. Although this study focuses on apartment complexes in Korea, it is anticipated that it will provide valuable insights applicable to similar residential communities abroad.

2. Materials and Methods

2.1. Scope of Our Study

2.1.1. Apartments

Based on the classification of the “Enforcement Decree of the Building Act,” among multi-unit dwellings, dwellings with more than five floors are defined as apartments [16]. In this study, we targeted apartment complexes in cities broadly and apartment complexes in seven metropolitan cities specifically. We considered apartments in Seoul to calculate available area for urban farming in apartment complexes (refer to Section 3.1.3).

2.1.2. Metropolitan Cities

Metropolitan cities are one of Korea’s administrative divisions. Among cities with a population of more than 1 million, the official designation includes six cities from Busan Metropolitan City to Ulsan Metropolitan City (

Table 1. Current statuses of seven metropolitan cities [11,15].

Classification	Average	Seoul	Busan	Daegu	Incheon	Gwangju	Daejeon	Ulsan
Area (km2)	776	605	771	885	1067	501	540	1063
Population (×1000)	3149	9419	3309	2357	2978	1426	1445	1106
Percentage living in apartments 1	67%	60%	69%	75%	66%	81%	75%	74%

¹ Percentage living in apartments = apartment units divided by total housing units.

). Although there are additional cities with populations of more than 1 million, there are no additional designated metropolitan cities. “Seoul Special City” has characteristics similar to those of metropolitan cities, but it is the capital of South Korea and is larger than other metropolitan cities, leading to several differences in authority, status, and autonomy.

As the distinction between “special city” and “metropolitan city” does not affect the results of this study, we included one special city and six metropolitan cities in our definition of metropolitan cities for convenience. We conducted a survey and analysis of each city’s ordinances, responsible departments, and status of ongoing programs.

2.2. Methodology of Our Study

2.2.1. Development of the Study

Our research methods can be broadly categorized into four approaches (Figure 1). First, we defined the direction of this research by examining theories of urban farming. We also analyzed recent research trends through a literature review and defined the factors that differentiate this study from published work. In the second phase of indicator selection, we derived the final indicators in three steps.

In the first step, we reviewed theories and previous studies of urban farming to derive indicators of sustainability of urban farming in apartment complexes. For the same purpose, we conducted an analysis of media articles. These articles were examined through a keyword search on Korea’s representative search portal site, “N.” Considering that South Korea has an extremely high ratio of apartments to other housing types, when the keyword “apartment” was utilized, the number of returned articles was enormous. Articles published within the last two years were targeted, and related articles were searched using the keywords “urban farming”, “apartment”, and “multi-unit dwelling”. From these articles, we directly derived indicators related to the sustainability of urban farming in apartment complexes, validating two articles per month and retrieving a total of 48 articles. As this study aimed to ensure the sustainability of urban farming in apartment complexes in South Korea, we targeted only theories, research papers, and media articles related to Korea for indicator derivation.

Second, we classified the indicators into a hierarchy in two stages based on findings from previous studies and conducted a preliminary categorization into six areas and 21 indicators.

Third, we selected and stratified the final indicators. To this end, we conducted in-depth interviews and pilot surveys of experts in relevant fields (e.g., architectural designers, landscape designers, agriculturalists, academics, and researchers). In the third phase of our study, we conducted a survey of experts on urban farming using the analytic hierarchy process (AHP) and analyzed the importance of each indicator. In the fourth phase, based on the results derived from indicator selection and importance analysis, we identified appropriate policy directions for facilitating urban farming in apartment complexes.

2.2.2. AHP Research Methodology

Thomas L. Saaty developed the AHP as a methodology to address multi-criteria decision problems. It is utilized to make final decisions by dissembling complex decision problems into a hierarchical structure and evaluating and combining the relative values of each criterion and alternative.

The AHP can be utilized to solve problems related to decision-making, priority setting, and risk assessment. In this study, we utilized the AHP to determine the priority and importance of indicators (fields and items).

The following phases were involved in utilizing the AHP in this study.

In the first step, the initial indicators were preliminarily categorized and stratified. In the preliminary categorization stage, we considered factor hierarchy based on the results of previous studies. Final stratification was performed based on the results of in-depth interviews and a pilot survey.

Second, the surveyor evaluated each indicator through pairwise comparisons to determine the relative importance of indicators for each class. The questionnaire survey was conducted using a seven-point scale.

Third, the weights of indicators were estimated using the eigenvalue method. Weights refer to the priority vector indicating the relative importance of indicators. By comparing all indicators and deriving relative comparison scores, it was possible to calculate a numerical value for each indicator representing its priority.

Finally, a crucial consistency verification was conducted in the AHP methodology. If the consistency ratio (CR) is close to zero, then the consistency of the survey results is considered to be high. In general, if the CR is less than 0.1, then a survey is considered to be a valid survey satisfying consistency [17]. Mathematically, the CR is defined as shown below.

$$\mathrm{C}\mathrm{I}\left(\mathrm{C}\mathrm{o}\mathrm{n}\mathrm{f}\mathrm{i}\mathrm{d}\mathrm{e}\mathrm{n}\mathrm{c}\mathrm{e} \mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x}\right)=\frac{{\mathsf{\lambda }}_{\mathrm{m}\mathrm{a}\mathrm{x}}-\mathrm{n}}{\mathrm{n}-1}$$

(1)

λ_max = Largest Eigenvalue

(2)

$$\mathrm{C}\mathrm{R}=\frac{\mathrm{C}\mathrm{I}}{\mathrm{R}\mathrm{I}(\mathrm{R}\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{o}\mathrm{m} \mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x})}$$

(3)

We used the “face-to-face survey” method to obtain raw data for AHP analysis. Analysis methods can be roughly divided into online and offline methods. However, the online method was excluded from this study as it was impossible to provide detailed explanations of indicators to respondents by that method (refer to Section 4.1.3). The collected raw data were verified for consistency using Excel 2016.

3. Theory and Literature Review

3.1. Urban Farming

3.1.1. Concepts and Features of Urban Farming

According to the Act on Development and Support of Urban Agriculture, urban farming refers to the actions included in the “Presidential Decree”: cultivating and growing crops, trees, and flowers utilizing diverse living spaces or land and buildings in urban areas [13].

The acts included in the Presidential Decree are limited to the cultivation of crops as a hobby and for leisure, study, and experience, meaning that the cultivation of agricultural products for sale is not recognized as urban farming. This choice was made in consideration of the fact that if urban farming were to expand into a profit-oriented business, it would have a huge impact on traditional farms. Therefore, because urban farming presents limited business possibilities, it is necessary instead for it to become self-sustaining based on public support. Therefore, policies to ensure the sustainability of urban farming should be systematically implemented by the central government or local governments. The indicators of urban farming initiation highlighted in this study could become important guidelines for policy design.

3.1.2. Urban Farming Types

Urban farms can be classified as (1) housing use, (2) neighborhood living area, (3) urban, (4) farm/park, and (5) school (

Table 2. Types of urban farming [13].

