Search Results (36)

Population growth, limited land, and water scarcity threaten urban food security and the environment. Rooftop farming has emerged as a sustainable way to develop urban roofs, reduce food miles, and increase food access. High-density, land- and water-scarce Singapore has prioritized high-tech farms such rooftop hydroponics to improve self-sufficiency and reduce the environmental impacts of importing food. Research indicates rooftop farming has environmental benefits, including lower CO₂ emissions compared to conventional farming, yet we lack a comprehensive understanding of environmental performance. This study applied a life cycle assessment (LCA) to evaluate ComCrop, a pioneer of rooftop hydroponic production in Singapore, using basil as a commonly consumed import. Results showed that 1 kg of basil emitted 0.30 kg of CO₂. A sensitivity analysis showed renewable energy (e.g., solar) could substantially reduce emissions. Results were compared to conventionally grown USA basil (Singapore’s main source), adding transportation to the LCA. Results showed 1 kg of rooftop basil emitted 0.59 kg CO₂ while 8.90 kg CO₂ was emitted in conventional production. Transportation had the greatest impact. We conclude that rooftop hydroponics is the more sustainable production method based on land, water, packaging, and transportation. However, sustainability can be improved with recyclable materials, water nutrient filtration, and renewable energy sources. Full article

Urban gardening, particularly through food-producing green spaces, is increasingly recognized as a key strategy for addressing the complex challenges of climate change, food insecurity, biodiversity loss, and social inequity in African cities. This systematic review synthesizes evidence from 47 peer-reviewed studies across sub-Saharan Africa between 2000–2025 to analyze how urban home gardens, rooftop farms, and agroforestry systems contribute to sustainable urban development. The protocol follows PRISMA guidelines and focuses on (i) plant species selection for ecological resilience, (ii) integration of modern technologies in urban gardens, and (iii) socio-economic benefits to communities. The findings emphasize the ecological multifunctionality of urban gardens, which support services such as pollination, soil fertility, and microclimate regulation. Biodiversity services are shaped by both ecological and socio-economic factors, highlighting the importance of mechanisms such as polyculture, shared labour and management of urban gardens, pollinator activity and socio-economic status, reflected in sub-Saharan urban gardens. Socioeconomically, urban gardening plays a crucial role in enhancing household food security, income generation, and psychosocial resilience, particularly benefiting women and low-income communities. However, barriers exist, including insecure land tenure, water scarcity, weak technical support, and limited policy integration. Although technologies such as climate-smart practices and digital tools for irrigation are emerging, their adoption remains uneven. Research gaps include regional underrepresentation, a lack of longitudinal data, and limited focus on governance and gender dynamics. To unlock urban gardening’s full potential, future research and policy must adopt participatory, equity-driven approaches that bridge ecological knowledge with socio-political realities. Full article

The concept of green cities promotes efficient utilisation of resources, with urban rooftop farms (URFs) being a key initiative involving a series of actions and decisions between stakeholders and the state. The new public governance discourse (NPGD) emphasises this interplay between the state, the market, and civil society to strengthen collaboration and network-driven social innovation and requires a comprehensive understanding of human/stakeholder behaviour. In this study, we explore the connection between organisational rational choice in URF policy development and social innovation. Through a review of the existing literature on URF policies and a case study of Dhaka, Bangladesh, we investigate the development of a comprehensive policy via participation and collaboration, considering the popularity of URFs and the absence of governing mechanisms in Dhaka. The results suggest that, despite the rising popularity of URFs in Dhaka, existing policies and strategies lack clarity. The review findings suggest that a participatory and co-productive approach is optimal for URF policy formulation. This would require active engagement from community members, local governments, and non-governmental organisations and gaining an enhanced understanding of stakeholder dynamics by testing stakeholder salience and co-production theories for successful URF governance. Full article

