Urban vulnerability can be defined as the process produced by the combination of many disadvantaged dimensions in which any possibility of upward social mobility, and overcoming social condition exclusions, is extremely hard to achieve. Usually, the more vulnerable and distressed areas lack basic services and have a higher number of obsolete buildings, unfavorable social characteristics, vulnerable people, and more prominent gender differences.
According to the World Organization Prospects of 2018, Europe had nearly three-quarters of its population living in urban areas in 2018, and this is expected to reach 80% in 2040 and nearly 85% in 2050. The United Nations (UN) 2030 Agenda for Sustainable Development and its 17 Sustainable Development Goals (SDGs) adopted by UN Member States in 2015, embody a roadmap for progress that is sustainable and leaves no one behind. The 11th SDG focuses on sustainable communities and cities and calls for action to make cities and human settlements inclusive, safe, resilient, and sustainable. The 11th SDG also states that taking into account gender views is crucial to developing sustainable urban environments to minimize inequality. The 5th SDG, specifically centers on gender equality and calls for urgent action to eliminate the many root causes of discrimination that still limit women’s rights in private and public spheres. These two goals are not the only ones that include gender equality as an integral part of inclusive and sustainable development. Achieving gender equality is transversally included in all 17 SDGs. The UN recognizes that only by ensuring gender equality, will there be justice and inclusion, economies that work for all and leave no one behind, and a sustained and shared environment for present and future generations 
The New Urban Agenda (NUA) 
is aligned with the SDGs and states that urbanization is a driving force for sustained and inclusive economic growth, social, and cultural development and protection of the environment. Consequently, special attention should be paid in urban areas to people in vulnerable situations (women, children, people with disabilities, and the elderly) by developing programs for regenerating distressed and inadequate areas such as slums. It is clear that urbanism in the 21st century needs to adapt to sustainable development, searching for inclusive and person-centered models, greener and more physically active areas, and spaces that are resilient to climate change through the reconfiguration of urban and transport structures 
. Moreover, urban areas need to look for more social-oriented models promoting inclusion of vulnerable people and a commitment for gender equality, aligned with gender views.
Gender views are necessary for urban planning, as stated by the SDGs and NUA. However, the inclusion of gender views in urban planning policies (gender mainstreaming in urbanism, GMU) is limited 
. Recently, it was found that, even in the Global North, the 5th and 11th SDGs have not been appropriately included in the urban planning of cities and towns. Specifically, government and private institutions (at all levels and processes) have not considered gender views from the urban population as well as gender experts. This needs to advance so that changes can last through time and can reach inclusive neighborhoods 
. A strategy towards including GMU involves the integration of a gender perspective in the preparation and content of policies and an appropriate representation of gender across the decision-making process 
. In addition to gender, other factors, such as age, mobility levels, socio-economic backgrounds, and social roles, must be taken into account 
. Physical and social interaction must also be analyzed, for instance, how different social groups acquire public spaces and how they utilize them. Therefore, a more inclusive urban planning model could contribute to reduce inequalities by planning safer public spaces and adequate mobility chains, more facilities to support reproduction and care work, spatial structures that encourage new forms of collective self-organization, and safe and convenient transportation means among other factors 
. This is especially relevant in areas where a higher index of vulnerable populations are concentrated. Usually, the more
vulnerable and distressed areas lack basic services and have a higher number of obsolete buildings, unfavorable social characteristics, vulnerable people, and more prominent gender differences
. Since economic resources are limited, vulnerable areas should be prioritized to undertake urban interventions, as they have more problems and more urgent needs. In the 1960s, Henri Lefebvre highlighted that many urban processes had been a contributing source of inequality and injustice. This was due to the consideration of the space, such as a simple container of buildings and population, while he argued that space was constituted by social relations and that all groups should have a “right to the city”. Since then, other authors have focused on this aspect, as it was analyzed by Susan Fainstein in 
. Fainstein pointed out the role of urban policies to benefit disadvantaged social groups by implementing programs to enhance equity and to promote diversity, ending discriminatory zoning. GMU reflects all these issues perfectly and, as a result, a more inclusive model can be achieved by adopting this view 
. The inclusion of GMU and gender mainstreaming in policy making is a transformative approach that has great potential for social development and change 
. However, current literature in urban planning is scattered and lacks a standard method that may help decision makers evaluate vulnerability with a gender equality perspective, while, at the same time, looking at accommodating diversity, variation in geomorphological features, historical evolution, and particularities of urban environments.
