Urban economic systems extend beyond city boundaries through complex transaction networks that include workers, raw materials, and food. However, consistent with urban–rural linkage theory, relationships are understood at macro levels, yet the household-level mechanisms through which these spillovers integrate rural settlements remain underexplored, particularly in developing-country contexts. Therefore, this study investigates the household transaction mechanisms linking rural economies to urban systems with the aim of understanding whether rural households connected to nearby towns operate as economically embedded extensions of urban systems rather than as isolated agrarian units. Two hypotheses were tested: urban economic spillovers are transmitted through interrelated employment, market exchange, and credit networks; and households with stronger urban-linked employment exhibit different financial conditions and labour allocation patterns compared to less connected households. Primary data were collected with structured questionnaires via a field survey. A sample of 100 was selected through stratified random sampling from 802 households in a rural settlement functionally connected to nearby urban centers. Descriptive statistics were employed to illustrate transaction patterns. A binary logistic regression model evaluated household financial status as the dependent variable, using employment characteristics as key explanatory variables. The Mann–Whitney U test assessed employment involvement both within and beyond the local rural economy. The findings indicated that agricultural output remains the primary means of livelihood (65%), with the majority targeted at urban markets. Employment trends demonstrated significant dependence on urban economic frameworks, with 31.2% of household heads working as plantation laborers, 25% as service providers, and 6% in manufacturing. Observations included formal and informal transaction categories, such as reciprocal labor exchange (50%), credit-driven purchases (24%), and formal borrowing from banks (10%). The research reveals micro-level pathways for spillovers, enhancing understanding of urban economic systems and guiding cohesive urban and regional planning to strengthen economic resilience and support sustainable urban–rural growth.

Introduction

Digital transformation of the construction sector demands trustworthy, interoperable, and economically sustainable mechanisms for managing building‑related data and services. The Horizon-Europe project BUILDCHAIN addresses this need by extending the Digital Building Logbook (DBL) with Decentralized Knowledge Graphs (DKGs), Decentralized Oracle Networks (DONs), and token‑enabled business models to support continuous, verifiable, and machine‑actionable building‑lifecycle documentation.

Methods

BUILDCHAIN ecosystem tools and applications operate within a unified architecture supporting discoverability, access control and monetization. Datasets are transformed into Knowledge Assets (KAs), semantically linked with the DKGs, validated within the DONs by using a reputation‑based mechanism, and stored immutably, ensuring that data providers can confidently monetize their assets. Smart contracts, including Service Level Agreements (SLAs), manage access, payments, and service execution, supporting subscription‑based, usage‑based, or hybrid pricing. A tokenized economic layer enables seamless transactions, access control, automated regulatory compliance and verifiable ownership of digital assets. Economic sustainability is evaluated through multi-actor Business Model Canvases and Value Network mapping, identifying the cost structures and value propositions of urban economy chain stakeholders, demonstrating a win–win sustainable ecosystem.

Results

Three interconnected markets are suppoprted: a service marketplace for BUILDCHAIN tools, a data marketplace for monetizing building‑related datasets, and a side market enabling third‑party applications to integrate with the DBL, DONs, and Building Information Modeling (BIM) ecosystem. Digital wallets and token‑based remuneration streamline partner compensation, enabling transparent, traceable economic flows. The architecture’s viability is shown through a representative scenario where a building‑energy‑efficiency tool uses DBL data and DON weather feeds to optimize HVAC operation. Results demonstrate stakeholder benefits and building‑stock improvements that, when scaled, allow buildings to act as flexible grid resources and enhance city‑wide resource‑management efficiency.

Conclusions

BUILDCHAIN introduces a scalable, tokenized, Oracle‑enhanced business model that transforms DBLs from static repositories into dynamic economic infrastructures, enabling new forms of data monetization, service innovation, and cross‑sector value creation in built environments.

