Public Policies for the Design and Implementation of Sustainable Cities

Abstract

The main aim of this study is to propose a series of recommendations to public administrations for the development of economic policies that promote the contribution of the construction and civil engineering sectors to the design and implementation of sustainable cities. The study was conducted on the island of Tenerife. Documentary research and in-depth interviews with key agents were used as qualitative techniques. The recommendations are described in a portfolio of action policies grouped into three action areas: macroeconomic demand policies, regulation and reform policies, promotion and support policies, and governance and collaboration policies. Among other results, it is worth mentioning that there is a European support framework for economic policies to promote this transformation, but it is necessary to apply them whilst taking into account the environment where they are applied. Existing measures need to be evaluated to improve them and/or replace them with those mentioned by the key agents, all within an action plan that facilitates their implementation. Building sustainable cities requires public–private collaboration, institutional efficiency, and the socio-environmentally responsible performance of companies in the sector.

1. Introduction

Urban conditions determined by the quality of life and the environment in which people live in cities are undergoing a radical transformation, with the consolidation of new urban spaces and new forms of urbanization [1]. The traditional development model, focused on unlimited urban growth, is being discarded in order to build a model that emphasizes the regeneration of cities with public spaces and quality public services. To do this, it is important to analyze the possible gaps existing in the interrelationship of urban policies and governance from the perspective of the sustainable production of urban spaces [2].

The agents of the construction sector consider that the best way to contribute to designing sustainable and accessible cities is to reconcile the energy efficiency needs of the building stock, the construction of sustainable buildings, and the rehabilitation of old buildings, both public and private, with the needs of civil engineering works. This requires effective public–private collaboration, with public agents taking the initiative to develop a reactivation and transformation plan with measures that align with the objectives established by the European Union (EU) on this matter.

The development of economic policies aimed at the design and implementation of sustainable cities should be approached from a systemic economic policy approach so that the set of actions and instruments applied have a comprehensive effect on achieving its objectives [3]. The main instrumental policies that particularly affect the construction sector require a common strategy of interaction and coordination. Sectoral policies are highly relevant in economic policy, and the construction sector plays a key role in them because it contributes to accelerating economic growth, with its added value and capacity to create employment and promote responsible consumption and investment having significant weight.

This sector has a powerful pull on industry and production in general, producing backward chains that prompt local producers to demand inputs that were previously imported from local industry, and forward chains that favor new investments in products that were previously unavailable or extremely expensive. These links trigger a sequence of investments stemming from an initial one, strengthening local value chains. By fostering domestic production, reducing reliance on imports, and encouraging innovation, this process supports more resilient and inclusive local economies—a key factor in building sustainable cities that are economically vibrant, environmentally responsible, and socially equitable [4].

However, the existing literature tends to analyze urban policies, the role of the construction sector, and territorial governance separately, leading to fragmentation of knowledge and making it difficult to develop integrated strategies. Few studies address these dimensions jointly, especially from a perspective that combines economic policy design, institutional arrangements, and multilevel governance to foster sustainable urban planning. This research gap highlights the need to develop more comprehensive approaches that offer concrete proposals for coordinated and effective governance.

The design of a global economic policy action strategy in the construction sector that takes into account socially responsible actions focuses on the following five major areas: optimizing the regulatory framework, promoting training and technical assistance, encouraging the exchange of practical experiences, improving financing, and raising awareness. All of this is within a sustainable framework of socio-environmental cohesion. Thus, a city formally built in these terms has positive effects on sustainable development and society in general. Long-term planning involves having quality information to analyze the territory and evaluate actions to improve or change them in the new proposal. Effective management is therefore required to provide transport infrastructure, social facilities, and essential services, with the promotion and renovation of sustainable housing being priority actions. Similarly, it is necessary to generate trust and legal stability to promote investment. Economic policies implemented by public administrations contribute to overcoming the barriers faced by the construction sector, but governance is fragmented across multiple levels [5,6,7]. This fragmentation can affect the implementation of measures and their effects, making it necessary for planning across different public administrations to be coordinated [8,9].

Against this backdrop, the novelty of this article lies in its holistic and action-oriented approach, which articulates economic, urban, and institutional dimensions to provide practical policy recommendations for public administrations. Based on these premises, the main objective of this project is to propose a series of recommendations to public administrations for the development of economic policies that promotes the contribution of the construction and civil engineering sectors to the design and implementation of sustainable cities.

The main contributions of this article are as follows: (1) the identification of concrete economic policy measures across five key areas; (2) the development of an analytical framework to classify actions by their nature (fiscal, regulatory, promotional, governance-related, etc.); and (3) the analysis of the barriers faced by different levels of government in implementing these policies.

The research questions focus on reflecting on the state of the art, the type of actions necessary to achieve this objective in the coming years, classified according to fiscal/budgetary policies, regulation and reform policies, promotion and support policies, and governance and collaboration policies, as well as the limitations that may be found in implementing them. The Section 2 sets out a theoretical framework focused on the paradigm change required by companies in the sector and public administrations. The Section 3 describes the methodology used in the study. The Section 4 presents the proposal for a portfolio of action policies, responding to the aim of the work and the research questions. The Section 5 presents the discussion, and the Section 6 contains the conclusions, limitations of the study and future lines of research.

2. The Paradigm Changes for Companies in the Construction Sector and Public Administrations

The difference between a sustainable construction and one that is not lies in choosing the right materials and construction processes which have an impact on the sustainable development of the urban environment. When this extends to an entire city, it is necessary to consider planning, social behavior, behavioral habits, and changes in building use to extend their useful life. This requires analyzing the entire life cycle of buildings and infrastructure, from the architectural design and acquiring raw materials until they return to the environment in the form of waste. Sustainable construction is not only about creating habitable spaces, but also about influencing how these spaces should be used [1,2].

The most sustainable construction model attempts to achieve quality in the design, the execution of new buildings, and the rehabilitation and maintenance of existing ones. Therefore, a progressive demand from public administration is necessary and a growing interest should be generated in the agents involved in the process.