Types	Details
Housing use	Urban farming using the interior, exterior, railings, and rooftops of buildings such as houses and multi-unit dwellings, or land around buildings such as houses and multi-unit dwellings
Neighborhood living area	Urban farming using land located in neighborhood living areas around houses and multi-unit dwellings
Urban	Urban farming using the interior, exterior, and rooftops of high-rise buildings in the city center or land near high-rise buildings in the city center
Farm/park	Urban farming using farms or city parks
School	Urban farming using school land and buildings for the purpose of student learning and experience

). Housing use, neighborhood living area, and urban farms are implemented largely voluntarily by the private sector because it is difficult for the public to secure land for an urban-farming project. farm/park and school farms are implemented through public programs because separate land security is not required. This study focused on housing-use urban farming.

3.1.3. Estimation of the Available Area for Urban Farming in Apartment Complexes

The types of urban spaces in which urban farming can be implemented are summarized in

Table 3. Spaces available for urban farming [6].

Categories		Space in Use
Residential spaces	Interior	Entrance, Patio, Kitchen, etc.
	Exterior	Flowerbeds of a building entrance, Rooftop, Garden, etc.
Commercial & Industrial spaces	Interior	Lobby, Office, Corridor, Lounge, etc.
	Exterior	Rooftop etc.
Public land		City parks, Privately-owned public spaces, Schools, Hospitals, Welfare facilities, etc.
Street spaces		Fruit trees, Roadside trees, Roadside, Traffic island, etc.
Undeveloped lands		Withholding of development, Unused land
Other		Spare space in the city, New space created through wall removal

. Among those spaces, apartment complexes are residential spaces where agricultural activities are possible in interior residential spaces (e.g., entrance, patio, and kitchen) and outdoor residential spaces (e.g., flowerbeds at the entrance, rooftop, and garden).

There are various criteria for estimating the area of land available for urban farming (

Table 4. Usable areas for urban farming [18].

Categories			Scoring Criteria
Residential spaces	Detached housing areas	Green areas on sites	Area × 0.5
		The rooftop	Area × 0.3
	Apartment housing areas	Green areas on sites	Area × 0.5
		Indoor areas	1 m2 per household
Commercial & Business spaces		Green areas on sites	Area × 0.5
		The rooftop	Area × 0.3
Residential & Commercial spaces		Green areas on sites	Area × 0.5
		The rooftop	Area × 0.3

) [18]. According to these criteria, in apartment complexes, approximately 50% of green spaces within apartment complexes are considered to be available for urban farming. If this criterion is applied to the city of Seoul, it is possible to estimate the area of land available for urban farming in the city. According to Article 42 of the Building Act, when buildings (including apartments) on a land area larger than 200 m² are constructed, it is possible to estimate landscape areas in accordance with the ordinances of relevant local governments [19]. As each metropolitan city has different ordinances, we calculated available area based on Seoul as a representative city in this study. According to Article 24 of the Seoul Metropolitan Government Ordinance on Buildings, buildings (including apartment buildings) with a total floor area of more than 2000 m² must set aside a minimum of 15% of their space for landscaping [20]. As a landscape area includes approximately 30% green space and landscaping facilities (e.g., benches and ponds), the ratio of pure green space areas to the land area is approximately 0.1. However, a number of apartments in Seoul have landscape areas higher than 30% based on recent trends, with the area set aside for landscaping sometimes reaching more than 50% of the total area. Therefore, the ratio of green space area to the land area of apartments in Seoul is approximately 0.1 to 0.2, and the land area available for outdoor urban farming can be estimated to range from 5% to 10% of the total land.

The indoor standard for available urban farming area within apartment complexes is 1 m² per unit. As there are 1,851,242 apartments in Seoul, we can estimate that 1,851,242 m² is available urban farming [15]. Considering that there are large areas available for urban farming in apartment complexes, the relevance of this study is sufficiently proven.

3.1.4. Reviewing Urban Agriculture Practices in Apartment Complexes

In the operation of urban agriculture in apartment complexes, the key stakeholders are broadly categorized into three entities: the central government, the local government, and private organizations. There are two main operation types: relevant departments and dedicated departments.

A relevant department may temporarily or partially support urban agriculture activities as part of its existing functions, while the operation of a dedicated department involves the assignment of permanent staff of one or more individuals specializing in the tasks related to urban agriculture. The specific operators and types of operations are outlined in

Table 5. Statuses of departments in charge of urban farming in apartment complexes.

Classification		Organizations	Departments		Dedicated Personnel (No.)
			Type	Name of Departments
Central government		Ministry of Agriculture, Food and Rural Affairs	×		1
		Rural Development Administration	×		0
Local governments	Seoul	Seoul Metropolitan Government	Relevant department	Agricultural Support Team	1
		Agricultural Technology Center	Responsible department	Department of Agricultural Education	7
	Busan	Busan Metropolitan Government	Responsible department	Urban Agriculture Team	4
		Agricultural Technology Center	Responsible department	Civic Agricultural Team	7
	Daegu	Daegu Metropolitan Government	Responsible department	Urban Agriculture Team	3
		Agricultural Technology Center	Responsible department	Department of Urban Agriculture	12
	Incheon	Incheon Metropolitan Government	×		0
		Agricultural Technology Center	Responsible department	Department of Urban Agriculture	8
	Gwangju	Gwangju Metropolitan Government	×		0
		Agricultural Technology Center	Responsible department	Urban Agriculture Team	5
	Daejeon	Daejeon Metropolitan Government	×		0
		Agricultural Technology Center	Responsible department	Urban Agriculture Team	3
	Ulsan	Ulsan Metropolitan Government	×		0
		Agricultural Technology Center	Relevant department	Department of Urban Agriculture	2
Private organizations	Commissioned by the government	Urban Agriculture Support Center (5 in Seoul and 1 in Incheon)			N/A
	Self-operation	Urban Agriculture Network (1 in Seoul, 1 in Busan, 2 in Incheon, and 1 in Ulsan)
		Korea Urban Agriculture Corporation (1 in Seoul, 1 in Gwangju, and 1 in Daejeon)
		Urban Farmers Co., Ltd. (1 in Seoul and 2 in Incheon)
		Urban Farmer (5 in Seoul and 4 in Incheon)
		Other weekend farms, weekend vegetable gardens, etc.

.

The central government includes the Ministry of Agriculture, Food, and Rural Affairs and the Rural Development Administration, although there is no department dedicated solely to urban farming. However, the Ministry of Agriculture, Food, and Rural Affairs includes one person in charge of urban farming. This allocation of resources indicates that support for urban farming occurs largely at the level of local governments and private organizations, rather than at the level of the central government. Local governments were examined by focusing on the governments of the seven metropolitan cities that were the targets of this study. We comprehensively examined Agricultural Technology Centers, which operate directly under City Hall, which oversees municipal tasks, as well as the metropolitan government. Busan and Daegu have departments responsible for urban farming in their City Halls, whereas Seoul has a relevant department with only one person in charge of urban farming. Additionally, the cities of Incheon, Gwangju, Daejeon, and Ulsan do not have any dedicated departments in their City Halls. The Agricultural Technology Center in each city has a department responsible for urban farming, as well as a dedicated workforce ranging in size from 2 to 12 personnel. All of the cities except for Busan and Daegu have Agricultural Technology Centers that cover all tasks involved in the planning, implementation, and management of urban farming.