As global food demand rises, urban agriculture models, such as vertical and terrace farming, have gained traction, especially amid crises like the Ukraine war and COVID-19 pandemic. Climate change remains the most significant threat to global food security. According to the latest FAO analysis, which encompasses assessments from 1990 to 2023, approximately 40% of economic losses resulting from climate-related hazards, including droughts and floods, have impacted the agriculture sector. This has reduced yields, increased production costs, and worsened food insecurity, affecting millions. Urban gardens offer a solution, enhancing food resilience. A systematic PRISMA-based review analyzed studies from Scopus and reports from organizations like the FAO. Over 3329 documents were reviewed. Publications on food resilience grew by 50% in four years, with the US leading with 700 projects. Agricultural and biological sciences dominate research (45%). Urban gardens focus on educating communities about food security and improving food systems. Mobile gardens with portable labs maximize urban spaces, turning rooftops and terraces into productive areas. These initiatives empower communities to grow food, promote nutrition education, and foster social connections. Urban gardens, though not fully sustainable, as they can consume up to 35% more energy per kg of food than optimized traditional farms and generate a 20–40% higher carbon footprint if using imported substrates or plastics, are key for resilient food systems, yielding up to 20 kg/m²/year, reducing transport emissions by 68% (vs. 2400 km supply chains), and using 90% less water than conventional agriculture. Full article

An increasing trend towards the installation of photovoltaic (PV) solar energy generation capacity is driven by several factors including the desire for greater energy independence and, especially, the desire to decarbonize industrial economies. While large ‘solar farms’ can be installed in relatively open areas, urban environments also offer scope for significant energy generation, although the heterogeneous nature of the surface of the urban fabric complicates the task of forming an area-wide view of this potential. In this study, we investigate the potential offered by publicly available airborne LiDAR data, augmented using data from OpenStreetMap (OSM), to estimate rooftop PV generation capacities from individual buildings and regionalized across an entire small city. We focus on the island of Tromsøya in the city of Tromsø, Norway, which is located north (69.6° N) of the Arctic Circle, covers about 13.8 km², and has a population of approximately 42,800. A total of 16,377 buildings were analyzed. Local PV generation potential was estimated between 120 and 180 kWh m⁻² per year for suitable roof areas, with a total estimated generation potential of approximately 200 GWh per year, or approximately 30% of the city’s current total consumption. Regional averages within the city show significant variations in potential energy generation, highlighting the importance of roof orientation and building density, and suggesting that rooftop PV could play a much more substantial role in local energy supply than is commonly assumed at such high latitudes. The analysis method developed here is rapid, relatively simple, and easily adaptable to other locations. Full article

The extreme heat and water scarcity of the desert southwest in the United States of America present significant challenges for growing food crops. However, controlled-environment agriculture offers a promising solution for plant production in these harsh conditions. Glasshouses and plant factories represent advanced but energy-intensive production methods among controlled-environment agriculture techniques. This review aims to comprehensively assess how controlled-environment agriculture can thrive and be sustained in the desert southwest by evaluating the energy efficiency of controlled glasshouses and building-integrated plant factories. The analysis focuses on the efficiency of these systems’ energy and water consumption, mainly using artificial lighting, heating, cooling, ventilation, and water management through various hydroponic techniques. Approximately 50% of operational energy costs in controlled glasshouses are dedicated to cooling, whereas 25–30% of energy expenses in building-integrated plant factories are allocated to artificial lighting. Building-integrated plant factories with aeroponic systems have demonstrated superior water use and energy efficiency compared to controlled glasshouses in desert environments. Integrating photovoltaic solar energy and glass rooftops in building-integrated plant factories can significantly reduce energy costs for urban farming in the desert southwest. Full article