A change is needed that addresses ecological and social problems that are structural, not temporary, and transforms the organizational model of the sector [10], complemented by information, training, and advice so that companies understand the importance of this change and begin to introduce new socially responsible actions in their activities [11].

Ultimately, being socio-environmentally responsible becomes a management strategy that should be used throughout the entire life cycle of the construction of a building and a city [12].

Studies that have analyzed the above aspects to date mainly focus on the perception of the type of actions required, the dimensions that these actions cover in the projects, the implemented actions, and the impact of these actions [13]. However, the paradigm shift requires broadening the perspective and including the design phase of buildings, during which designers need to enhance their creativity and include more innovative ideas encompassing all the technology of the 21st century [3]. An example of this is smart buildings, which have an integrated and automated management of their facilities and services through home automation and can control the environmental variables of the building [14]. Sustainable construction and smart buildings are deeply interconnected, as both concepts share the common goal of improving energy efficiency, reducing their environmental impact, and optimizing resource use in the built environment, and they approach these objectives from complementary perspectives. Another example is zero-emission buildings, which have a zero CO₂ emissions balance during operation, or nearly zero-consumption buildings—NZEB buildings—when the balance between the value of CO₂ produced and the value consumed does not reach zero. In this change of the model, it would be interesting to also include other aspects that affect the quality of life of the building’s users, such as accessibility, hygrothermal comfort, indoor air quality, acoustic and visual comfort, protection from sunlight, green areas, and natural ventilation—which is so rare in public buildings and requires the use of forced ventilation or air conditioning systems—among other technical criteria. In addition, there is the link between the sustainable built environment and the conservation of biodiversity. Ref. [15] explores the adoption of sustainable construction practices that improve the preservation and promotion of biodiversity as an integral part of the built environment, because this improves the planet’s ability to adapt to climate change, air quality, flood mitigation, and the general health and well-being of people, issues that should be considered in policies that develop climate-resilient construction standards [16].

From the point of view of economic results, the incorporation of good socially responsible practices helps to perceive, carry out, and recover more sustainable practices that positively influence investment, issues that should be taken into account before making decisions [17]. These aspects have been integrated into international construction companies and into the public policies promoting them [18,19] and, little by little, they are being transferred to the rest of the smaller companies [20]. Ref. [21] analyze and compares the main policies aimed at promoting socially and environmentally responsible practices, including initiatives, reporting requirements and measures to assess the impact of Corporate Social Responsibility, especially focusing on answering the challenges posed in the Sustainable Development Goals (SDGs) developed by the United Nations [22], considering the need to homogenize certain measurement indicators in order to conduct general studies, although more specific indicators are used to complement the previous ones depending on the region [23,24].

The relationships between the circular economy, construction waste minimization, and SDGs have been analyzed by various authors [25,26,27]. The most notable insight is that socially responsible companies’ construction activities minimize waste and emissions, and the design and recycling of materials is integrated into construction methods, business models, tools used, and waste and energy measurement policies. For example, Ref. [28] performed a multidimensional analysis based on how to achieve net-zero carbon emissions in residential construction supply chains. These authors take into account important factors such as the life cycle of materials, incorporated energy, and the environmental impact of materials used in construction. They highlight the importance they attach to close collaboration and long-term planning between all parties involved in the residential construction supply chain to achieve a significant reduction in carbon emissions. All this without forgetting the technology and innovative solutions that can help achieve sustainable and environmentally friendly residential construction [29,30].

Therefore, the implementation of public policies aimed at sustainability in the construction sector is essential to mitigate its high environmental impact and promote a transition towards more environmentally responsible models. This sector is responsible for a significant portion of global energy consumption and waste generation, so its regulation through regulatory instruments, tax incentives, and technical standards is key to ensuring sustainable construction practices [31]. Public policies can promote energy efficiency, the use of recyclable materials, and the reduction in greenhouse gas emissions through legal frameworks that require compliance with environmental criteria from the design stage to the construction and maintenance of buildings [32]. In this sense, the role of the state is not only to establish regulations, but also to facilitate innovation and technical training, as well as to promote cooperation between public and private actors to achieve SDGs [33].

At present, work is being performed in the construction sector that, depending on the size of the company, is less manual and more industrial, in which fewer polluting materials, more advanced construction techniques, and greater sensitivity to bioclimatic design criteria are incorporated. These actions are aimed at achieving a more sustainable construction model that moves towards decarbonization [34,35,36,37]. The emergence of the use of new tools, such as Big Data and Building Information Modeling (BIM), is spreading in architecture, engineering, and construction, because it allows the creation of a digital model of the construction element, which favors decision-making and communication between stakeholders, as well as measuring their contribution to the sustainability of the sector [38,39].

In short, the construction sector is one of the most important sectors of the economy, but it consumes a lot of natural resources and energy, generating a large amount of waste and polluting emissions. In addition, the lack of attention to sustainability in the construction of buildings and infrastructure works has a negative impact on the health and well-being of the people who live in and/or use them [40,41], so it should be an issue that is taken into account and solutions need to be sought in public policies. But it is of utmost importance to know the opinion of the parties interested in formulating such policies [42] and reconsider governance in the sector and formulate new policies that reorganize, regulate, and evaluate the results [43], as well as respond to the challenges and demands of the construction and civil engineering sectors related to the following:

1.

The close links between large construction companies, property developers, investors, and local elites in urban growth coalitions, which have often enabled speculative investment in the built environment.

2.

Public work contracts, which are the most subject to corruption worldwide, impacting certain economic policy objectives, such as price stability.

3.

The environmental impact of the construction sector, which is observed throughout the life cycle of the final product (resources using water, energy, raw materials, etc.; the production of demolition waste or waste generated by the construction or design itself; waste from the use of housing or other construction works).

In summary, construction and civil engineering companies are the architects of the change in the city model, but urban policies are necessary as an instrument to promote the development of cities and seek responses to the demands of the new model of sustainable and integrated urban development, as well as indicators that allow the evaluation of the needs to create a smart and sustainable city [44,45,46,47]. When building sustainable cities, it is necessary to consider the following:

• The spatial and urban dimension of all the implemented policies,
• The impact that local infrastructures have on long-term sustainability,
• The forms of intra-urban and inter-urban mobility,
• The revitalization of life in its different areas,
• ……………. but we must go further.