Urbanization activities, such as eutrophication, pollution and runoff, lead to changes by negatively impacting and reducing the diversity of the microbiome. Urban blue spaces are an integral part of cities; several communities depend on urban water bodies for their livelihood and survival and are heavily affected by rapid urbanization. They play a crucial role in maintaining both human and ecological health at the population level. Quantifying these changes is important for sustainable urban planning.

Using extensive keywords targeting urban blue spaces, such as microbiome and urbanization, we retrieved 1060 papers from two databases and one search engine based on our inclusion criteria of primary data sources for microbiome of aquatic freshwater bodies. Out of 1060, we identified 105 eligible papers after multiple screening rounds. We analyzed these manuscripts from 2000 to 2025 that examined changes in the functional traits, such as antimicrobial resistance (AMR) and nitrogen cycling of the microbiome. Data were extracted by a thematic analysis followed by a narrative synthesis on specific functional traits. This systematic review presents a comprehensive analysis of the changes and challenges caused by urbanization.

Our results indicate that urbanization leads to reduced bacterial diversity of urban water bodies, specifically an increase in Proteobacteria, Cyanobacteria and Coliform bacteria. A significant increase in AMR genes in the water bodies increases the risk of infection by a resistant pathogen.

Microbiome studies on water bodies are indicators for the extent of spread of AMR among pathogens, animals, and humans. The release of antimicrobial compounds into water bodies acts as a driving force for microbial resistance and leads to the emergence of resistant pathogens. Understanding changes in the microbiome is crucial to various blue space functions such as nutrient cycling, organic matter decomposition, and water purification. These insights help inform public health strategies and sustainable urban planning.

The transition to low-carbon energy systems is a central objective of the European Union and a key requirement for sustainable economic and environmental development. Portugal has historically shown a high dependence on imported fossil fuels, which has affected energy security, carbon emissions, and economic stability. European climate policy has promoted renewable energy expansion, electrification, and efficiency improvements, but significant structural differences remain among member states in the effectiveness of decarbonization strategies.

This study applies a quantitative panel data approach to analyse the evolution of the Portuguese energy system in comparison with selected European Union countries over the period 1990–2025. The empirical framework is based on official energy and environmental indicators, including greenhouse gas emissions, carbon intensity, energy intensity of GDP, renewable energy shares, and external energy dependence. Data were obtained from national emission inventories, European statistical databases, and energy policy reports. Time-series analysis, cross-country benchmarking, and fixed-effects panel estimation were used to evaluate the relationship between renewable energy expansion, efficiency improvements, and emission reduction, while controlling for structural shocks related to economic crises and energy market volatility.

The results indicate that increases in renewable energy shares and improvements in energy efficiency are associated with significant reductions in carbon intensity. Portugal shows substantial progress in emission reduction and renewable electricity generation, but still presents higher external energy dependence compared with more efficient European economies. Countries with stronger policy integration and technological development demonstrate better environmental performance and greater resilience to energy shocks.

The findings confirm that the effectiveness of decarbonization policies depends on the combined effect of renewable energy expansion, efficiency improvements, and technological modernization. Strengthening these factors is essential for achieving long-term sustainability goals and for building resilient economic and urban systems in the European Union.

Small-scale water architecture with closed-circuit systems has become an integral component of contemporary public spaces, contributing to their aesthetic quality, recreational value, and social attractiveness. Elements such as fountains, interactive water features, and ornamental basins are increasingly important in urban design strategies aimed at improving the quality of life in cities. However, alongside these benefits, closed-circuit water installations generate a range of technical and sanitary challenges that require careful consideration.

Water circulating in a closed system is continuously exposed to environmental factors such as temperature fluctuations, airborne pollutants, organic matter, and intense human interaction. These conditions significantly increase the risk of biological and chemical contamination, including the development of pathogenic microorganisms and the accumulation of harmful substances. In public spaces with unrestricted access, these risks are further intensified by direct user contact, particularly in interactive installations designed for play and recreation.

