This section examines the situation of Akure, existing research on green construction practices, gaps in the existing literature, and the relationship between green construction and the Sustainable Development Goals (SDGs).
2.1. Contextualizing the Situation of Akure, Ondo State
While southwestern Nigeria, encompassing states like Lagos, Ogun, Oyo, Osun, Ekiti, and Ondo, experiences a predictable cycle of wet and dry seasons with a tropical climate [
8], climate change has disrupted these patterns. These regions now face more frequent and intense rainfall events, leading to widespread and devastating floods that not only cause significant damage to infrastructure but also pose serious risks to public health and safety [
5]. Akure, the capital of Ondo State, serves as a prime example of this growing threat. In 2019, intense flooding caused the Ogbese River to overflow its banks, wreaking havoc in the Ayede Ogbese area of the Akure North Local Government Area [
7]. Also, major streets and neighborhoods across Akure were submerged in July of last year, with areas like Oja Oba, Ondo Road, Isikan, Oyemekun, Alagbaka, and Ijoka being particularly hard hit. According to ref. [
6], several houses were completely submerged by the floodwaters and numerous families were displaced, resulting in extensive property damage and significant economic losses. This pattern of extreme weather events continued into 2024. The state capital experienced a harrowing episode earlier this year as heavy rains triggered severe flooding in the Oke-Ogba/Awule/Adebowale area [
6]. The floodwaters ravaged homes and properties, displacing residents and causing millions of naira in damages [
9]. These flooding events in Akure underscore the vulnerabilities in the city’s infrastructure and the pressing need for timely and responsive efforts to mitigate such risks. While improved drainage infrastructure plays a crucial role, a shift towards green construction policies and programs can be instrumental in mitigating the impacts of flooding and building a more resilient urban environment [
10]. In the context of this study, green construction policies and programs refer to regulatory frameworks, incentives and initiatives aimed at promoting sustainable building practices.
2.2. Overview of Green Construction Policies
Having understood some of the flooding issues plaguing Akure, and indeed across the world, in the face of climate change, several green construction policies and programs have emerged. One such policy gaining momentum is building codes and standards which provide a framework for ensuring that buildings are safe, sustainable, and energy efficient [
11]. The regulations often include guidelines on energy use, water conservation, indoor environmental quality, and the use of sustainable materials. Research has shown that stringent building codes can significantly reduce energy consumption and greenhouse gas emissions. According to ref. [
12], implementing energy-efficient building codes can reduce energy consumption in buildings by up to 30% compared to buildings without such standards. Green certification requirements, such as Leadership in Energy and Environmental Design (LEED) and Building Research Establishment Environmental Assessment Method (BREEAM), provide a standardized approach to measuring a building’s environmental performance. These certifications encourage builders and developers to adopt sustainable practices [
13]. However, ref. [
14] notes that the primary challenge with green certification requirements is the cost and complexity associated with obtaining certification. According to the study, small developers may find it difficult to meet the stringent criteria due to financial or technical constraints. Thus, there is a need for continuous monitoring and recertification to ensure that buildings maintain their green status over time [
15]. In Nigeria, the government has developed national standards and guidelines to encourage sustainable building practices. The Nigerian Building Code includes provisions on energy efficiency, water conservation, and environmental sustainability. Additionally, the Energy Efficiency Building Code (EEBC), developed by the Federal Ministry of Power, Works, and Housing in collaboration with the Nigerian Energy Support Programme (NESP), provides mandatory energy efficiency guidelines for residential, commercial, and public buildings. The Nigeria Green Building Council (NGBC) also promotes green certification frameworks that align with local environmental conditions and energy demands. Furthermore, regulatory bodies such as the National Environmental Standards and Regulations Enforcement Agency (NESREA) set environmental compliance standards for construction activities to mitigate ecological degradation [
5,
6,
16].
Zoning regulations and land use planning are also essential for promoting sustainable development and reducing the environmental impact of construction activities. According to ref. [
17], these policies control the use of land in a way that supports green building practices, such as promoting higher-density developments, preserving green spaces, and reducing urban sprawl. The research conducted in ref. [
18] found that cities with comprehensive land use planning and zoning regulations have lower per capita energy consumption and reduced greenhouse gas emissions. Also, the promotion of mixed-use developments and transit-oriented designs can significantly reduce the need for private vehicle use, further contributing to sustainability goals [
19]. Nevertheless, implementing effective zoning regulations requires careful planning and collaboration among various stakeholders, including government agencies, developers, and the community [
17]. Likewise, forest protection and restoration initiatives, equally critical as they aim to preserve existing forests and restore degraded ones, are crucial for maintaining biodiversity, sequestering carbon, and providing sustainable construction materials [
20]. However, the success of forest protection and restoration in developing countries hinges on tackling challenges like illegal logging, agricultural land conversion, and weak enforcement. As ref. [
19] highlights, engaging local communities is crucial for long-term sustainability as this not only helps in preserving forests but also provides socio-economic benefits to the communities involved [
16].