3. Materials and Methods

3.1. Context

A study was conducted on the island of Tenerife (Canary Islands, Spain) in order to fulfill the main objective of this project and answer the research questions. Tenerife is an island where permanent (non-seasonal) tourism is the backbone of the socio-economic reality of Tenerife, with repercussions for the rest of the economic activities on the island.

The Spanish National Institute of Statistics (INE in Spanish) collects indicators that allow for the evolution of the achievement of certain SDGs that directly affect the topics dealt with in this study. Among these, SDG 7 (affordable and clean energy), SDG 9 (industry, innovation, and infrastructure) and SDG 11 (sustainable cities and communities) are worth mentioning, as they are strongly related to the subject of this study. However, the INE, for the moment, does not collect data disaggregated by island, and consequently the evolution of the achievement of these objectives is presented below with aggregated data for the Canary Islands.

A first approximation reveals the scarcity of data to perform an in-depth analysis with. The evolution of some of the data available indicates that, between 2011 and 2020, the consumption of electrical energy per unit of GDP stood on average at 18.2, a figure that is below the national average of 20.8, and the percentage of electrical energy generation from renewable sources with respect to the total from all sources has grown in recent years (6.8% in 2011, 17.5% in 2020). The rate of variation in CO₂ emissions in the Canary Islands between 2010 and 2019, compared to those emitted in 1990, is markedly high and, although it decreased between 2010 and 2014, going down from more than 65% to 33% in 2014, from then on it increased again, reaching a rate of 43.95% in 2019.

The objective focused on making cities and human settlements inclusive, safe, resilient, and sustainable is articulated in around seven goals. Specifically, the goal that refers to the population living in homes with certain housing deficiencies is one of those that needs to be taken into account in the Canary Islands. The data indicate that the average percentage of the population living in homes with deficiencies (leaks; damp walls, floors, ceilings, or foundations; or rot in floors, window, or door frames, among others) in the Canary Islands was 29.7% compared to the national average of 16.9% between 2008 and 2020. At this point, it should be noted that sparsely populated areas have the highest proportion of homes with housing deficiencies and that the percentage of people who suffer from noise problems coming from the neighborhood or from outside their home rose to 30.4% in 2020 (20.4% is the average for the 2010–2020 period).

Another noteworthy aspect is the one that includes efforts to protect and safeguard cultural and natural heritage, measured by the total per capita expenditure allocated to it by local governments. In the period 2015–2020, the average per capita expenditure in the Canary Islands was 15.4%, which is a relatively higher percentage than the national expenditure (13.8%).

With regard to reducing the negative per capita environmental impact of cities, at a national level, urban waste generated in 2021 amounted to 478.7 kg/per capita and the Canary Islands are well above the national average, generating the largest amount of waste per capita (548.9 kg/pc). The proportion of municipal waste dumped, in relation to the total generated and treated, has seen a notable decrease between 2014 and 2019, going down from 85.39% to 67.26%, respectively. In the case of recycled waste, the trend is reversed, more than doubling in the same period (from 14.61% in 2014 to 32.74% in 2019).

3.2. Methodology

The information that will serve as a basis for developing recommendations aimed at promoting the design and construction of sustainable cities was obtained through the following two channels.

3.2.1. A Qualitative Methodology of Documentary Research

Different documents and academic studies were analyzed, the conclusions of which suggest specific measures aimed at contributing to building sustainable cities. Among the documents used, those generated by the EU stand out, which outline the different strategies to be followed in the coming years, and other studies, such as the one in ref. [48], which presents key tools, methodologies, and recommendations for circular construction in regenerative cities, or the analyses by [49] that emphasize the importance of building sustainable cities based on the design of urban forests. Local administrations and the Island Council of Tenerife are conducting studies to assess the feasibility of developing urban forests. The development of urban forests in Tenerife would significantly contribute to climate change adaptation by mitigating the urban heat island effect and improving air quality in densely built-up areas. Furthermore, it would enhance water and soil management by reducing flood risks and controlling erosion, which is particularly relevant given the island’s complex topography. These green spaces would also promote local biodiversity, acting as ecological corridors for endemic species. From a social perspective, urban forests would improve public health and well-being by providing shaded areas, opportunities for recreation, and daily contact with nature. Lastly, they would generate positive economic impacts by increasing the value of urban environments, supporting more sustainable tourism models, and reducing public spending on health and urban infrastructure.

At the international level, public policies on sustainable construction focus on the development of regulations and standards such as the International Green Construction Code (IgCC), as well as certification systems such as LEED and BREEAM, which establish criteria to reduce the environmental impact of buildings. However, in the case of Spain, the criteria shaping the construction sector are primarily based on the guidelines set by the EU.

The EU has set out a comprehensive set of action lines for the creation and implementation of sustainable cities that are framed in international agreements such as the 2030 Agenda [22], the New Urban Agenda [47], and the United Nations Climate Change Conferences (COP28) [16]. These agreements establish broad objectives and goals for sustainable development, including the construction of inclusive, safe, resilient, and sustainable cities.

The EU has developed its own framework that translates into the so-called European Green Deal [50], whose main objective is to make the EU climate-neutral by 2050. Its objectives approach environmental challenges by transforming the construction sector and promoting sustainable practices in urban areas. This requires taking into account the different speeds and complexities between Member States, as well as laying a common basis for harmonizing a consistent framework for rapid, simple, and effective implementation of instruments and actions across the EU [51]. Thus, the EU bases its strategy on establishing an integrated approach to action, the development of responsibility through multilevel governance, evidence of actions and results, and the participation of stakeholders.

The main action lines for achieving sustainable cities are summarized below, grouped into four major areas of action to be used in the proposed actions. These actions are aligned with the international reference framework [52] and framed within the commitment of the European Green Deal, which affects the construction sector as the main driver of these.