A major challenge in this context is the lack of clear, comprehensive legal regulations governing the design, operation, and maintenance of closed-circuit water features in public spaces. Existing standards are often fragmented, ambiguous, or adapted from swimming pool or drinking water regulations, which do not fully address the specific characteristics of small urban water installations. This regulatory gap complicates effective supervision, quality control, and responsibility allocation among stakeholders.

The analysis presented in this research highlights the urgent need to develop coherent guidelines that integrate technical, sanitary, and legal perspectives. Such guidelines should encompass system design, water treatment technologies, monitoring procedures, and operational practices. Only through an interdisciplinary, integrated approach can closed-circuit water installations operate safely, sustainably, and responsibly within the urban public realm.

Cities are increasingly turning to private investment to fund public infrastructure by treating urban land as a financial resource through Land Value Capture (LVC) tools. In India, LVC has gained attention in recent years, with national and state planning frameworks encouraging cities to use land-based financing methods to support infrastructure development and urban growth. Although LVC is often seen as an innovative solution to funding challenges, its growing use raises important questions about economic resilience, governance, and the long-term sustainability of urban resource management.

This paper uses Ahmedabad as a case study to examine the Sale of Development Rights (SDR), an LVC tool included in the city’s Development Plan, and explores how urban land is turned into funds for public infrastructure financing. By examining legal guidelines and municipal budget data, it tracks the increasing role of SDR in city revenues and evaluates its impact on urban financial stability and planning goals.

This study shows that relying more on SDR can expose cities to financial risks associated with real estate market cycles and wider economic trends. This reliance may limit municipal independence and affect development choices as funding for infrastructure becomes closely linked to private market forces. By turning development rights into financial assets, LVC tools change how urban land is governed as a public resource, impacting fairness, spatial planning, and equitable access to urban infrastructure.

This paper concludes that while LVC can effectively add to municipal revenues, excessive dependence on private investment carries significant financial risks. It contributes to debates on how cities can balance growth-oriented financing mechanisms with economic stability and equitable resource management.

The rapid deployment of Urban Digital Twins (UDTs) and algorithmic decision-making systems promises enhanced efficiency in urban resource management. However, this digitalization often generates severe socio-technical frictions, primarily manifesting as algorithmic black boxes and vendor lock-in by major tech giants. Such technological exclusivity inherently restricts inclusive economic participation and exacerbates rent-seeking risks in public resource allocation.

This study introduces the concept of "Institutional Middleware"—a standardized regulatory and technical buffer comprising interoperability clauses (e.g., MIMs), open APIs, and algorithmic transparency requirements—and empirically tests its causal effect on mitigating rent-seeking behaviors in smart city procurement. Utilizing a comprehensive micro-dataset from the EU Tenders Electronic Daily (TED) database (2016–2025), we focus on high-complexity IT and software procurement contracts. Methodologically, we apply Natural Language Processing (NLP) to extract the intensity of institutional middleware clauses from unstructured contract notices. Subsequently, a high-dimensional two-way fixed effects model is employed to evaluate the impact of these clauses on the "single-bidder rate" (a globally recognized proxy for corruption and lock-in risks) and the market entry success of Small and Medium-sized Enterprises (SMEs).

Preliminary and expected results indicate that public digital contracts embedding strong institutional middleware significantly reduce single-bidder anomalies and increase SME participation. The findings suggest that interoperability and open standards serve not merely as technical specifications, but as crucial ex-ante anti-corruption mechanisms. By standardizing compliance and dismantling technological monopolies, institutional middleware effectively balances the efficiency–legitimacy trade-off, fostering a more inclusive and resilient urban digital economy during the twin transition.

The application of renewable energy in buildings, particularly solar radiation (e.g., passive thermal solutions), supports more energy-sustainable city development by enabling buildings with lower energy consumption. This work will analyse the influence of external environmental variables, such as air temperature, air relative humidity, air velocity, carbon dioxide concentration, solar radiation, and other factors, on the assessment of comfort levels, namely the thermal comfort and indoor air quality that the occupants are subjected to in city buildings, using renewable energies.