Private organizations can be divided into those commissioned by the government and those that are self-operated. The main government-commissioned organization is the Urban Agriculture Support Center, which operates six offices (five offices in Seoul and one in Incheon). This organization focuses mainly on tasks supporting farming, such as resident education, counseling office operation, seed support, and crop-cultivation support. Self-operated organizations include Urban Agriculture Network, Korea Urban Agriculture Corporation, and Urban Farmers. Their tasks mainly involve distribution and direct transactions, rather than support for farming.

In this way, the status of dedicated departments and personnel responsible for urban agriculture in apartment complexes varies by region, with many regions relying on central agencies rather than establishing separate departments within local governments.

3.1.5. The Current Status of the Program Promoting Urban Agriculture in Apartment Complexes

The current urban agriculture program being pursued by local governments operates a total of six types of subprograms, including the five types classified on 12 March and an additional miscellaneous type covering all of these (

Table 6. Programs to promote urban farming in seven metropolitan cities.

Types	Program	Seoul	Busan	Daegu	Incheon	Gwangju	Daejeon	Ulsan
School	Urban farming exchange experience (between cities, provinces, and institutions)	○	○		○	○
	Urban farming fair/exhibition	○	○	○	○		○
	Urban farming tour (experience campaign)	○	○	○		○	○	○
	Horticultural therapy (healing) program (farm)	○		○	○	○	○	○
	Nature-experience school and nature learning center for citizens	○					○
	Home Horticultural Plant Hospital (General Plant Hospital)	○	○
	Urban farming expert training	○	○		○		○	○
	Educational program for farmers		○
	Urban farming program (for the general public)	○	○	○	○	○	○	○
	Education for female farmers		○
	Green U-turn training (for those returning to rural areas)		○	○		○		○
	Education for farming tips (by location and crop)	○	○	○	○	○	○	○
	Overseas training for farmers		○
	Urban farming startup support	○			○			○
	Operation of the information support center for urban farming	○	○
	Publication of urban agriculture books	○		○	○
	Pilot project of farm work safety model		○		○
	Support for research group initiation		○	○		○
	Pest monitoring and technical guidance		○
	Educational donation (youth psychology, emotional stability)			○
Farm/park	Urban family weekend farmer	○	○		○	○
	School farm	○	○	○	○	○	○	○
	Silver farm	○			○
	Farm for households with more than three children	○					○
	LED plant factory			○
	Sale of vegetable garden	○	○	○	○	○	○	○
Housing use	Apartment-building porch (green curtain) project	○
	Rooftop garden	○	○		○		○	○
	Community garden	○		○	○	○	○	○
Neighborhood living area	Rooftop garden	○	○		○		○	○
Urban	Community garden	○		○	○		○	○
Others	Urban farming for local food production	○			○	○
	Rental of urban farming equipment	○	○		○

). There are a total of 33 such programs in operation, with 20 focusing on schools and 6 on farm-park types.

In contrast, only three programs are of the communal-housing type, indicating that urban agriculture is more active in places where public intervention is easier, such as in schools or city parks, rather than in private homes or private buildings. Among the programs, those relating to urban agriculture education and school farms are the most widely promoted nationwide. This finding suggests that urban agriculture in schools is less constrained in space, has sufficient participants in the form of students, and faces fewer obstacles in program operation due to public support for programs ranging from basic education to agricultural practical training.

3.2. Literature Review

3.2.1. Research Trends in Previous Studies

The indicators of urban farming initiation derived from our literature review are presented separately in Section 4, where we analyze relevant research trends and review the factors that differentiate this study from previously published work (

Table 7. Previous studies.

Category	Reference	Keywords	Methodology
Before 2011	[21]	Definition of urban farming concepts, Overseas cases, Legislative measures	Review of relevant laws, Literature review, Survey
	[22]	Klein Garten, Common vegetable gardens, Operational systems, Institutionalization methods	Overseas case study (Vegetable gardens, system of relevant laws) A case study in Korea (Actuality of utilization, survey)
	[23]	Klein Garten, Family park, Regional regeneration policy, Case study of Japan	Literature review Present-condition investigation Interview
	[24]	Urban farming status survey, Urban farming categorization, Participant characteristics	Literature review Cluster analysis (logistic regression)
After 2011	[25]	Participation survey, Value evaluation, Public support	Participation survey Contingent valuation method
	[26]	Sustainability, Spatial programs, Basic design	Reviews on theories and previous studies Analysis of target-site status Resident survey Design
Recent trends	[27]	Biological control, Companion planting ratio, Green roofs	Experiment Statistical analysis
	[28]	Garden box, Edible plants, Injection mold, Air pollution	Case study Empirical study
	[29]	Urban agriculture, Life cycle assessment, Environmental impacts, Sustainable agriculture	Life cycle assessment Literature search Meta-analysis
	[30]	Urban agriculture, Urban agroecology, Ecosystem services, Sustainability	Literature review

). Specifically, we reviewed urban-farming-related studies by dividing the studies into those examining the periods before and after the enactment of the 2011 Act on Development and Support of Urban Agriculture.

(1)

Research before 2011

During the period before the enactment of the Urban Farming Act, a majority of studies focused on the conceptualization of urban farming, the introduction of programs overseas, and institutionalization plans. There were numerous cases of programs to promote urban farming in other highly developed countries, including the UK, Japan, and Germany.

Kang et al. focused on domestic urban farming in South Korea and suggested legal and institutional revitalization measures based on overseas cases [21]. Hwang introduced the concept of the “Klein Garten” from Germany [22]. The system in which a vegetable garden called a “Klein Garten” could be jointly operated to promote health and emotional connections was introduced in combination with measures to institutionalize this concept in Korea. Choi reviewed a case in which Japan had introduced the “Klein Garten” concept as part of regional regeneration policies, repurposing several spaces into rest areas and family parks for local residents [23]. Hwang et al. categorized urban farming based on the results of a nationwide survey and clarified the features of the participants in each type [24]. Based on the results of their analysis, plans to institutionalize and support urban farming were suggested.

(2)

Research after 2011

Since the enactment of the Urban Farming Act and the facilitation of public support, there has been an increasing focus on case studies of urban-farming programs in Korea, as well as basic plans and designs for creating urban agricultural parks.

Heo targeted citizens participating in weekend vegetable gardens in Seoul and researched people’s willingness to pay for specific weekend vegetable-garden programs [25]. This approach allowed the identification of programs preferred by citizens and the analysis of investment of public resources, as well as the ways in which citizens benefit from such programs. Lee et al. considered real-world target sites, where they planned and designed urban agricultural parks [26]. They derived planning indicators from an analysis of the current statuses of target sites and resident surveys and completed basic designs. In summary, there have been some studies since 2011 focusing on the practical implementation of urban farming.