1.

Legislative and Governance Scope

• European Climate Law [53]. This enshrines the goal of achieving climate neutrality by 2050, turning the climate objective into law as set out in the European Green Deal. It sets binding targets for reducing greenhouse gas emissions, including a reduction of at least 55% by 2030. The law also establishes a framework to ensure that all EU policies contribute to climate neutrality, including the integration of climate considerations in urban planning, investment in infrastructure, and regulation of key sectors. To this end, it defines a system for monitoring and evaluating progress, including recommendations to Member States to ensure compliance with the objectives.
• Urban dimension in European policies. The EU promotes sustainable urban development (SUD) with initiatives such as the European Union Urban Agenda [54], which is framed within the United Nations New Urban Agenda. This agenda seeks to strengthen the urban dimension in policies from the EU level to national and local governments, focusing on improving legislation, financing, and knowledge on urban issues.

2.

Energy Efficiency in Buildings [55,56,57]

• Renovation Wave Strategy [58,59]. This initiative of the European Green Deal seeks to improve the energy efficiency of buildings, reduce greenhouse gas emissions, and create jobs. It addresses three areas: energy poverty and the worst-performing buildings, the renovation of public buildings, and the decarbonization of heating and cooling. The strategy is complemented by the New European Bauhaus initiative, which promotes climate-friendly architecture.
• Energy Performance of Buildings Directive. This introduces ambitious standards to improve the energy efficiency of buildings, aligned with the Renovation Wave, for renovation and decarbonization. It contemplates various initiatives: it defines zero-emission buildings, establishes criteria for large renovations and standards for the mortgage portfolio, and it introduces renovation passports and facilitates the use of new performance metrics. It also sets time limits for new and existing buildings to achieve zero-emissions status (with exceptions for certain building types), defines Energy Performance Certificates and Minimum Energy Performance Standards, and sets rules for the installation of solar energy in buildings. It also addresses the phasing out of fossil fuel boilers by 2040, promotes bicycle and electric car infrastructure in buildings, creates the EU Building Stock Observatory to monitor the energy performance of buildings, and defines the legal framework for the Smart Readiness Indicator to assess the smart preparation of buildings [60].

3.

Renewable Energy [61]

• Renewable Energy Directive. This sets a target of 42.5% of renewable energy sources in the EU energy mix by 2030, and sets sector-specific targets (including 49% for buildings).
• REPowerEU Plan. This seeks to accelerate the transition to clean energy in response to the energy crisis following the Russian invasion of Ukraine. It includes measures to save energy, diversify supplies, and speed up permits for renewable energy projects.

4.

Circular Economy Action Plan (CEAP) [62]. This promotes sustainability throughout the life cycle of products. In the case of the construction sector, it is a strategy for a sustainable built environment that promotes circularity principles in buildings. It includes an updated proposal for the Construction Products Regulation to ensure reliable information on the performance of construction products [63].

The EU uses a variety of instruments to implement these action lines:

• Financing. This includes the so-called Investment Plan for a Sustainable Europe [64], through the EU budget itself (Multiannual Financial Framework 2021–2027 and European Structural and Investment Funds), the InvestEU Fund 2021–2030, the Mechanism for a Just Transition, and the Emissions Trading System (ETS) Funds, obtained from the auction of carbon emission rights of the ETS.
• Thematic partnerships for the identification of problems and the development of action plans within the framework of the implementation of the European Urban Agenda. This agenda also includes the European Urban Initiative for the period 2021–2027 at the budgetary level.
• Methodological support for the development of Sustainable and Integrated Urban Development Strategies.
• Research and innovation programs. Horizon 2020, BUILD UP, and BUILD UP Skills are complementary initiatives that allow the European Commission to support the building of renovation projects by creating a portal to share knowledge on how to make buildings more energy efficient, or by offering information on energy-efficient building renovations and zero-energy buildings [65].

3.2.2. A Direct Qualitative Participatory Methodology Through In-Depth Interviews with Key Stakeholders

The use of in-depth interviews with key stakeholders is a fundamental qualitative technique for understanding complex phenomena in their real-life context. This method enables the collection of rich and nuanced data by facilitating an open dialog that captures perspectives, motivations, and experiential knowledge of those directly involved in or affected by the topic under study [66]. In the field of sustainable construction, interviewing key stakeholders, such as policymakers, planners, architects, developers, and community leaders, allows for the identification of context-specific barriers, opportunities, and dynamics that might not be evident through quantitative methods alone. Furthermore, this technique encourages reflexivity and the co-construction of knowledge, contributing to a more grounded and contextualized interpretation of findings, which is particularly valuable in territorially and institutionally complex settings, such as island regions.

For this study, key informants were purposively selected based on their direct involvement in the development of sustainable projects on the island. Specifically, interviews were conducted with the heads of the most prominent construction companies in the region, identified for their track record in implementing sustainability criteria in recent projects. In addition, representatives from the two most influential local associations focused on sustainability and the promotion of responsible urban development were included. This purpose of sampling is aimed at ensuring expert, informed, and diverse representation from the sector.

Two differentiated semi-structured interview guides were used: one targeting construction and civil engineering companies (owners and architects), and another aimed at associations (community-based or sustainability-oriented). In both guides, the questions were organized into three thematic blocks: (1) diagnosis of the current situation, (2) needs and priorities for the coming years, and (3) limitations and challenges in implementing new actions aimed at the sustainable construction and development of cities (see Appendix A.1 and Appendix A.2).

All interviews were audio-recorded with the participants’ prior consent and subsequently transcribed verbatim for analysis. To ensure the validity and reliability of the findings, a thematic analysis approach was employed. This involved manual coding in multiple rounds, triangulating emerging categories across different participants, and cross-referencing the responses with the theoretical framework set out in Section 2 of the article. This procedure allowed for the identification of recurrent patterns and significant divergences in perspectives, thereby ensuring a robust and well-grounded interpretation of the collected data.

The participants who agreed to take part in the interview are those shown in

Table 1. Interviewees.