Over the past few decades, a large variety of urban farms and projects have developed in the Global North. Urban agriculture addresses numerous challenges such as producing sustainable fresh food, educating people, and creating new jobs and skills. Urban agriculture is diverse in terms of location (rooftop, basement, underground, parking), activities (food production and/or services), and techniques (from low-tech to high-tech). These projects are created by entrepreneurs because they live in the city, want to change their environment, and promote sustainable practices. Faced with economic and environmental crises, public authorities at different levels and with various orientations reorganize the food system towards local production and consumption; they encourage the development of urban agriculture through a diverse range of policies. These public projects must be economically viable but can be created as socially oriented services based on food production and not only as sites of food production. Our empirical research based on the case studies of two original public urban farms, the Potager du Roi de Versailles and the Cité Maraichère de Romainville, uses the concept of the triple layered business model and highlights their sustainable strategy. Our evaluation of their economic, social, and environmental impacts tends to demonstrate not only their dependence on multiple interlinked public policies but also the justification of significant and recurring public funds for the general interest. Full article

It is evident that, due to population growth, future urbanization and urban growth are inevitable. It is estimated that the food supply demand of future urban centers will grow, which will place an additional burden on the agriculture sector to produce more food. It is projected that securing the food supply chain for future urban centers will be a challenge. Urban agriculture can be regarded as a remedy for possible future challenges that the global food system will face. It might be able to reduce the future burden on the agriculture sector. This research proposes that urban rooftop agriculture, as a subset of urban agriculture, can produce local fresh food in dense urban environments. The principal aim of this research is to suggest a series of design recommendations for architects interested in designing residential buildings capable of rooftop food production. This research attempts to highlight the specific design recommendations and the principal limitations regarding designing residential rooftop farms. To extract the data for developing the proposed design recommendations and limitations, a review of the literature within the fields of urban agriculture, building-integrated agriculture, and horticulture was conducted. Based on the literature review results, this research suggests that the following three types of farming methods can be developed on residential rooftops: (1) open-air rooftop food production, (2) “low-tech” rooftop greenhouses, and (3) “high-tech” rooftop greenhouses. In addition, factors that can be considered principal limitations are suggested. In sum, this research proposes that current and future residential buildings can be designed so that their rooftops are utilized as farms. In this way, such buildings can contribute to delivering local fresh food to current and future metropolitan dwellers. Full article

Increased land use as a result of urbanization is one of the most rapid human-driven causes of biodiversity loss. Urbanization negatively affects human health because of poor nutrition, non-communicable diseases (NCDs) and health problems related to air pollution. Nature-based solutions (NbSs) for sustainable food production in combination with reduced land and water use are essential for the reduction in biodiversity loss, human health and nutrition. This systematic review aims to assess the effects of NbSs that positively contribute to biodiversity on human health and wellbeing in urban settings worldwide. Secondarily, other factors, such as safety, attractiveness, inequity and accessibility, that may have a potential role in the use of NbSs will be evaluated. For the purpose of the FENS conference, only results related to nutrition and food security will be presented. The PRISMA guidelines will be followed. Full-length articles in English language conducted in 2000 and published in 2010 will be included. Both quantitative and qualitative studies are eligible. Due to the diversity of studies, the quality assessment with diverse studies (QuADS) tool will be used for the quality assessment of the studies included. The statistical analysis will depend on the heterogeneity and the feasibility of harmonization of the data. PubMed, Web of Science and Scopus were searched. The initial search yielded 14386 publications. After the removal of duplicates, 8730 titles and abstracts were screened. Currently, 881 full texts out of 2928 have been screened, from which 69 (8%) studies reported outcomes related to human nutrition and food security. Most of the studies took place in urban gardens (61%). Urban farming (25%) and farmers’ markets followed (25%). Vegetation/greenness in cities was considered as an NbS by 6% of the studies. Less studied NbSs were green roofs, general green spaces, urban foraging and urban blue spaces (3% each). Gardening has been shown to be beneficial for the wellbeing and nutrition of various populations. Due to the high land use for the feeding of urban populations, alternative food production techniques without soil use are important. Soil-free rooftop farms and vertical farming could increase the vegetable and fruit production in cities and improve the diet quality of citizens. Full article