(3)

Recent research trends

Park et al. analyzed the effects of the companion planting ratio of marigolds on the growth of and pest control in Chinese cabbage in rooftop urban farming [27]. Cheong conducted an empirical study to develop a multifunctional vegetable-garden box and suggested appropriate vegetable-garden boxes for each crop based on case studies and empirical studies of crops and boxes that can be utilized in urban farming [28]. In a study by Dorr et al., the environmental impact of urban agriculture was assessed through life cycle assessment (LCA) [29]. In a study by Gómez-Villarino et al., the benefits and potential of urban agriculture were elucidated through a literature review employing an agroecological approach [30]. Through this work, the sustainability of urban agriculture was examined. In general, recent research has focused on crops and cultivation methods appropriate for urban farming.

3.2.2. Differentiation Factors Associated with This Research

The main results of our literature review can be summarized as follows. First, research targets have changed over time. During the period before the enactment of urban farming legislation in 2011, most studies focused on emulating overseas cases and on measures for introducing such systems in Korea. After the enactment of the Urban Farming Act, studies mainly focused on the introduction of urban farming in Korea, evaluation of publicly funded projects, and preference surveys of urban farming types.

Recent research trends include the introduction of appropriate crops and cultivation methods for urban farming as urban farming has become more widespread. Second, excluding very recent studies, most studies have attempted to derive general and comprehensive conclusions regarding urban farming.

As urban farming is now in the application and initiation stage, rather than the introduction stage, it is imperative to provide specific research results. Third, it was challenging to find research on apartment complexes, which account for the greatest proportion of housing types in cities. This lack of data can be attributed to urban farming primarily occurring in yards and rooftops of detached houses and on idle land associated with public facilities (e.g., schools and government offices).

In this study, we attempted to target research subjects and apply methods that have not been discussed in previous studies. By targeting apartment complexes, we intend to derive indicators of urban-farming initiation and propose policies to ensure the sustainability of urban farming. Such policy proposals can be considered the main factor differentiating this study from the existing literature.

4. Results

4.1. Indicator Selection for Facilitating Urban Farming in Apartment Complexes

4.1.1. Indicator Derivation

(1)

Review of urban farming theories

First, we derived a total of 15 indicators through a review of urban farming theories (Table 8) [31,32,33,34,35,36]. Each category and the corresponding derived indicators are described in detail below.

In the “complex condition” category, we derived three indicators: “number of households”, “availability of rooftops for use”, and “low floor area ratio”. As successful urban farming on a scale suitable for a business requires a certain amount of apartment area and number of household members, “number of households” was chosen as an indicator. As rooftop farming is gaining popularity not only in apartments, but also in public buildings and commercial facilities, “availability of rooftops for use” was also chosen as an indicator. “Low floor area ratio” was also derived as an indicator because securing sunlight is important for farming.

Four indicators were chosen in the category “farming conditions”, all of which are physical factors. Among them, “high sunlight” overlaps with “low floor area ratio,” but we selected this indicator because sunlight is considered to be significant in urban farming theories. “Biotope area rate” refers to the ratio of land allocated to natural processes to the total land area. According to Article 10-2 of the Seoul Metropolitan Government Enforcement Rule of Ordinance on Urban Planning, the corresponding formula is defined as shown below [37]. “Biotope area rate” was recently highlighted and was selected as an important indicator for carrying out urban farming in the outdoor areas of apartments.

Biotope area rate (%) = Natural circulation function area/Total area × 100

Biotope area rate (%) = ∑(Converted area per cover type) + ∑(Converted area per planting type)/Total area × 100

Altogether, four indicators were chosen in the “technical and management support” category. Among them, the absence and presence of “urban-farming-related NGOs within administrative districts” have been highly emphasized in theory reviews. Urban-farming-related programs are mostly led or supported by public organizations and advanced in cooperation with NGOs. Consequently, the presence of urban-farming-related NGOs within administrative districts is closely related to the facilitation of relevant programs.

The three indicators in the category “public funding” were selected because numerous urban-farming programs are currently supported by public organizations, as mentioned previously.

Finally, one indicator was selected in the “status of residents” category. Kim et al. indicated that people in their 40s or older had immense interest in items related to the usage of vegetable gardens and maintenance of urban farming [36]. Consequently, as the age group of people over 40 was found to be the most dominant in terms of interest in urban farming and actual experiences, age over 40 years was selected as an indicator.

(2)

Literature review

Overall, 15 indicators were derived from our literature review [1,6,7,9,21,22,23,24,25,26,27,28,29,30,38,39,40,41,42,43,44,45,46], of which 12 were also derived from theoretical reviews. The following three indicators were derived solely from the literature review. The “vicinity of industrial areas (environmental aspect)” indicator in the category “location conditions” was derived from studies related to brownfields, which have recently become an important issue [39]. A brownfield is a location where land is being used for purposes with significantly less value compared to the potential value of the land due to the presence of or concerns regarding soil contamination. Brownfields are used mostly as industrial land [39]. Soil contamination was chosen as an indicator because contaminated soil is an inappropriate environment for agriculture and requires minimum separation. The “ease of securing cultivation soil” indicator in the category “farming conditions” was selected because different soils are required for cultivating different varieties of crops and because the growth features of herbaceous plants vary with soil conditions [41]. The “ratio of people with high crop-cultivation experience” indicator in the category “resident status” has been considered in numerous studies, including those by Jang et al., and these studies have found that the absence or presence of crop-cultivation experience massively contributed to experiencing and adapting to urban farming [9,42].Analysis of media articles

The indicators derived from article analysis include “absence/presence of main roads (environmental aspect)”, “age of apartment building”, and “low social-activity rate”. The variable “absence/presence of main roads” is significant because it determines whether exhaust gas emissions from high traffic volumes will have a significant impact on crops and consumers. “Age of apartment building” was found to be related to the effectiveness of urban farming. Newly constructed apartments can leave residents with a poor impression of the building as a result of simplistic decoration styles. Additionally, some articles stated that old apartment buildings have a high possibility of undergoing renovation, causing residents to oppose farming in some apartments. “Low social-activity rate” is an indicator related to the current status of urban farmers. Farming typically takes place during the day, so a low social-activity rate of individuals in apartment complexes is closely related to their having more free time to participate in farming.

Table 8. Indicator derivation and preliminary categorization.

First Step				Second Step
Indicator Derivation	Literature Review 1	Previous Studies 2	Media Articles 3	Preliminary Categorization
Absence/presence of main roads (environmental aspect)			○	Location condition
Vicinity of industrial areas (environmental aspect)		○	○
Size (number of households)	○	○		Complex condition
Age of apartment building			○
Availability of rooftops for use	○	○	○
Low floor area ratio	○
Security of water	○	○		Farming condition
High sunlight	○	○
High greenspace rate	○	○	○
Biotope area rate	○		○
Ease of securing cultivation soil		○
Presence of related specialized organizations within administrative districts	○	○	○	Technical and management support
Presence of related programs within administrative districts	○	○	○
Presence of related case reports within administrative districts	○	○	○
Presence of urban-farming-related NGOs within administrative districts	○	○	○
Presence of relevant departments within administrative agencies	○	○	○	Public funding
Ordinance for administrative agency support and allocated budget	○	○	○
Presence of similar support projects within administrative districts	○	○	○
Proportion of people in their 40s or above	○		○	Status of residents
Low social-activity rate			○
Ratio of people with high levels of experience in crop cultivation		○

¹ [31,32,33,34,35,36]; ² [1,6,7,9,21,22,23,24,25,26,27,28,29,30,38,39,40,41,42,43,44,45,46]; ³ Articles searched from the search portal site “N.”.