Interviewees	Activity
E.1.1	A company that designs and develops comprehensive projects for sustainability in construction
E.1.2	A company that designs and develops comprehensive projects for sustainability in construction
E.1.3	A company that designs and develops comprehensive projects for sustainability in construction
E.1.4	A company that designs and develops comprehensive projects for sustainability in construction
E.2.1	A residents’ association focused on changing the energy model towards renewable energy
E.2.2	An association for the defense of sustainability
E.2.3	An association for the defense of sustainability

Source: Prepared by the authors.

.

4. Proposal for a Portfolio of Action Policies

After the analysis of the documents and responses from key stakeholders, a general recommendation is proposed that sustainable urban planning should consider the strategic integration of urban forests as a comprehensive solution for Tenerife, for the following reasons:

• Provide ecosystem services essential to the quality of life of their inhabitants.
• Prevent heat islands, which are a natural cooling mechanism that contributes to mitigating impacts, especially in areas with high population density.
• Improve water management, since trees and vegetation, in general, in cities designed as urban forests absorb and filter rainwater, reducing the load on the city’s drainage systems and preventing runoff that can cause flooding and water quality problems.
• Control air and noise pollution, since vegetation and, especially, trees act as natural barriers to them.
• Improve public health, both physical and mental, since they offer spaces for leisure and physical activity, and relieve stress naturally.
• Promote biodiversity.

Below are a series of more specific recommendations that can serve as a basis for developing a strategic plan for the island of Tenerife. The proposed measures are grouped into a portfolio of action policies, following the typology shown in

Table 2. Portfolio of action policies.

Types		Measures
Macroeconomic demand policies, regulations, and reform policies	Fiscal/budgetary	Tax incentives, tax breaks, subsidies, etc. Investments in R&D&I.
	Simplification and restructuring	Reduction and/or remodeling of the different regulations affecting the sector and complementary activities.
Promotion and support policies	Motivation	Persuasion and incentives in the form of awards, certifications, etc.
	Culture	Assessment of the sector’s contribution to the transformation of cities into sustainable cities. Information for the population.
	Training and advice	Training in innovative products for entrepreneurs and workers in the sector. Advice from experts (university, business world, etc.)
Governance and collaboration policies	Planning, networks, and alliances	Governance. Public–private collaboration. Cooperation to share good practices.

Source: Prepared by the authors.

.

The following specific recommendations are grouped according to the type of action policy defined.

4.1. Recommendations Related to Macroeconomic Demand Policies, Regulatory, and Reform Policies

The policies below establish the appropriate legal and economic framework, in line with the objectives set out in European Climate Law.

• Rethinking existing regulatory policies, taking into account that the presence of lobbies does not bias government aid towards particular interests.
• Analyzing the objectives of incentive policies and towards whom or what they are directed because current measures favor undesirable situations, as is the case, for example, of biomass boilers (devices that provide only heating or heating and domestic hot water through the combustion of organic waste) instead of incentivizing the thermal envelope (set of surfaces of the building that separates the interior spaces from the exterior environment, a neighboring building, the land, or non-habitable spaces).
• Incentivizing environmental practices by applying tax breaks, which can be more effective than subsidies.
• Considering the socially responsible actions of companies in the sector as a requirement in public contracts.
• Demanding favorable architectural designs in the energy analysis of housing (bioclimatic and sustainable rehabilitation of buildings) considering the climatic uniqueness of each locality and the scenarios posed by climate change.
• Expanding and strengthening the electrical and hydroelectric networks, wind farms, and technologies that take advantage of sunlight.
• Establishing the optimal roofs for the placement of photovoltaic panels that allow greater energy production for the entire city.
• Implementing monitoring measures that allow rapid action to reduce losses in the supply networks that currently exist, appropriately managing their maintenance.
• Including certain requirements in the corresponding specifications of the projects (incorporating sustainability criteria in all stages of the building’s life cycle, taking into account the different microclimates of Tenerife, using materials that improve thermal and acoustic insulation, etc.).
• Designing buildings that reduce energy demand (considering solar orientation, natural ventilation, thermal insulation, and architectural design).
• Rehabilitating buildings and marginal neighborhoods with the same sustainability and accessibility criteria, using ecological and low carbon footprint materials.
• Regulating the rehabilitation of buildings to make them more inclusive and sustainable, considering the benefits of traditional Canary houses and respecting Canary architectural heritage.
• Investing in research and development to meet the objective of at least 32% renewable energy sources in final consumption by 2030.
• Promoting actions aimed at the creation of sustainable cities, providing funds for research, training, information, and the development or support of management tools and/or mechanisms.

• Regulatory integrity and efficiency

  Recommendation	Contribution to Sustainable Cities
  Rethink existing regulatory policies to ensure that the presence of lobbies does not bias government aid toward particular interests	Strengthens transparency and equity in policy implementation, ensuring aid promotes sustainable transformation
  Analyze the objectives of incentive policies to direct them correctly, for example, favoring the isolation of the thermal envelope instead of biomass boilers	Maximizes the energy efficiency of buildings and promotes passive solutions over potentially contaminating technologies

• Fiscal incentives and public procurement

  Recommendation	Contribution to Sustainable Cities
  Incentivize environmental practices through the application of tax breaks	Promotes the adoption of sustainable practices more effectively than subsidies
  Consider the socially responsible actions of companies in the sector as a requirement in public contracts	Encourages socio-environmentally responsible performance in the construction and civil engineering sectors

• Bioclimatic design and sustainable rehabilitation

  Recommendation	Contribution to Sustainable Cities
  Demand architectural designs that reduce energy demand (solar orientation, natural ventilation, thermal insulation, etc.)	Optimizes resource use and reduces energy consumption starting from the design phase
  Rehabilitate buildings and marginal neighborhoods using the same criteria of sustainability and accessibility, prioritizing ecological and low carbon footprint materials	Improves users’ quality of life and reduces environmental impact, promoting inclusion
  Regulate the rehabilitation of buildings to make them more inclusive and sustainable, respecting traditional Canary architectural heritage	Preserves cultural identity while integrating criteria for accessibility and efficiency
  Demand favorable architectural designs in the energy analysis of housing, considering the climatic uniqueness of each locality and climate change scenario	Ensures buildings are resilient and suited to local environmental conditions