Rooftop greenhouse-type smart farms are a promising solution to the climate and food crises because they can utilize waste heat and CO₂ from buildings for plant growth and supply fresh produce to urban areas at a low price. However, legal and structural constraints make it difficult to expand existing rooftops to accommodate smart farms, and standardized glass greenhouses are often installed as is, which may not be the most efficient or eco-friendly approach. The purpose of this study is to present a plan for integrating eco-friendly technologies between buildings and smart farms. In the study, 214 eco-friendly and smart farm cases were collected, and a database was built from the perspective of the environment and eco-friendly technology for plant growth. Thirty experts from architects, professors, and greenhouse installation companies were evaluated to determine which eco-friendly technologies can be applied to smart farms. From a building integration perspective, eco-friendly technologies applicable to smart farms were derived from a plant growth perspective. Based on the derived eco-friendly elements, it can be used in planning a rooftop greenhouse-type smart farm. Full article

Considering the rising concern over climate change and the need for local food security, productive blue-green roofs (PBGR) can be an effective solution to mitigate many relevant environmental issues. However, their cost of operation is high because they are intensive, and an economical operation and maintenance approach will render them as more viable alternative. Low-cost sensors with the Internet of Things can provide reliable solutions to the real-time management and distributed monitoring of such roofs through monitoring the plant as well soil conditions. This research assesses the extent to which a low-cost image sensor can be deployed to perform continuous, automated monitoring of a urban rooftop farm as a PBGR and evaluates the thermal performance of the roof for additional crops. An RGB-depth image sensor was used in this study to monitor crop growth. Images collected from weekly scans were processed by segmentation to estimate the plant heights of three crops species. The devised technique performed well for leafy and tall stem plants like okra, and the correlation between the estimated and observed growth characteristics was acceptable. For smaller plants, bright light and shadow considerably influenced the image quality, decreasing the precision. Six other crop species were monitored using a wireless sensor network to investigate how different crop varieties respond in terms of thermal performance. Celery, snow peas, and potato were measured with maximum daily cooling records, while beet and zucchini showed sound cooling effects in terms of mean daily cooling. Full article

This paper responds to the research question, “can urban farming in Nepal help create sustainable cities?” Especially after the COVID-19 pandemic, urban residents have begun to realize that food transported from long distances is not always reliable. Urban farming can help produce fresh food locally and help urban residents become self-reliant by engaging in healthy eating habits and practicing sustainable agricultural techniques in food-desert areas, while creating a positive impact on the environment through regenerative agricultural methods. In doing so, urban farms can help the growers save on food expenditures and even earn some additional income, while also improving air quality and minimizing the effects of urban heat islands. This practice also helps reduce greenhouse gases through plant carbon use efficiency (CUE), as vegetation carbon dynamics (VCD) can be adjusted while supporting the circular economy. As urban lands command higher prices than agricultural land, urban farming usually happens on residential yards, roofs, balconies, community gardens, and dedicated areas in public parks. Rainwater harvesting and redirecting can help irrigate urban farms, which can be part of rain gardens. The national census of 2021 identified that 66% of Nepal’s population lives in urban areas. However, the World Bank (2018) showed that only 21 of Nepal’s population was projected to live in urban areas in 2021. It is not debatable that the urbanization process in Nepal is on the rise. Thus, urban agriculture can play an important role in supplementing residents’ food needs. Many cities in Nepal have already successfully adapted to urban farming wherein residents grow food on their building sites, balconies, and rooftop, often growing plants in pots, vases, and other types of containers. The UN-Habitat, with the support of the European Union and local agencies, published a rooftop farming training manual (2014), showing the feasibility of urban farming in Nepal. This paper discusses how public-private partnership (PPP) can promote urban agriculture and make the process more effective and attractive to urban-farming households. It also analyzes how a PPP approach also facilitates the use of better technology, advisory support, and use of research extension activities. This paper draws on a literature review, uses remote-sensing imagery data and data from National Census Nepal 2021, and the authors’ professional experiences related to best practices in the areas to analyze the benefits and challenges related to urban farming both in Nepal and Arizona, USA. The paper provides recommendations for Nepali cities to maximize the benefit provided by urban farming. It is expected to be useful to Nepali policymakers, government agencies, and nonprofit organizations which promote sustainability, and organic farming with a sustainable supply chain. Full article

