Evaluating Accessibility Solutions in Collective Residential Buildings: Field Research in Southeast Spain

Abstract

With the ageing of the population in Western countries, the prevalence of disability and mobility problems is increasing, highlighting the urgent need to improve accessibility in environments where people spend a significant amount of time, such as collective housing. This paper examines the accessibility of building entrances in collective housing in the Region of Murcia, south-eastern Spain, where 9.8% of the population is estimated to live with disabilities. Starting with a thorough review of national and regional accessibility regulations, this study applies a robust methodology by conducting fieldwork in 150 buildings to assess compliance and identify barriers. The methodology involved a systematic assessment of the accessibility of entrances, using criteria derived from the regulations, and a specific proposal of the accessibility solutions required for each case. The key findings show that the most effective way for improving the accessibility is a properly constructed ramp, with over 40% of buildings requiring the installation or improvement of ramps, either as a stand-alone solution or in combination with other adaptations. In 54% of cases, a multi-faceted approach was required to meet accessibility standards. It was also noted that older buildings typically require higher adaptation costs. Based on these findings, the study provides specific recommendations, such as the construction of ramps and other critical interventions, to improve the accessibility of buildings. These recommendations have the potential to guide public policy and drive improvements in urban planning to make residential areas more accessible.

1. Introduction

Common access areas in residential buildings play a vital role in the daily lives of their residents, requiring ongoing improvements to ensure accessibility for all. The importance of such enhancements is further amplified by the demographic shift towards an aging global population, particularly in Western societies, as highlighted by the World Health Organization [1]. These spaces, which serve as the transition from private dwellings to public spaces, must be designed to accommodate individuals of all abilities. The concept of a universal design emphasizes the creation of environments that are usable by everyone, to the greatest extent possible [2]. For example, Steinfeld and Maisel emphasized the importance of creating spaces that are not only legally compliant with accessibility standards, but also designed to accommodate a wide range of users [3].

The present research seeks to develop recommendations for the adaptation of existing residential buildings to better serve individuals with motor disabilities, advocating for the widespread implementation of universal design principles [4]. The focus on universal accessibility underscores the broader societal benefits that stem from making environments more accessible. In essence, our goal extends beyond achieving universal accessibility; we strive for progress in the integration of people with disabilities, which aligns with the philosophy that an accessible environment benefits not only those with disabilities, but the entire population [3,4]. Wherever a person with a disability can navigate, so can everyone else, although the reverse is not always true.

The importance of creating inclusive and accessible environments is well-documented in the recent scientific literature. For example, Hamraie [5] provided a critical analysis of the concept of a “universal design” and its application in creating spaces that accommodate a diverse range of bodies and abilities. Additionally, the role of technology in promoting accessibility within smart homes was explored by Margot-Cattin et al. [6], who identified that smart home technologies can support aging in places, but require careful consideration of user diversity. The benefits of technology to enhance accessibility for people with disabilities have been extensively studied, for example, applied to access to shops and commercial premises [7], and to the access and use of beaches [8].

Furthermore, Steinfield and Maisel [3] offered practical guidance on implementing universal design in architecture, providing case studies and design strategies that prioritize inclusivity. Some studies also incorporate fieldwork; for example, Imrie’s research [9] evaluates the effectiveness of building regulations in fostering high-quality and accessible housing, with field assessments conducted in new housing developments. Sanford [10] discussed universal design in the context of rehabilitation, with case studies and fieldwork that demonstrate how design can be used to accommodate people with disabilities. Heylighen et al. [11] presented an inclusive design approach to the built environment, with fieldwork involving users with various abilities to identify the challenges and opportunities of inclusive design. These contributions highlight a trend towards recognizing and addressing the varied needs of individuals in the design of their living and urban environments, underscoring the importance of inclusivity in the field of design.

However, to date, most research has focused on the accessibility of public buildings. For example, Evcil [12] studied the accessibility of public buildings in Istanbul for people in wheelchairs, finding that 79% of the entrances to the buildings complied with the legal requirements. Jamaludin and Kadir [13] focused on the accessibility to three popular tourist attractions in Malaysia, performing observations and interviews with the users. They found that the oldest facilities were the least accessible. University facilities have also been the target of study in different works, such as [14,15].