• Investment in infrastructure and renewable energy

  Recommendation	Contribution to Sustainable Cities
  Invest in research and development (R&D) to meet the objective of reaching at least 32% renewable energy sources in final consumption by 2030	Drives innovation and ensures compliance with Renewable Energy Directives
  Expand and strengthen electrical and hydroelectric networks, wind farms, and technologies utilizing sunlight	Increases clean energy generation capacity and the island’s energy self-sufficiency
  Implement monitoring measures that allow rapid action to reduce losses in existing supply networks	Improves the efficiency and management of infrastructure
  Establish the optimal roofs for the placement of photovoltaic panels that allow greater energy production for the entire city	Maximizes the use of urban space for decentralized clean energy generation

4.2. Recommendations Related to Promotion and Support Policies

The policies below focus on motivation, culture, training, improving public information, and promoting responsible practices.

• Recognizing the efforts of the construction and civil engineering sectors in the adoption of cleaner and more efficient technologies that contribute to meeting certain standards through awards or certifications.
• Applying or teaching how to apply Environmental Product Declarations or Life Cycle Analysis as criteria for choosing construction materials and products.
• Using volcanic ash as a supplementary cementitious material because it provides a clear reduction in CO₂ emissions. Prioritizing traditional natural materials, such as local volcanic stone, wood, lime, and silicates, seeking to ensure compatibility with existing materials in cultural heritage preservation projects. Using specific materials, such as straw bales, compressed earth blocks (CEBs) and adobes, and even the restoration of caves as construction options.
• Conducting assessments of the needs and use of public and private spaces, taking into account accessibility for all (eliminate architectural barriers such as ramps, elevators, hallways, sidewalks, bathrooms, etc., and improve signage).
• Promoting the purchase of zero-kilometer products, supporting local producers on a permanent basis (not only at events).
• Establishing craft and local product markets with greater stability and frequency, in addition to those organized on public holidays.
• Creating or increasing green spaces, as well as community urban agriculture.
• Exchanging experiences and disseminating information about existing urban gardens.
• Creating or adapting spaces that allow socialization and the practice of sports and cultural activities in a responsible and sustainable manner.
• Improving information on cultural and traditional events and the frequency and coordination of public transport to attend them.
• Improving agricultural and irrigation infrastructure.
• Raising awareness and involving citizens in the need to save energy, using water responsibly, and adequate citizen management of waste.
• Training staff and professionals in the knowledge of the techniques and characteristics of sustainable construction materials.
• Encouraging consumers (public administrations, companies, and citizens) to buy and use certified products.
• Improving public information (both traditional and in format), content, and digital procedures contained on the websites of public administrations to make it more accessible to citizens.
• Organizing workshops, talks, and information sessions to educate citizens on the use of digital media and disseminating updated information.
• Disseminating good sustainable practices among companies, citizens and public administrations.
• Organizing information meetings, workshops, or courses to inform and advise on sustainable cultivation techniques and facilitating access to resources (municipal land for locating urban gardens, etc.).

• Materials, circularity, and heritage

  Recommendation	Contribution to Sustainable Cities
  Apply or teach how to apply Environmental Product Declarations (EPD) or Life Cycle Analysis (LCA) as criteria for choosing materials	Ensures informed decision-making about the real environmental impact of materials, aligning with the circular economy
  Use volcanic ash as a supplementary cementitious material for reducing CO2 emissions	Promotes decarbonization and the use of local resources, following the Circular Economy Action Plan (CEAP)
  Prioritize traditional natural materials (local volcanic stone, wood, lime, and silicates) and the use of options such as straw bales or cave restoration, ensuring compatibility with cultural heritage	Reduces the carbon footprint of construction, supports local production, and respects architectural heritage
  Promote the purchase of zero-kilometer products and organize craft and local product markets with greater stability and frequency	Boosts territorial circular economies, reduces external dependency, and decreases transport emissions

• Awareness, training, and information

  Recommendation	Contribution to Sustainable Cities
  Train staff and professionals in the knowledge of techniques and characteristics of sustainable construction materials	Ensures the viability and sustainability of proposed changes by equipping the sector with necessary skills
  Improve public information (traditional and digital) and the digital procedures of public administrations to make them more accessible to citizens	Fosters civic participation and reduces confusion in society regarding regulation
  Organize workshops, talks, and information sessions to educate citizens on responsible water use, energy saving, and waste management, as well as sustainable cultivation techniques	Promotes sustainable habits and civic engagement, a cross-cutting axis for sector transformation
  Recognize the efforts of the sector in adopting cleaner and more efficient technologies through awards or certifications	Motivates the private sector to invest in technologies and processes that meet environmental standards

• Community spaces and accessibility

  Recommendation	Contribution to Sustainable Cities
  Conduct assessments of the needs and use of public and private spaces, eliminating architectural barriers and improving signage	Guarantees inclusion and accessibility for all inhabitants, improving habitability
  Create or increase green spaces and community urban agriculture, and exchange experiences on urban gardens	Improves public health and air quality and supports local food production
  Create or adapt spaces that allow socialization and the practice of sports and cultural activities in a responsible manner	Revitalizes life in different urban areas and promotes well-being

4.3. Recommendations Related to Governance and Collaboration Policies

The policies below focus on planning, networks, alliances, and public–private collaboration.