Table 8. Indicator derivation and preliminary categorization.

First Step				Second Step
Indicator Derivation	Literature Review 1	Previous Studies 2	Media Articles 3	Preliminary Categorization
Absence/presence of main roads (environmental aspect)			○	Location condition
Vicinity of industrial areas (environmental aspect)		○	○
Size (number of households)	○	○		Complex condition
Age of apartment building			○
Availability of rooftops for use	○	○	○
Low floor area ratio	○
Security of water	○	○		Farming condition
High sunlight	○	○
High greenspace rate	○	○	○
Biotope area rate	○		○
Ease of securing cultivation soil		○
Presence of related specialized organizations within administrative districts	○	○	○	Technical and management support
Presence of related programs within administrative districts	○	○	○
Presence of related case reports within administrative districts	○	○	○
Presence of urban-farming-related NGOs within administrative districts	○	○	○
Presence of relevant departments within administrative agencies	○	○	○	Public funding
Ordinance for administrative agency support and allocated budget	○	○	○
Presence of similar support projects within administrative districts	○	○	○
Proportion of people in their 40s or above	○		○	Status of residents
Low social-activity rate			○
Ratio of people with high levels of experience in crop cultivation		○

¹ [31,32,33,34,35,36]; ² [1,6,7,9,21,22,23,24,25,26,27,28,29,30,38,39,40,41,42,43,44,45,46]; ³ Articles searched from the search portal site “N.”.

4.1.2. Indicator Selection and Stratification

(1)

In-depth interviews

In-depth interviews of experts (ten experts in four fields) were conducted from 5 to 14 April 2023. After collecting expert opinions, we added, integrated, modified, and deleted several indicators, and the results are presented in

Table 9. Results of in-depth interviews with experts.

Interviewee			Answer	Application
Fields	Affiliation	Position
Architectural design	U Urban Planning & Architecture	CEO	“High greenspace rate” and “biotope area rate” should be integrated because they are similar concepts.	Integration
	M Architects	Director	Convenient transport, represented as, e.g., “distance from the city center, sub-center, and metropolitan connection points”, is important.	Addition
Landscape design	S Landscape	Manager	“Drainage facility” and “security of water” in farming conditions are similar concepts that should be integrated.	Integration
	C Engineering	Team manager	If a “wind path” is blocked, then crops within apartment complexes may not grow well.	Addition
Agriculture	D.G. Agricultural Technology Center	Rural development officer	If water is not properly circulated within apartment complexes, it not only has a negative impact on the durability of the building, but also results in mold and moss, damaging the aesthetics of the apartments. “Drainage facility” was added.	Addition
	D.S. Agricultural Technology Center	Rural development officer	Areas vulnerable to “flood damage” should be avoided.	Addition
	Urban Agriculture Service Center	Rural development officer	“Revitalization of community” within apartment complexes is important.	Addition
Academia/Research	L Research Institute	Research fellow	“Absence/presence of main roads” and “Vicinity of industrial areas” are similar indicators that should be integrated into “Separation from industrial zones”. “Presence of relevant programs within administrative districts” and “case reports” in the category “technical and management support” should be integrated.	Integration
	A&U Research Institute	Research fellow	In apartments, repairs are carried out according to the management period after the completion of construction. “Repair time” is more important than “age of apartment building” because satisfying the physical conditions of urban farming in line with the timing of apartment repairs can increase efficiency.	Modification
			The presence or absence of “persons in charge of urban farming in apartment maintenance offices” is important.	Addition
	K University	Professor	Regarding resident status, the “proportion of people in their 40s or older” is important, but the “proportion of women” is also crucial.	Modification
Photos of Interviews

.

(2)

Pilot survey

A pilot survey was conducted from 20 to 25 April 2023, involving eight experts (two experts in each of four fields). According to our analysis using the AHP, the “wind path” indicator with the lowest weight was deleted (

Table 10. Selection indicators for activating urban farming in apartment complexes.

Fields	Primary Indicators	a			b		c	Final Indicators
		a-1	a-2	a-3	b-1	b-2
A	Absence/presence of main roads (environmental aspect)			○	●		●	Separation from industrial zones (environmental aspect)
	Vicinity of industrial areas (environmental aspect)		○	○	●
	Distance from the city center, sub-center, and metropolitan connection points				▲	△	△	High accessibility (traffic)
	Non-flooded area				▲		▲	Non-flooded area
B	A certain size (number of households)	○	○				○	Size (number of households)
	Age of apartment building			○	△		△	Apartment repair/renovation time
	Availability of rooftop use	○	○	○			○	Availability of rooftop use
	Low floor area ratio	○					○	Low floor area ratio
C	Security of water	○	○		●		●	Security of water/Drainage facility
	Drainage facility				▲
	High sunlight	○	○				○	High sunlight
	High greenspace rate	○	○	○	●		●	High greenspace rate/biotope area rate
	Biotope area rate	○		○	●
	Ease of securing cultivation soil		○				○	Ease of securing cultivation soil
	Wind path				▲	×	×	-
D	Presence of related specialized organizations within administrative districts	○	○	○			○	Presence of related specialized organizations within administrative districts
	Presence of related programs within administrative districts	○	○	○	●		●	Presence of relevant programs within administrative districts (cases)
	Presence of related case reports within administrative districts	○	○	○	●
	Presence of apartment maintenance-office managers				▲		▲	Presence of apartment maintenance-office managers
	Presence of urban-farming-related NGOs within administrative districts	○	○	○			○	Presence of urban-farming-related NGOs within administrative districts
E	Presence of relevant departments within administrative agencies	○	○	○			○	Presence of relevant departments within administrative agencies
	Ordinance for administrative agency support and allocated budget	○	○	○			○	Presence of administrative agency support, ordinance and budget
	Presence of similar support projects within administrative districts	○	○	○			○	Presence of similar support projects within administrative districts
F	Proportion of people in their 40s or above	○		○	△		△	High proportion of women in their 40s or older
	Low social-activity rate			○			○	Low social-activity rate
	Percentage of people with high levels of crop-cultivation experience		○				○	Percentage of people with high levels of crop-cultivation experience
	Revitalization of community				▲		▲	Revitalization of community
A: Location condition B: Complex condition		C: Farming condition D: Technical and management support					E: Public funding F: Status of residents
a: Indicator derivation a-1: Literature review a-2: Previous studies a-3: Media articles		b: Indicator categorization b-1: In-depth Interviews b-2: Pilot survey					c: Final indicator selection

○: Selection ●: Integration △: Modification ▲: Addition ×: Deletion.

). Other opinions indicated that as the “distance from the city center, sub-center, and metropolitan connection points” indicator in the “location condition” field was unnecessarily detailed, modification to a more general indicator would be ideal. Consequently, we modified this indicator to “high accessibility (traffic)” to reflect this opinion. Accordingly, we derived a total of 22 final indicators in six fields.