The work will be developed numerically, using numerical software that simulates the thermal response of buildings. The building, equipped with internal greenhouses, will be analysed. The study examines the evolution of air temperature, building surface temperatures, air relative humidity, air velocity, carbon dioxide concentration, and direct and diffuse solar radiation in outdoor and indoor environments throughout the day. The level of thermal comfort will be assessed using the PMV index. The level of indoor air quality will be evaluated based on the carbon dioxide concentration to which occupants are subjected. The study was conducted in winter conditions and in a Mediterranean environment.

The internal greenhouse, for example, with its hall entrance or covered walkways, is protected by glass facing east, west, and mainly south. The greenhouse stores energy inside the buildings. This energy is transported to cold spaces, such as interior spaces or those facing north, to improve thermal comfort. The renewable airflow rate during transport from the greenhouse to the cold spaces ensures acceptable indoor air quality in both spaces.

The results indicate that the south-facing spaces, equipped with internal greenhouses, are thermally comfortable, and the airflow rate transported to the north-facing spaces, used as cold spaces, also ensures thermal comfort. The proposed solution ensures an airflow rate that guarantees good indoor air quality conditions in all spaces.

The urban informal economy in the Global South is normally associated with negative connotations, such as illegality and transience. As a result, many regulations at the national and local levels appear to focus on how to control or minimise the expansion of this sector. Largely missing from many of these interventions is a proper understanding of the socio-spatial context that creates and perpetuates this economy. This paper thus seeks to unpack the nuances associated with the urban informal economy. Based on a case study of Namibia, this study argues that, rather than being a nuisance in the urban landscape, the informal economy constitutes a localised form of privatism. This is evident in the entrepreneurial bent and creative ethos that define the activities of these traders. Moreover, the diversity of goods and services provided is noteworthy. There is also an indigenous element to the way business is conducted, as evident in the socio-spatial set-up of these operations. This economy emphasises sole proprietorships, partnerships and cooperatives. While formal workers’ rights are not necessarily enforced, they are informally present through familial and kinship ties. The informal economy constitutes a source of livelihood for many, thus reducing pressure on the government to provide jobs. Contrary to the argument that this endeavour constitutes old forms of work, it embodies the changing nature of work through innovation, self-organisation and social networking. This paper contributes to the existing literature by articulating an economic justice framework for protecting the rights of traders and workers in the urban informal economy.

Regulatory frameworks, encompassing policy, land use, and financial instruments, fundamentally shape urban land markets and development trajectories. In rapidly urbanizing nations like India, these frameworks often struggle to balance the need for orderly growth with market efficiency. This study aims to analyze the evolution of diverse regulatory frameworks and their specific impacts on urban and peripheral land development in India, utilizing international benchmarks to highlight unique challenges and areas of convergence. The research employs a systematic scoping review to map and categorize multidisciplinary regulatory frameworks across urban economics, planning, and public policy. A structured selection process was conducted, initially identifying over 2,000 records. Through rigorous filtering, the pool was refined to 58 relevant studies, which were then thematically analyzed under categories of theory, case studies, and specific regulatory types. Findings indicate that while market-based land allocation enhances urban productivity compared to administrative systems, rigid land use regulations such as strict Floor Area Ratio (FAR) limits and Urban Growth Boundaries (UGBs) often lead to significant housing price inflation and welfare losses. For example, Mumbai’s uniform and restrictive FSI policy has historically constrained floor space supply, driving prices upward and forcing a majority of the population into informal settlements. Furthermore, case studies from the UK and India demonstrate that containment policies frequently fail when overridden by fiscal interests, leading to uncontrolled sprawl. While Indian reforms like RERA (2016) and LARR (2013) have improved transparency and compensation, enforcement disparities continue to undermine market dynamism. The study concludes that although regulations are essential for guiding sustainable growth, overly rigid or outdated structures often induce unintended consequences, including market distortions and increased informality. A nuanced, context-specific approach is required to balance private property rights with public interests. Future urban resilience depends on integrating risk assessments into zoning and improving coordination between state-led regulations and market-led development.