2. Inclusion of Gender Views for the Evaluation and Mitigation of Urban Vulnerability: A Case Study in Castellón
Early studies in gender inclusion date back to the 1960s and contribute to visualizing the lack of attention paid so far to women’s needs and requirements at the urban scale. In 1962, during a conference on urban planning in Berlin, Elena Arregui Cruz-López collected evidence related to housing and urban planning from the perspective of women in the report entitled “Participation of Women in Housing Problems” edited in 1964 by the Ministry of Housing 
. Hayden (1980) identified the need to consider women’s activities and how these fit into the environments of home, neighborhood, and city 
. With this new perspective, in the 1980s and onwards, theoretical interest towards gender equality increased as scholars recognized that progress was slow and sector based. This work resulted in a relevant step to advance gender equality by increasing the social visibility of groups that had been particularly neglected during the planning process 
. The concept of gender mainstreaming was first introduced at the 1985 Nairobi World Conference on Women (UN, 1985). It was established as a strategy in international gender equality policy through the Beijing Platform for Action, adopted at the 1995 Fourth United Nations World Conference on Women in Beijing, as a tool to promote gender equality at all levels (UN, 1995). In 1997, the United Nations Economic and Social Council (ECOSOC) defined gender mainstreaming as: “The process of assessing the implications for women and men of any planned action, including legislation, policies or programmes, in all areas and at all levels. The ultimate goal is to achieve gender equality”. In 1998, the Council of Europe defined gender mainstreaming as “The (re)organisation, improvement, development, and evaluation of policy processes, so that a gender equality perspective is incorporated in all processes by the actors normally involved in policy-making”.
Following the efforts from the Council of Europe, the EU adopted the concept of gender mainstreaming in the Treaty of Amsterdam (1999) as a policy that placed the contribution of both men and women at the center of attention for development 
. According to Valdivia, the first GMU studies 
were crucial for increasing the theoretical interest in the connections between planning and gender and establishing the link between gender roles and spatial divisions. Greed emphasized the role of street layout, building density, alongside the design of houses in social issues such as crime, security, childcare, traffic problems, and accessibility 
. Larsson identified the imbalance between public–private, reproduction–production, and paid work–unpaid work in relation to the various levels of planning 
. Carrasco analyzed the design of public space from the perspective of car users, resulting in a progressive loss of urban space for pedestrians and unsafe, congested, and noisy streets 
. Sánchez de Madariaga argued that the care crisis entails a great opportunity to make a structural critique of the socioeconomic system and to incorporate gender as a central category of economic discourse 
. Gender mainstreaming has now been widely recognized as a strategy that improves neighborhood and housing industry planning, creates suitable urban patterns, reliable transportation systems, and better structures of social services by increasing the participation of users, both men and women, in the planning and design of urban environments.
The Vienna City Council was a pioneer in gender mainstreaming applied to urban planning. In the 1990s, the Vienna Municipality introduced the gender perspective in public spaces and social housing and developed a set of actions resulting in many beneficial results 
. By considering all users of public spaces, not only from a gender perspective but also from a social-, ethnic-, and health-related perspective, the city was able to better meet the needs and demands of all its citizens and thereby improve the quality of public services. Benefits included greater accessibility to cemeteries for the elderly, better lighting for increased safety in public spaces, and gender-sensitive education in day care centers to avoid traditional gender roles, among others. The Manual for Gender Mainstreaming in Urban Planning and Urban Development, published by Vienna’s City Council in 2013, is a testament to this. It states that gender mainstreaming should be viewed as a “vertical issue” that supports the overall consideration of gender-sensitive aspects in all steps of the planning process to ensure high-quality planning 
. Another successful implementation of gender mainstreaming into urban planning was the Women in Cities International work, initiated in Montreal in the early 1990s and widely adopted in gender-sensitive space design across Canada 
. It aimed to increase the capacity of being seen in the public space by encouraging women’s route choices within urban environments and an increase in activity in the streets 
. Other successful examples of gender mainstreaming applied to urbanism include the cities of Dortmund in Germany 
, Thiva in Greece 
, Caracas in Venezuela 
, Bristol in the UK 
, and Blantyre in Malawi 
. The inclusion of gender equality is an opportunity to find theoretical and political convergences between feminist economists and other schools of critical economists. Major structural changes in societies, such as the need for support services for families and dependent people, the recognition of care work for people, transportation and accessibility, and safer spaces, pose new challenges to urban planning, and GMU can practically guide these changes.
The case study of Castellón shows the update of a prior model of definition of vulnerable areas. The new model, called AIM (Advanced and Inclusive Model) is a more comprehensive model with an integrated approach that includes the gender perspective. The AIM focuses on vulnerable neighborhoods in the city, where groups of disadvantaged people usually live, contributing to the social equality of citizens. The results of the case study showed the importance of accessibility and roads to minimize vulnerability. Likewise, the results showed that new developments and rehabilitation projects increase the well-being of people and must be implemented, especially in areas with low housing development. The case study also showed that interventions need to be prioritized, as the budget can determine the success of regeneration projects, many of which are abandoned due to the lack of sufficient funds or by tackling non-pressing needs. The results demonstrate that prioritizing areas with specific needs, such as social programs and women’s programs, may lead to a significant decrease in vulnerability. Women have typically relied on the family structure for economic development and on less stable jobs; thus, including indicators that measure these aspects and point out areas where jobs for women can be increased may help mitigate vulnerability. One key consideration for any city intending to apply the AIM is to look at available information, specificities of the city, population, and vulnerable areas so that indicators can better reflect actual conditions. The inclusion of gender views is a transformative approach and has a great potential for social change, focusing on the circumstances that aggravate the situation of vulnerability.