4.1.3. Details of the Questionnaire

Prior to administering the questionnaire, we identified several parts that could confuse respondents and attached detailed explanations.

First, we clearly indicated and explained the purpose of facilitating urban farming in “apartment complexes.”

Second, the indicators “presence of related specialized organizations within administrative districts” in the “technical and management support” category and “presence of relevant departments within administrative agencies” in the “public funding” category appear to be similar, but we emphasized that these two indicators have very different meanings. Essentially, the former refers to the Urban Agriculture Support Center, which support programs with technology and management, whereas the latter refers to departments of administrative agencies that support them with financial resources.

Third, the indicators “presence of relevant programs within administrative districts (cases)” in the “technical and management support” category and “presence of similar support projects within administrative districts” in the “public funding” category also appear similar but are distinguished by the inclusion or non-inclusion of financial resources. Technology and management support can also be considered a part of financial resources, but in this study, the definition of “financial support” was limited to cost support for related projects. We thus clearly indicated the researchers’ intended meanings for items in the expert questionnaire that carried a possibility of misunderstanding.

4.2. Importance Analysis

4.2.1. Outline

The AHP technique was applied to the six fields and 22 indicators derived through the above-described indicator-selection process to conduct a survey of experts (refer to Table 10). Footnotes were also added to help the interviewees understand indicators assumed to be difficult to understand. The AHP expert survey targeted professionals (more than five years of work experience) with work or research experience related to urban farming among employees in four fields (i.e., architectural design, landscape design, agriculture, and academia/research). Overall, 80 questionnaires were distributed (20 questionnaires for each field). Following consistency verification based on the CR, only the 58 questionnaires that satisfied CR < 0.1 were validated and used in AHP analysis.

Table 11. Selection criteria for urban-farming experts and the return rate of questionnaires.

Fields	Selection Criteria for Urban Farming Experts			Available Questionnaires
	Affiliation	Career	Degree	a	b	c
Architectural design	U Urban Planners & Architects M Architects S Architects & Engineers W Architects	More than 5 years	More than Bachelor’s degree	20	15	75%
Landscape design	S Landscape Designers C Engineers H Architects	More than 5 years		20	14	70%
Agriculture	D.G. Agricultural Technology Center S Agricultural Technology Center D.S. Agricultural Technology Center Urban Agriculture Service Center	More than 7 years		20	12	60%
Academia/ Research	National Institute of Agricultural Sciences A&U Research Institute L Research Institute K University	More than 5 years	More than Master’s degree	20	17	85%
Total				80	58	73%

a: The number of returned questionnaires, b: The number of available questionnaires, c: Effective rate.

summarizes the criteria for expert selection and questionnaire statuses.

4.2.2. Survey Results and Analysis

Analysis of the importance of each field revealed that public funding (0.249) was the most important, followed by technical and management support (0.219), status of residents (0.186), farming condition (0.131), complex condition (0.126), and location condition (0.089) (

Table 12. Importance of indicators for facilitating urban farming in apartment complexes.

Fields	Importance	Indicators		Importance	Ranking	Priority Analysis
A	0.089	A1	Separation from industrial zones (environmental aspect)	0.039	12
		A2	High accessibility (traffic)	0.026	17
		A3	Non-flooded area	0.024	18
B	0.126	B1	Size (number of households)	0.024	18
		B2	Apartment repair/renovation time	0.028	16
		B3	Availability of rooftop use	0.058	7
		B4	Low floor area ratio	0.016	22
C	0.131	C1	Security of water/Drainage facility	0.032	15
		C2	High sunlight	0.035	13
		C3	High greenspace rate/Biotope area rate	0.041	11
		C4	Ease of securing cultivation soil	0.023	20
D	0.219	D1	Presence of related specialized organizations within administrative districts	0.045	10
		D2	Presence of relevant programs within administrative districts (cases)	0.065	5
		D3	Presence of apartment maintenance office managers	0.050	9
		D4	Presence of urban-farming-related NGOs within administrative districts	0.059	6
E	0.249	E1	Presence of relevant departments within administrative agencies	0.067	4
		E2	Presence of administrative agency support ordinance and budget	0.108	1
		E3	Presence of similar support projects within administrative districts	0.074	3
F	0.186	F1	High proportion of women in their 40s or above	0.019	21
		F2	Low social activity rate	0.033	14
		F3	Ratio of people with high crop cultivation experience	0.057	8
		F4	Revitalization of community	0.077	2
6 fields	1.000	22 indicators		1.000

Shading was applied to distinguish different fields, with the darker shading indicating higher importance in the respective field.

).

Public funding was chosen as the most important field, and its three indicators were ranked first, third, and fourth. “Ordinance for administrative agency support and allocated budget” was ranked as the first indicator, as it was taken to indicate that urban farming has been revitalized with support from administrative agencies. This result implies that projects led by private sectors become self-sustaining relatively early and that a connection with support projects of administrative agencies is important to ensuring the sustainability of urban farming in apartment complexes. “Presence of similar support projects within administrative districts” and “presence of relevant departments within administrative agencies,” which ranked third and fourth, respectively, can be considered as indicators underpinning this concept.

Technical and management support, which is the second-most-important field, is related to the capacity to transfer urban farming techniques and manage projects exclusively. Its indicators ranked in the upper-middle of the list (fifth, sixth, ninth, and tenth), implying that these indicators must be satisfied to ensure the sustainability of urban farming in apartment complexes. The “presence of urban-farming-related NGOs within administrative districts” indicator, which ranked sixth, was discussed in depth in the subjective items of the questionnaire. NGOs, which are organizations distributing necessary goods needed for farming, were considered to serve an important role in creating networks between apartment residents and administrative agencies. Previous studies have also highlighted many examples in which NGOs were included in urban-farming projects. NGOs play a role in mediating the interests and conflicts of various groups promoting urban-farming projects. The “presence of apartment maintenance-office managers” indicator, which ranked ninth, is related to the unity of residents. Urban farming is not focused on generating profit, and not all residents participating in urban farming are experts. Therefore, there should be a representative in each apartment complex who can coordinate and promote projects from the residents’ perspective. The “presence of related specialized organizations within administrative districts” indicator, which ranked tenth, emphasizes the importance of professional organizations that can support agricultural technology, such as the Urban Agriculture Support Center and Urban Agriculture Network.

“Status of residents” appeared to be the third-most-important category, indicating that the characteristics of residents who participate in farming can determine the success or failure of projects. Among the associated indicators, the “revitalization of community” indicator, which ranked second overall, is noteworthy. “Urban farming”, in the context of this study, refers to activities within apartment complexes, including activities performed by individuals and groups. The creation of a community with the common goal of urban farming is considered crucial. The ranking of “percentage of people with high levels of crop-cultivation experience” indicator, which ranked eighth, was expected to some extent. The “low social-activity rate” and “high proportion of women in their 40s or older” indicators scored in the mid-to-low end of the ranking system. As urban farming in apartment complexes is not large in scale, farming can be successful even if residents devote their time to it only during weekends. The experts also determined that the proportion of women in their 40s or older does not determine the success or failure of urban farming in apartment complexes.