Some interesting state-of-the-art reviews can also be found, focusing on accessibility in public buildings. For example, Welage and Liu [16] carried out a review of studies in the wheelchair accessibility of public buildings, selecting 12 relevant studies. They concluded that not one of these studies reported 100% accessibility. More recently, Carlsson et al. [17] performed a scoping review of public building accessibility. They selected 40 publications, of which 30 were technical reports and 10 were based on user interviews. On the other hand, the main accessibility adaptations have also been studied, such as the manual from the United Nations for barrier-free environment designs [18], which includes elements such as ramps, elevators, lifts, stairs, and handrails, and the guidelines for the accessibility of the USA government by the Americans with Disabilities Act [19]. However, these documents are more focused on accessible design and not in the adaptation of existing buildings. In some cases, the adaptation of existing buildings is studied by means of checklists, such as the work by Badawy et al. [20], which proposed a complete checklist of 56 items based on the recommendations of [21]; nevertheless, they are more a list to assess accessibility than a proposal of solutions for each case.

In conclusion, it can be seen that there are two main research gaps that this article attempts to fill. First, the lack of extensive studies dealing with the accessibility of private spaces. Second, the necessary relationship between the study of the situation of existing buildings and the proposal of accessibility solutions. As we have seen, most of the current studies focus on public spaces, and we have not found any that, like our case, relate the current situation with the accessibility adaptations required for each case.

The ultimate purpose of the present research is to provide a current, comprehensive, and detailed overview of the accessibility solutions needed in residential buildings, with particular reference to the specific case of the Region of Murcia. Our methodology includes a thorough review of accessibility regulations, both at national and regional levels, as well as an extensive and detailed fieldwork aimed at assessing the current state of building entrances. This fieldwork provides a basis for recommending practical enhancements that prioritize the autonomy of disabled individuals [21]. Particularly, the improvements that are considered most appropriate for each building studied are proposed. In this way, the most recurring solutions can be studied and compared with the criteria established by the regulations, looking for the autonomy of the person with disabilities to predominate, compared to other criteria such as economic ones.

In line with the principles of equal opportunities, as outlined in the Convention on the Rights of Persons with Disabilities (CRPD) [22], this work promotes the elimination of barriers and the adoption of positive measures to achieve an accessible and inclusive built environment. By doing so, we aim to contribute to the creation of spaces where individuals with disabilities can enjoy the same opportunities for participation as those without disabilities. The significance of improved accessibility extends beyond the disabled community, benefiting a diverse population including the elderly, families with baby stroller, people carrying shopping trolleys or luggage, and anyone who may temporarily experience reduced mobility.

The rest of the paper is organized as follows. In Section 2 describes the materials and methods, which include the study of the legal regulations in accessibility, the proposal of the accessibility solutions, the consideration about the cost of the solutions, and the design of the fieldwork. Then, Section 3 presents the results of the fieldwork and Section 4 discusses the main findings. Finally, Section 5 draws the conclusions of the study.

2. Materials and Methods

The present study has been divided into four primary phases. Initially, we conducted an analysis of the prevailing accessibility regulations at various governmental tiers, encompassing national, regional, and local levels. These regulations are contained in the Basic Safety Document for Use and Accessibility (DB-SUA) of the Technical Building Code [23], supplemented by its Support Document DA DB-SUA/2 [24]. The latter outlines permissible variances or tolerances for pre-existing buildings—specifically, those whose permit applications were submitted before September 2010—where it is impracticable to comply fully with the stipulations of the DB-SUA. Subsequently, the second phase focused on examining how individuals with disabilities interact with different kinds of obstacles within the common areas of residential buildings to assess the accessibility features. The third phase entailed comprehensive fieldwork to evaluate the present state of building accessibility within the Region of Murcia. The final phase involved examining the proposed accessibility interventions for each identified scenario, culminating in the synthesis of the study’s key insights and conclusions.

2.1. Accessibility Regulations

The current accessibility regulations in the Region of Murcia are stipulated by the Royal Decree (R.D.) 450/14 June 2022 [23], which amends the Technical Building Code initially established by R.D. 314/17 March 2006, at the national level [25]. At the regional level, they are further defined by Law 4/27 June 2017, on Universal Accessibility in the Region of Murcia [26], which is awaiting further regulatory development. Under the first transitional provision of the aforementioned law, the regulations set forth in Law 5/7 April 1995 on the habitability conditions in residential buildings and the promotion of general accessibility in the Autonomous Community of the Region of Murcia [27], Decree 39/4 June 1987, which addresses the removal of architectural barriers [28], and the Order of 15 October 1991, from the Ministry of Territorial Policy, Public Works, and the Environment concerning accessibility in public spaces and buildings [29] remain in effect. These existing regional regulations will continue to apply provided they do not conflict with the new provisions introduced by Law 4/2017.