3. Key Topics for Gender-Sensitive Urban Design
From the desk review of the literature, 20 key topics for the applicability of gender views in urban planning were identified:
1. Compactness: A compact city makes it considerably easier to reconcile the requirements of work and family life 
2. Public open space: parks and reserves; sport fields; riparian zones, such as streams and riverbanks; greenways and trails.
. These spaces are available for users and where the public life of the city plays out and civic identity is defined 
3. Mobility and public transport is often framed as a vital component to developing sustainable cities 
. A well-designed and citizen-friendly transportation system improves the compatibility of work life and daily tasks 
4. The perception of safety in public spaces promotes the feeling of security in public spaces, and special attention must be paid to provide adequate lighting in walking paths for pedestrians and walls, fences, and stairs that create hidden corners with
difficult accessibility. According to Chestnutt, linking buildings to outdoor spaces can create amenity value and ensure sufficient options for the appropriation of public spaces 
5. Walkability and accessibility: This refers to wide sidewalks, with differentiation of materials, colors, and textures, railings and ramps in sloped areas, differentiated pedestrian crossings with traffic lights, and benches with shadows. This not only supports people with reduced mobility but also facilitates people’s lives with caregiving and family responsibilities
6. Mixed-use planning in terms of urban development where residential, commercial, cultural, institutional, or entertainment uses are physically and functionally integrated and provide pedestrian connections
7. Care facilities and equipment supply is expanded when society recognizes, assumes, and values work derived from gender roles. The goal is to create or improve access to care facilities for dependent people, the elderly, or children, ensuring accessible and affordable services. It enables people with care responsibilities to balance these with their work activities;
8. Visibility of women: Gendered stereotypes can have the effect of promoting fixed ideas about what women can become and their needs
9. Housing design to improve affordability: Currently, there are different types of families, so various funding and development models as well as different types of housing all guarantee a high level of potential for assimilation of the diversity of user groups;
10. Energy-efficient housing: The deterioration and lack of insulation in many homes results in higher costs to keep them at a suitable temperature, which is not affordable. The urban agenda of the EU partnership on housing has found that women and,
especially low-income and vulnerable groups of women, are more likely to experience energy poverty
11. Accessible housing should be seen as a way to facilitate greater autonomy for dependent people, guaranteeing universal accessibility to and inside houses
12. Quality housing: Marginalized women are also likely to be impacted by the lack of quality housing. This results in temporary or precarious accommodation
13. Disaggregated statistical data by gender are of interest to sociologists and social workers to determine actual statistical results 
14. Violence and security: Violence against women is a violation of human rights. Municipal plans could be revised to include steps to limit violence against women by providing shelter and refuge and support for organizations offering special assistance to women . Security, related to the influence of police interventions on human safety and other factors contributing to the well-being of neighborhoods, should be incremented 
15. Social housing involves ensuring allocation and other resources based on balanced social priorities. Women with low incomes are disproportionately represented, as they are often the head of households in single-parent families. Thus, poor women and single parents are more reliant on social housing than men
16. Paid and unpaid work: Urban planning strategies are often based on a unilateral vision of the economy; that is, it only measures the paid work of employed people who drive a car to get to work and during regular working hours. Plans should include aid for unpaid work 
17. Social subsidies: Economic aid is available for basic needs , housing expenses and job training. Data regarding beneficiaries of social service aid inclusion indicate there is a vulnerable population of women who take care of dependent people and do not have access to these aid programs ;
18. Level of education: Urbanization involves major changes in the way people work and live. It offers opportunities for improved standards of living, higher life expectancy, and higher literacy levels
19. Housing market: The cost of accommodation in inadequate and overcrowded housing takes up a disproportionate part of low-income people’s earnings 
20. Women’s and men’s participation in formal and informal decision making is uneven. Gender equality must be guaranteed at all levels (OCDE, 2020).The results of the case study show the importance of accessibility and roads to minimizing vulnerability. Likewise, the results show that new developments and rehabilitation projects increase the well-being of people and have to be implemented, especially in areas with low housing development. The case study also shows that interventions need to be prioritized as the budget can determine the success of regeneration projects, many of which are abandoned due to insufficient funds or by tackling non-pressing needs. The results demonstrate that prioritizing areas with specific needs such as social programs and women’s programs may lead to a significant decrease in vulnerability. Women have typically relied on the family structure for economic development and on less stable jobs, so including indicators that measure these aspects and point out areas where jobs for women can be increased may help mitigate vulnerability.
The inclusion of gender views is a transformative approach and has a great potential for social change, focusing on the circumstances that aggravate the situation of vulnerability. By linking social vulnerability to policy making, strategies to reach inclusive and sustainable neighborhoods via a gender equality approach can be developed.