The factor “farming conditions”, the physical conditions necessary for carrying out agricultural activities, was selected as the fourth-most-important indicator. The indicators “high greenspace rate/biotope area rate”, “high sunlight”, and “security of water/drainage facility” received moderate rankings of 11, 13, and 15, respectively. Appropriate farming conditions are essential for urban farming, but experts judged that human factors and social conditions were more important than the physical conditions of apartment complexes.

The “complex condition” and “location condition” categories, which ranked relatively low, also denote physical conditions associated with urban farming and can be interpreted similarly to the “farming conditions” factor. The most significant indicator among these is “availability of rooftop use”, in the “complex condition” category, which ranked seventh. The rooftops of older apartment buildings are often used only as evacuation spaces, but more recent apartment designs increasingly include uses such as “rooftop gardens (sky gardens)”. However, safety and drainage issues must be addressed before agricultural activities can be conducted. As apartment rooftops can provide very large spaces, rooftop-related indicators are assumed to be meaningful for facilitating urban farming within apartment complexes (refer to Section 3.1.3). The “apartment repair/renovation time” indicator in the “complex condition” category, which ranked 16th, emphasizes the efficiency of urban farming, as it was considered unimportant by experts. The experts determined that the improvement of physical environments in apartment complexes does not have a significant relationship with urban farming.

5. Policy Directions for Sustainable Urban Farming in Apartment Complexes

As mentioned in the introduction, despite its many advantages, urban farming has yet to be facilitated at a large scale owing to various obstacles. The insufficiency of related research, particularly research on apartments, which account for the largest share of a city’s residential sector, motivated this study. Furthermore, this study aimed to provide basic data related to urban-farming-related policies that have been actively promoted by local governments, including districts in Seoul and to facilitate urban farming projects’ becoming autonomous. Accordingly, we present plans to revitalize urban farming within apartment complexes based on indicator analysis and suggest four policy directions, as shown in Figure 2.

5.1. Plans to Prepare Departments in Charge of Urban Farming in Apartment Complexes

Urban farming in apartment complexes is still nascent, and public support is crucial for its growth. Consequently, it is necessary to secure dedicated work and financial resources within a management department. The “presence of relevant departments within administrative agencies” indicator had the greatest significance of all indicators in its category, according to the expert survey (E1, rank four). A review of the operational methods in Section 3.1.4 revealed that both the central government and local governments face a shortage of dedicated departments and specialized personnel.

To ensure the sustainability of related projects, securing financial resources from the central or local government is a prerequisite, and it is important to secure professionals in administrative agencies to increase effectiveness by investing these resources efficiently.

Therefore, it is necessary to establish a permanent organization specializing in urban farming in apartment complexes or to elevate existing relevant departments. When relevant tasks arise, it is essential to secure dedicated professional staff instead of partial support to manage urban farming.

The Agricultural Technology Center recently opened a new (or upgraded) department in charge of urban farming in apartment complexes, indicating that the importance of urban farming in apartment complexes is recognized. There are also more diverse organizations in the private sector. However, there is no organization solely dedicated to large-scale urban farming in multi-unit dwellings such as apartment complexes. Overall, the dedicated organizations in central and local governments in charge of overseeing the planning, execution, and managing of urban farming policies are insufficient to the task.

Urban-farming projects mostly involve weekend farms, urban vegetable gardens, and schools; there are no projects targeting multi-unit dwellings such as apartment complexes. As apartment complexes are residential areas, social consensus within apartment complexes regarding urban farming is required and the role of the public is crucial.

5.2. Revision of Ordinances in Support of Urban Farming and Budget Formulation

The indicator “Ordinance for administrative agency support and allocated budget” (E2, ranked first) ranked the highest in its category, per the expert survey. In Korea, specific ordinances are required to execute local government budgets. According to a review of the ordinances of seven metropolitan cities, there was no provision for urban farming in multi-unit dwellings such as apartment complexes.

We propose the following amendments to ordinances to ensure the sustainability of urban farming in apartment complexes. First, guidelines for implementing urban farming within apartment complexes are required. Conflicts arising from urban farming within apartment complexes can be prevented if the government defines implementation guidelines regarding location, crops to cultivate, activity time, and avoidance of damage to residents within apartment complexes. Second, regulations for support projects are required. It is necessary to define support measures for crops, farming equipment, and distribution management within ordinances or enforcement regulations. In particular, regarding distribution, it is necessary to provide public programs for promoting consumption within apartment complexes because sale of the crops is not permitted (refer to Section 3.1.1).

Budget was not considered separately because it is a product of related ordinances and enforcement regulations. However, even if the relevant laws are revised, there may be differences in budget depending on the government’s will to enforce them.

5.3. Urban-Farming Programs in Apartment Complexes

The expert survey results indicate that for the initiation of urban agriculture within apartment complexes, “Presence of related programs within administrative districts” (D2, rank five) is crucial. As urban-farming programs that are currently promoted by local governments focus on the school and farm/park types, there is a need to diversify these programs (Table 6). As urban agriculture is anticipated to have positive effects within apartment complexes, there is a need to expand housing-use programs.

In addition to the housing-use programs in Table 6, we propose the following programs that can be implemented in apartment complexes. The first is a joint-consumption program. As aforementioned, because urban agricultural products cannot be sold, we propose a program to establish a distribution system within apartment complexes so that producers can consume the food they grow.

The second is a community-revitalization program. The “revitalization of community” (F4, ranked second) indicator is crucial, according to the expert survey. As mentioned in the introduction, urban farming brings both direct (e.g., cultivation of agricultural products) and indirect (e.g., carbon reduction and better urban landscape) benefits. Among these benefits, the revitalization of community is a representative example.

Urban-farming projects in apartment complexes should be promoted in connection to revitalizing communities within apartment complexes. As urban farming is not a profit-driven project, residents and administrative agencies (professional organizations) that promote urban farming must play a central role. In particular, residents may face difficulties in communicating about urban farming if there is no existing community. There can be diverse programs mainly based on the crops they cultivate, such as shared restaurants, weekend meals, lettuce wraps, and kimchi making.

It is possible to foster a sense of community through programs in which people share food made of ingredients that have been cultivated communally. Therefore, it is expected that the revitalization of community, which is a major issue in Korean apartment complexes, can be solved through a combination of diverse community programs and urban farming.

5.4. Technical and Management Support from the Public

Urban farming in apartment complexes can be sustainable, rather than a one-time program, given continuous public technical and management support. In the expert survey, “technical and management support” was selected as the second-most-important indicator. Urban residents are considered non-experts in agriculture, so their level of participation in urban farming will be low unless continuous technical and management support is provided.

If apartment complexes cannot achieve the “presence of apartment maintenance-office managers” (D3, ranked ninth), then it would be reasonable to implement a corresponding program with instructors from rural areas. Apartment complexes are relatively large compared to other departments of urban agriculture and have large numbers of participants. Each autonomous district can have dedicated instructors from rural areas and manage a program to support urban farming in apartment complexes throughout the entire cycle, from vegetable-garden creation to crop cultivation.