To complement R.D. 450/2022, the Support Document titled DA DB-SUA/2 [24] addresses the effective adaptation of accessibility conditions in existing buildings, a topic that this article aims to explore in depth. The latest version of this document was published in June 2018, and it is this version that is referenced throughout this article.

These regulations propose explorations in line with this research, delving into the current standards governing built environments by adopting the principles of “universal accessibility” and “design for all”. Universal accessibility is defined as the set of characteristics that environments, processes, goods, products, services, tools, and devices must possess to ensure they are comprehensible, usable, and practicable by all individuals in conditions of safety, comfort, and the most autonomous and natural manner possible [30]. This concept is predicated on the “universal design” or “design for all” approach, which does not preclude making reasonable adjustments when necessary, as outlined in Article 2(k) of R.D. 1/29 November 2013, which ratifies the Consolidated Text of the General Law on the rights of people with disabilities and their social inclusion [30].

Conversely, “universal design” or “design for all” is conceptualized in Article 2(l) of the same R.D. as the activity through which environments, processes, goods, products, services, and tools are created to be accessible to the widest possible audience without the requirement for adaptation or specialized design. This notion of universal design does not exclude assistive devices for particular groups of disabled individuals when needed.

At this juncture, it is pertinent to introduce the notion of reasonable adjustment, as defined in Article 2.5 of Royal Decree–Law 7/30 October 2015, which endorses the consolidated text of the Land and Urban Rehabilitation Law [31]. “Reasonable adjustment refers to the necessary modifications to a building to achieve universal accessibility effectively, safely, and practically, without imposing an undue burden. The assessment of whether a burden is disproportionate considers the cost of the measures, the potential discriminatory effects of non-implementation, the structure and characteristics of the obligated party, and the availability of official financing or other forms of assistance. A burden is deemed disproportionate in buildings under a horizontal property regime if the annualized cost of the works, minus any public subsidies, exceeds twelve ordinary monthly payments of common expenses” [31].

Furthermore, the same Royal Decree–Law, in Article 2.6, describes the type of dwelling of collective housing buildings as “those composed of several dwellings, which may also include non-residential uses. Buildings designed to accommodate groups of people who, although not a family unit, share services and abide by common rules –such as hotels or residences– are included in this classification”.

2.2. Checklist of Accessibility and Definition of Accessibility Solutions

After analyzing the current legislation on the subject, we have defined a checklist of elements that must be checked to guarantee accessibility at the entrance of the buildings. This checklist is a link between the theoretical study of the regulations and the experimental work carried out in the fieldwork. On the one hand, the checklist is a theoretical support based on the accessibility requirements defined in the legislation studied in Section 2.1, which establishes conditions, measures, and elements necessary in buildings to comply with accessibility. On the other hand, the checklist is a basis on which the fieldwork is based, since it defines step by step all the aspects to be checked, the actions to be taken and the suggested solutions in each situation. The defined checklist for the study of accessibility at the entrance to buildings is shown in

Table 1. Checklist derived from the study of the accessibility regulations and used in the fieldwork.