The scarcity of land resources and food security challenges have prompted more effective uses of the rooftop as well as façade spaces in the urban city of Singapore. Urban rooftop spaces are used for mechanical and electrical (M&E) amenities such as air-conditioning cooling units and water tanks, so the spacious span of the roof area on HDB flats in Singapore is not available. Urban-metabolic farming modules (UmFm) built on 1.5 to 2 m terrace-step terrains have been modelled using BIM Revit to mimic such constraints in rooftop spaces. CFD simulation was conducted for the structure with consideration of the prevailing wind directions at different months of the year. The airflow with the inclusion of mesh netting and varying tiltings of the polycarbonate side façade was simulated to understand their impact on airflow in the growth envelope of the UmFm units under different prevailing wind directions. The amount of solar irradiance received by the crops at different heights in the UmFm due to the sun’s path, and shading of crops grown on the A-frame, was studied using Climate Studio. A comparative verification was done with a scaffold modular unit mounted with temperature, humidity, airflow, and Photosynthesis Photon Flux Density (PPFD) sensors. The digital model of the UmFm unit enables a prior assessment of site feasibility before actual physical implementation on an existing rooftop. It also facilitates plug and play for the UmFm unit to generate an eco-resilient farmscape for an urban city. Full article

Agrivoltaic systems have the potential to maximize the usefulness of spaces in building rooftops. Urban farming systems improve the microclimatic conditions, which are beneficial to solar photovoltaic (PV) systems, as they lower the operating temperatures, resulting in a higher operating efficiency. Microclimate simulations by means of ENVI-met simulation showed that between 0800 h and 1800 h, PV temperatures in the plot that has crops below the PV system were on average lower by 2.83 °C and 0.71 °C as compared without crops on a typical sunny and cloudy day, respectively. Hence, we may see PV efficiency performance improvement of 1.13–1.42% and 0.28–0.35% on a sunny day and cloudy day, respectively. Data collected from a physical prototype of an agrivoltaic system suggested that evaporative cooling was responsible for the reduction in ambient temperatures. The presence of crops growing underneath the PV canopy resulted in the agrivoltaic prototype generating between 3.05 and 3.2% more energy over the day as compared to a control system with no crops underneath. Full article

Conventional green roofs have been widely accepted as a climate change adaptation strategy. However, little is known about the potential of blue–green roofs and rooftop farms to control urban stormwater and improve microclimates. This study evaluates a farmed blue–green roof’s hydrologic and thermal performance over an entire growing season in Toronto, Ontario, Canada. The runoff discharge from three plots planted with various crops was monitored. The substrate and air temperatures at two elevations of different cultivated and self-sowing plant species were collected and compared to a control roof. Results indicate that planting and harvesting activities impacted the hydrologic performance. Mean values for retention ranged from 85–88%, peak attenuation ranged from 82–85%, and peak delay ranged from 7.7 to 8 h. At the lower elevation, the mean air temperature difference above okra, tobacco, and beet was 2.5 °C, whereas, above squash, potato, and milkweed, it was 1.4 °C. Maximum and moderate air-cooling effects were observed in the afternoon and evening, but a warming effect was observed in the early morning. Farmed blue–green roof evaluated in this study provides a runoff control and microclimate improvement comparable to or better than conventional green roofs, in addition to other benefits such as improving food security. Full article