Streamlining the permitting process for green construction projects is another critical green construction policy. This can significantly reduce delays and costs associated with building approvals, encouraging developers to adopt sustainable practices by making the process easier and more cost-effective [
18]. The main challenge in streamlining the permitting process is ensuring that the expedited procedures do not compromise the quality and safety of construction [
14]. Therefore, adequate training and resources for permitting officials are necessary to maintain standards while facilitating faster approvals [
15]. Similarly, public procurement streamlining, which involves simplifying and optimizing the processes through which government agencies purchase goods and services, can significantly enhance the adoption of green building practices [
21]. Moreover, these policies often result in long-term cost savings for public agencies due to lower operational and maintenance costs [
16]. Additionally, studies have indicated that international trade policies that reduce tariffs and non-tariff barriers on green products can enhance the adoption of sustainable construction practices. For example, the authors of ref. [
22] found that lowering trade barriers for renewable energy technologies led to increased deployment of these technologies worldwide. Similarly, trade policies that support the import of energy-efficient building materials can reduce the carbon footprint of construction projects [
23]. Green mortgage programs further incentivize green construction by offering favorable financing options for energy-efficient and sustainable buildings [
24]. These programs can include lower interest rates, higher loan amounts, and extended repayment terms, making it easier for homeowners and developers to invest in sustainable practices [
25].
Furthermore, landscape restoration programs are essential for creating sustainable environments that support green construction practices [
16]. These programs aim to rehabilitate degraded lands and ecosystems, improving biodiversity, water quality, and carbon sequestration. The authors of ref. [
26] suggest that landscape restoration can also improve soil health and enhance water retention, contributing to more resilient ecosystems crucial for sustainable development. However, implementing these programs requires substantial investment, long-term commitment, and support of local communities. Thus, there is a need for comprehensive planning and coordination among various stakeholders to address the complex ecological, social, and economic factors involved in landscape restoration. In the same vein, climate change adaptation strategies proactively enhance the resilience of buildings and infrastructure to the escalating threats of climate change, including rising temperatures, extreme weather, and sea-level rise [
27]. These forward-thinking approaches are critical for ensuring the long-term sustainability of construction projects. As expressed in ref. [
28], every dollar invested in resilience and adaptation measures saves four dollars in future disaster recovery costs. Offering incentives for retrofitting existing buildings can significantly improve their energy efficiency and environmental performance, even for older structures. As ref. [
12] found, such green construction programs can also enhance indoor air quality and occupant comfort, ultimately leading to higher property values and lower operating costs. Also, financial incentives and rebates can take various forms, including tax credits, grants, and low-interest loans, aimed at offsetting the higher initial costs associated with sustainable building practices [
15].
Table 2 provides a summary of the green construction policies and programs utilized for further analysis.
2.4. Green Construction and the Sustainable Development Goals (SDGs)
The United Nations’ Sustainable Development Goals (SDGs) serve as a global framework for addressing critical environmental, social, and economic challenges. Among the 17 goals, several are directly relevant to sustainable construction practices, particularly SDG 11 (Sustainable Cities and Communities), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action). These goals emphasize the importance of adopting environmentally responsible practices, enhancing resilience against climate-related disasters, and fostering resource-efficient construction methodologies. Green construction policies, such as energy-efficient building codes, green certifications, and land use planning, align with the objectives of SDG 11 by promoting sustainable urban development and reducing environmental impacts. Also, the implementation of energy-efficient building codes can significantly lower greenhouse gas emissions, supporting the global climate action agenda of SDG 13. Similarly, the promotion of circular economy principles through the use of recycled materials and waste reduction in construction directly aligns with SDG 12, fostering responsible production and consumption patterns. Overall, this study contributes to the discourse on SDGs by exploring how green construction practices in Akure, Ondo State, can support the achievement of these global goals. It also aims to bridge the gap between global SDG priorities and their local application, providing insights into the specific challenges and opportunities for integrating sustainable development principles into Nigeria’s construction sector.