Additionally, the indicator “presence of urban-farming-related NGOs within administrative districts” (D4, ranked sixth) is related to the sustainability of urban farming within apartment complexes. Groups or individuals promoting urban farming should consider linkages with NGOs, and the public sector must provide matching services. Such support programs can alleviate participant concerns regarding urban farming and contribute to voluntary and continuous agricultural activities, even after public support ends.

6. Discussion and Conclusions

6.1. Study Implications

In the previous section, we presented policy directions for improving the sustainability of urban farming in apartment complexes based on key indicators derived in this study. In this section, we will discuss the implications of this research based on the content presented above and examine its potential contributions.

First, these findings can contribute to the establishment of a public support system to ensure the sustainability of urban farming in apartment complexes. As aforementioned, urban farming in apartment complexes is gaining more recognition, especially in metropolitan areas where the amount of available urban land is decreasing continuously and the percentage of residents in collective housing is rising. In such metropolitan areas, which require social responses to the breakdown of community life within collective housing, urban farming goes beyond traditional crop production and is increasingly expected to provide health improvement, positive experiences, and leisure activities, thereby promoting community recovery.

However, the lack of profitability due to the prohibition on selling produce from urban farms presents a challenge for urban farming in apartment complexes, rendering public financial support essential. Furthermore, issues such as the need for mediation in public agreements, the lack of departments and staff for supervising and executing projects, and the need for technical support to encourage non-professional citizens to participate in agricultural activities in residential areas must be resolved.

We have discussed specific directions for policy improvement based on these issues, all of which have the advantage of minimizing practical implementation errors that may occur when designing relevant policies based on the key indicators derived in this study.

Financial, personnel, and technical support are vital for every field, and it is necessary to establish and implement a comprehensive support policy. With consistent recommendations for policies necessary for project implementation, stakeholders can form a collaborative structure among departments, generate synergistic effects, avoid the loss of policy efficiency that arises from functional and task overlap. In the long term, suitable recommendations can be used to establish a specialized support system for urban farming in apartment complexes.

Second, our findings can be utilized to establish a circular participation system for urban farming in apartment complexes. Once the financial, personnel, and technical support issues mentioned above are resolved, the focus will shift to encouraging resident participation.

Given the non-compulsory nature of urban farming, it is crucial to foster resident voluntary involvement. Therefore, the establishment of a circular participation system that encourages ongoing resident participation is necessary.

However, urban farming in apartment complexes is distinct from other forms of urban farming such as school-based, farm/park-based, neighborhood-based, and urban-based farming because it does not allow the sale of produce, involves a larger number of participants, and utilizes rooftop spaces. Therefore, we identified the characteristics of urban farming in apartment complexes and proposed methods for recruiting participants based on a self-distribution system within the community and various leisure programs centered around cultivating crops.

These suggestions can provide support for achieving the sustainable operation and management of urban farming in apartment complexes, which is driven by voluntary participation (Figure 3).

Third, this system can be utilized in establishing a foundational direction for policies related to urban agriculture within apartment complexes. According to the findings of this study, it is necessary to focus on human and social conditions rather than on physical conditions. The categories corresponding to indicators of physical conditions, namely ‘Site Conditions (A),’ ‘Complex Conditions (B),’ and ‘Agricultural Conditions (C),’ all ranked lower. This result implies that the physical conditions of agriculture do not have a significant impact on the success of urban agriculture within apartment complexes. Therefore, strategic policy formulation should prioritize the development of programs that encourage resident participation and activate the community, rather than relying on physical or technical support. Additionally, the development of policies focusing on human and social issues, such as systematic and specialized solutions for conflict resolution among participants, can contribute to the effectiveness of new policies.

Fourth, the four policy directions proposed in the previous section can provide insights useful to both domestic and international practitioners and researchers. The proliferation of high-rise buildings, reduced urban agricultural land, and high-density development is not a problem unique to South Korea. The issue of ensuring the sustainability of urban farming using collective housing is crucial on a global scale when facing these social changes. Although our research scope was limited to high-rise buildings (apartments) of five stories or more in Korea, we believe that our findings can be used as foundational information for policy development in urban environments with high-rise buildings and a high residential density, regardless of the specific country. Therefore, this study can contribute to constructing practical guidelines for both domestic and international practitioners and researchers, aiding them in efficiently formulating policy from planning to project execution, as well as in addressing anticipated issues through research.

We aimed to identify key factors in the initiation of urban farming in apartment complexes and to derive insights regarding what type of policy support is required for sustainable operation. We specifically proposed policy directions informed by the physical and social conditions of apartment complexes required for urban farming. To derive key indicators, three stages of literature review (literature survey, case study, article search) and three stages of expert-opinion collection (in-depth interviews, pilot surveys, AHP questionnaires) were conducted to ensure objectivity. Our findings reflect the current regulations and latest information on administrative support and go beyond the initial objective of simply proposing policy directions for practical implementation.

Most importantly, the results of this study are relevant beyond one-time utilization for policy development and project implementation. They can serve as foundational material for building a public support system to ensure sustainability, setting our study apart from previous research.

6.2. Limitations of the Study

First, we did not comprehensively consider the problems of urban farming in apartment complexes. Apartments are multi-unit dwellings with residents with diverse opinions. In reality, there will be issues such as difficulties in forming a consensus for various reasons (e.g., deterioration of the image of apartment complexes and lower market prices of apartment complexes), disputes over the right to use open spaces, opposition from residents on the floor below, and noise and dust problems. Such issues can be particularly problematic in private apartments with strong claims of ownership. Conflicting opinions should be expected, especially in luxury apartment complexes, where prices are high. Even if dissenting opinions are in the minority, they cannot be ignored. Therefore, it is necessary to take measures to address these issues.

Second, the indicators of “high proportion of women in their 40s or older” (F1) and “low social-activity rate” (F2) are not entirely consistent with the aim of ensuring the sustainability of urban farming in apartment complexes. These indicators focus on the current status of urban farming and can only be used for reference when the government establishes related policies.

Third, resident opinions were not collected in this study. The survey targets in this study were experts in urban farming. However, considering the uniqueness of Korean housing types, it can be assumed that each of the experts has lived in an apartment at least once or understands the associated culture. Residents were excluded based on concerns that they may lack knowledge of urban farming. There were also other concerns that responses would be limited to the apartment where each respondent lived, rather than generalizable to apartment complexes across seven metropolitan cities, which were the targets of this study. In the future, we plan to supplement the findings of this study by selecting a specific target site and conducting a survey of resident perceptions.

Finally, this study focused on apartment complexes in South Korea. The reason for not including international residential communities in the research is as follows. The survey was conducted with Korean experts, and the results were derived based on their responses. It would be challenging to expect accurate survey results if these experts did not have a thorough understanding of the housing types in international residential communities. Additionally, it was anticipated that the level of support for farming activities within residential areas could vary, and the inclusion of such variables was not easily feasible. Nevertheless, despite these considerations, it is hoped that the results of this study can be adopted or partially utilized in international residential communities.