• Promoting a strategic plan that prioritizes the development of renewable infrastructure and technologies to achieve greater energy self-sufficiency on the island.
• Strengthening coordination between public administrations and between these and companies in the sector and various associations, to carry out actions which are valued and requested by all interested parties.
• Continuing with the Tenerife + Sustainable Island Council program, which addresses the protection and management of natural areas, the prevention of forest fires, as well as the management of water, energy, and waste, due to its good results.
• Emphasizing specific management for tourist areas, which is appropriate and coordinated between the different public administrations (for the island of Tenerife, between the Island Council and town councils).
• Promoting investment and public–private collaboration in research projects or in collective socio-environmental processes in the Canary Islands through the Ecoejes. (Integrated strategy for sustainable urban development in land with a slope and where they try to establish 0 km economies in accordance with their resources. From the inland areas to the coast, it adapts to the reality of each area, studies their possibilities and proposes options to face current and future challenges.)
• Promoting the creation of energy communities that allow cities to advance towards a decentralized renewable energy management model (electricity, cooling, heating, desalination, transport).
• Using water from rainwater tanks and seeking solutions with sewage water, enabling the management of water treatment from the municipalities themselves.
• Improving connectivity between municipalities and the integration of transport according to the terrain.
• Reducing congestion on highways and waiting times, due to the lack of coordination between diverse types of transportation as well as excessive costs.

• Inter-administrative coordination and strategic planning

  Recommendation	Contribution to Sustainable Cities
  Strengthen coordination among public administrations, companies in the sector, and associations	Overcomes fragmentation of governance and ensures implemented actions are valued and requested by all stakeholders
  Promote a strategic plan that prioritizes the development of renewable infrastructure and technologies to achieve greater energy self-sufficiency on the island	Guides long-term transformation towards energy resilience, aligned with the REPowerEU plan
  Continue with the “Cabildo Tenerife + Sostenible” program due to its good results in the protection of natural areas and the management of water, energy, and waste	Leverages proven programs that holistically address resource management
  Promote investment and public–private collaboration in research projects, such as the Ecoejes strategy	Fosters urban development adapted to micro-territorial realities, seeking 0 km economies

• Water resource management and decentralized energy

  Recommendation	Contribution to Sustainable Cities
  Promote the creation of energy communities to advance toward a decentralized renewable energy management model (electricity, cooling, transport, etc.)	Increases the resilience of cities and decentralizes energy production
  Use water from rainwater tanks and seek solutions with sewage water, enabling water treatment management from the municipalities themselves	Optimizes water resource management, essential in an island context with limited resources
  Improve agricultural and irrigation infrastructure	Supports local food production and efficient water management

• Mobility and Connectivity

  Recommendation	Contribution to Sustainable Cities
  Improve connectivity between municipalities and the integration of transport according to the terrain	Promotes sustainable mobility and reduces the need for private vehicles
  Reduce congestion on highways and waiting times by improving coordination between different types of transport	Enhances the efficiency of the transport system and the citizens’ quality of life
  Improve information on cultural/traditional events and the frequency and coordination of public transport to attend them	Increases accessibility to services and cultural events using sustainable transport means

The recommendations below are aligned with the key action lines of the European Union (EU) for achieving sustainable cities, including the European Green Deal. For example, promoting bioclimatic building rehabilitation aligns with the EU’s Renovation Wave Strategy, while promoting energy self-sufficiency aligns with the REPowerEU Plan.

• Two issues are included in the legislative and governance scope. On the one hand, the European Climate Law of 2021 sets out the objective of climate neutrality by 2050 and a 55% reduction in emissions by 2030. This means that Tenerife needs to rethink existing regulatory policies, analyzing their objectives and who they are aimed at. This is the reason why the application of tax breaks to encourage environmental practices and the inclusion of social responsibility requirements in public contracts have been proposed. On the other hand, SUD can be achieved through initiatives such as the Urban Agenda. In the case of Tenerife, this means considering, above all, the spatial and urban dimension in all its policies, the impact of local infrastructures on long-term sustainability, the forms of mobility, and the revitalization of the different areas of the city. It is also important to promote coordination between public administrations, companies in the sector and associations to act jointly. It is recommended to continue with programs such as “Cabildo Tenerife + Sostenible” and to promote public–private investment in research and development projects, such as “Ecoejes”.
• Regarding energy efficiency in buildings, the “2020 Renovation Wave” Strategy stands out, which seeks to improve the energy efficiency of buildings. In Tenerife, this involves encouraging the bioclimatic and sustainable rehabilitation of buildings, considering the local climatic singularity and climate change scenarios. Optimal roofs should be established for the placement of photovoltaic panels and rehabilitating buildings and marginal neighborhoods with sustainability and accessibility criteria. The Directive on Energy Efficiency of Buildings should also be mentioned, which introduces regulations in this regard. In the case of Tenerife, the inclusion of requirements in the specifications of the projects is proposed to incorporate sustainability criteria in all stages of the building’s life cycle. Buildings need to be designed to reduce energy demand, considering solar orientation, natural ventilation, thermal insulation, and architectural design.
• Regarding renewable energy, it is worth noting the Renewable Energy Directive, which seeks to increase the share of renewable energy in the EU energy mix. In Tenerife, this implies the need to expand and strengthen electricity and hydroelectric networks, wind farms, and technologies that harness solar energy. It is also recommended to promote a strategic plan that prioritizes the development of renewable infrastructure and technologies to achieve greater energy self-sufficiency, following the REPowerEU Plan.
• Regarding the circular economy, the Circular Economy Action Plan (CEAP) seeks to promote circularity in the economy, including the construction sector. In Tenerife, the importance of using volcanic ash as a supplementary cementitious material to reduce CO₂ emissions is highlighted, as well as prioritizing traditional natural materials and encouraging the purchase of local products.

5. Discussion

Sustainable construction, as established in the theoretical framework, is not limited to the conscious choice of materials and processes. Instead, it encompasses the comprehensive planning of the building’s life cycle and its integration into the urban environment, broadening its scope to include ecological, economic, and social factors. This perspective is complemented by the findings presented, which offer a series of practical recommendations aimed at guiding the transformation of the sector, especially in island contexts such as Tenerife.

From a theoretical perspective, the transition to a sustainable urban model requires a profound rethinking of the construction production system. As Ref. [10] emphasizes, ecological and social problems are structural in nature, and their resolution requires organizational changes within the sector, supported by public policies and corporate commitment. These ideas are reflected in regulatory recommendations, which include, for example, prioritizing bioclimatic design and adjusting incentive policies to avoid counterproductive outcomes, such as the promotion of polluting technologies (e.g., biomass boilers) instead of passive solutions such as improving the thermal envelope.

One of the most notable contributions of the theoretical framework is its emphasis on socio-environmental responsibility as a management strategy. This is clearly reflected in the findings which propose including sustainability criteria in public contracts and offering tax benefits to responsible practices. This alignment between theory and practice demonstrates a comprehensive understanding of the role that public and private actors must play in transforming the urban model. Ref. [12] emphasize that responsibility must permeate all stages of the building’s life cycle and urban planning, a vision reflected in proposals related to strengthening energy networks, promoting sustainable renovation, and encouraging the use of local materials.

Likewise, the theoretical framework highlights the importance of early architectural design that incorporates innovation, technology, and environmental comfort. This idea is reflected in proposals such as the rehabilitation of marginalized neighborhoods under accessibility and sustainability criteria, or the design of buildings aimed at minimizing energy demand through natural ventilation, solar orientation, and low-carbon materials. In this case, the application of what [3,14] identifies as pillars of smart and zero-emission buildings. Refs. [29,30] complement this approach by emphasizing the role of technological innovation and digital solutions, particularly in the context of sustainable residential housing.

Furthermore, the economic dimension of sustainability is strongly supported both in the theoretical framework and in practical recommendations. Promoting the purchase of local products, the use of indigenous materials (volcanic ash, stone, wood), and the promotion of artisanal markets not only seeks to reduce emissions and waste but also to foster territorial circular economies aligned with the CEAP and the SDGs. Ref. [17] highlights how these practices also contribute to more informed investment decisions and improving public perception of the sector.

In terms of governance and public policy, the theoretical framework emphasizes the need to listen to key stakeholders and reformulate policies based on data, indicators, and initiatives such as the Urban Agenda. This is reflected in the recommendation to continue with programs such as Tenerife + Sostenible and promote the Ecoejes strategy, which seeks urban development adapted to micro-territorial realities. The creation of energy communities and the improvement of water infrastructure also represent structural and decentralized responses, aligned with the resilient and participatory city model. Ref. [40] highlights that reorganizing and evaluating the sector through a new governance logic is key to achieving a true paradigm shift.

From a circular perspective, the findings of [28] on net-zero supply chains are reflected in the proposal to foster long-term collaborations and utilize tools such as Life Cycle Assessments and Environmental Product Declarations. These recommendations are especially relevant in fragile territories such as islands, where resources are limited and efficiency needs to be maximized. Refs. [25,27] also argue that integrating the circular economy into construction requires transforming not only methods but also business models and policies, an idea echoed in many of the proposed measures.

Although the theoretical framework strongly emphasizes the relationship between sustainability and biodiversity [15], this connection is somewhat diluted in the practical recommendations. While the promotion of green spaces and urban agriculture is addressed, this link could be further reinforced through specific proposals for urban ecological protection and restoration, in line with the approaches outlined by [16] on climate resilience.

Likewise, both the framework and the findings underline the need for training and education as a cross-cutting axis for the transformation of the sector. Public awareness, professional training, and access to both digital and in-person information are key to ensuring the feasibility and long-term sustainability of the proposed changes. In this regard, Ref. [11] argues that the introduction of socially responsible actions in business activities cannot occur without the support of training policies, advisory services, and technical assistance.

Finally, the relationship between speculative urbanism and vested interests—one of the key challenges raised by the theoretical framework—is addressed in the findings through the recommendation to depoliticize government aid and prevent its capture by lobbying groups. This approach reflects a clear intent to strengthen transparency and equity in the design and implementation of public policies, which is essential for consolidating the legitimacy of the transition towards more sustainable construction. As [44] warns, without a profound reconfiguration of urban policy, it will be difficult to achieve a truly sustainable and inclusive city.

6. Conclusions

The main objective of the present work has been to propose a series of recommendations to public administrations for the development of economic policies that encourage the contribution of the construction and civil engineering sectors to the design and implementation of sustainable cities. The study has responded to this objective and to the research questions and focused on gathering information from companies and associations on the state of the art, the type of actions necessary to fulfill this objective in the coming years, and the limitations that may be encountered in implementing them.

The articulation between the theoretical framework and the findings demonstrates a coherent and multidimensional approach to sustainability in the construction sector, which is particularly relevant for insular regions such as Tenerife. The recommendations presented are not only aligned with European guidelines but also address ecological, social, and economic challenges through concrete, scalable, and context-specific measures. However, the success of these proposals will depend on the degree of institutional, corporate, and civic commitment, as well as the capacity for inter-administrative coordination and continuous evaluation of implemented policies.

The need to develop a general action plan that outlines the action lines for the transformation of cities is made clear, deciding whose priority is the optimization of resources, the minimization of energy and water consumption, the recycling of waste, the generalized reformations of buildings and leisure areas, and communications. A plan that goes beyond the scope of housing and has a vision at the urban level in its entirety to, on the one hand, change the paradigm towards structural ecological and social solutions, implementing a new model of habitability focused on the needs of people and the improvement of the environment and its services, and, on the other hand, to simplify the different regulations to reduce the confusion detected in companies, public administrations, and society in general, in this regard.

The portfolio of action policies should include an evaluation of the existing regulations and new updated proposals, the adoption of more homogeneous socially responsible criteria to be considered in public contracts, tax incentives, targeted subsidies, etc.

In short, knowing the problems and possible solutions that companies and associations demand is essential, on the one hand, to judge whether the economic policies carried out to date are acceptable and can be implemented, and, on the other hand, because they help policymakers in making decisions on new action lines. Governance, public–private collaboration, institutional efficiency, and the socially and environmentally responsible performance of companies in the sector are key factors.

Finally, it should be mentioned that, in the initial project, the possibility of interviewing key representatives of the public administration with responsibility in this area was raised, but it was difficult to fit in-depth interviews into their schedules, or they said that they did not have time for an interview of this nature. Therefore, it is hoped to continue with a future line of work that collects the opinions of public representatives.