Question		Action/Comment
What is the difference in level at the entrance to the building?
C1—If there is a height difference, how is it bridged?	C11—By means of a ramp? How wide, long and steep?	Measure the width, slope, and length of the existing ramp at the entrance.
	C12—Does it meet the requirements of DB SUA?	Minimum width: 1.20 m. Maximum slope: - 10% when the length is less than 3 m. - 8% when the length is less than 6 m. - 6% in all other cases. DB SUA and Order of 15 October 1991 required dimensions: - Minimum plateau size: 1.20 m wide × 1.50 m deep. - Height of upper handrail: 90–110 cm. - Height of the lower handrail: 65–75 cm. - Handrail section: 3–5 cm. - Handrail separation from the wall: ≥4 cm. - Dimensions of the protection plinth: ≥10 cm high.
	C13—If it does not meet the requirements of DB SUA, does it meet the requirements of DA DB SUA/2?	Minimum width: 0.90 m free between handrails. Maximum slope: - Up to 3 m with maximum 12% slope. - Up to 10 m with a maximum slope of 10%. - Up to 15 m with a maximum slope of 8%. - Maximum slope of 6% with no length limit. DA DB SUA/2 and Order of 15 October 1991 required dimensions: - Minimum plateau size: 0.90 m clear width between handrails × 1.20 m deep. - Height of upper handrail: 90–110 cm. - Height of lower handrail: 65–75 cm. - Handrail section: 3–5 cm. - Handrail separation from the wall: ≥4 cm. - Dimensions of the protection plinth: ≥10 cm. If not compliant, assess the adaptation of the ramp to meet the requirements.
	C14—By means of a staircase, according to DB SUA?	Measure the staircase and evaluate the construction of a ramp. How high does it rise? Minimum width: 1 m if it complies with the evacuation width according to DB SI. Minimum tread depth: 28 cm. Maximum rung riser: 18.5 cm. No molder plane allowed. Plateau dimensions: ≥1.00 × 1.00 m. Handrail height: 90–110 cm. Handrail section: 3–5 cm. Separation of handrail from wall: ≥4 cm.
	C15—By means of a staircase, according to DA DB SUA/2?	Measure the staircase and evaluate the construction of a ramp. How high does it rise? Minimum width: 0.80 m if it complies with the evacuation width according to DB SI. Minimum tread depth: 28 cm (25 cm if there are up to 8 dwellings). Maximum step riser: 18.5 cm (20 cm if up to 8 dwellings). No molder plane allowed. Plateau dimensions: ≥0.80 × 0.80 m. Handrail height: 90–110 cm. Handrail section: 3–5 cm. Separation of handrail from wall: ≥4 cm.
	C16—By means of a mechanical device? By a vertical lift platform?	Check whether the device complies with the requirements of DA DB-SUA/2. Minimum dimensions of the vertical lift platform, clear of the door sweep: - 80 × 125 cm or 90 × 140 cm (with one or two doors facing each other). - 125 × 140 or 110 × 140 m (with adjacent doors). Minimum calculation load: - 80 × 125 cm: 250 Kg/m2 and at least 250 Kg. - 90 × 140 cm: 250 Kg/m2 and at least 315 Kg. - 125 × 125 cm or 110 × 140 cm: 250 Kg/m2 and at least 385 Kg.
	C17—By means of a mechanical device? By an inclined lift platform (stairlift)?	Check whether the device complies with the requirements of DA DB-SUA/2. Minimum dimensions of the inclined platform lift: - 70 × 90 cm. - 75 × 100 cm. Minimum calculation load: - 70 × 90 cm: 250 Kg/m2 and at least 225 Kg. - 75 × 100 cm: 250 Kg/m2 and at least 250 Kg.
C2—If there is a difference in level saved by a staircase	C21—Can an accessible ramp be built?	Evaluate the possibility of building a ramp according to the requirements of DB SUA indicated in the previous section. If this is not possible, evaluate the possibility of building a ramp with the requirements of DA DB-SUA /2 indicated in the previous section.
	C22—If an accessible ramp cannot be built, can a vertical platform lift be installed?	Measure available space for the installation of the vertical platform lift according to the requirements indicated in the previous section.
	C23—If a vertical lift platform cannot be installed, can an inclined lift platform be installed?	Measure the available stairway width for the installation of the inclined platform lift according to the requirements indicated in the previous section.
	C24—If an inclined platform lift cannot be installed, is it possible to intervene in the public space?	Assess public space, the minimum width of which after the intervention should be greater or equal to 1.80 m.
Is there an elevator to reach the floors?
C3—If there is an elevator	C31—What is the difference in height between the access and the elevator level?	Measure the height difference between the elevator and the access, and how it is bridged.
	C32—If there is a difference, can the elevator be lowered to level 0?	Evaluate the possibility of lowering the elevator to level 0 by means of an intervention in the hallway.
	C33—If not, can an accessible ramp be built to reach the elevator level from the access?	Measure the height between the elevator and the access and the existing length, and evaluate if it is possible to build a ramp according to the requirements of DB SUA indicated in the previous section. If it is not possible, evaluate the possibility of building a ramp according to the requirements of DA DB SUA/2 indicated in the previous section.
	C34—If an accessible ramp cannot be built, can a vertical lift platform be installed?	Measure available space for the installation of the vertical platform lift width according to the requirements indicated in the previous section.
	C35—If a vertical lift platform cannot be installed, can an inclined lift platform be installed?	Measure the available space of the stairs’ width for the installation of the inclined lift platform.
	C36—Is there a garage in the building? Does the elevator reach the garage?	If there is a garage but the elevator does not reach it, study how to connect the elevator to the garage.
	C37—What are the dimensions of the elevator shaft?	Measure the dimension of the existing shaft, to locate the maximum possible cabin size.
	C38—What are the cabin dimensions of the elevator?	Check that it has the following minimum cabin dimension (according to DB SUA): - If it does not have accessible housing for wheelchair users: ○ With one door or two doors facing each other: 1.00 × 1.25 m. ○ With two doors at an angle: 1.40 × 1.40 m. - With accessible housing for wheelchair users: ○ With one door or two doors facing each other: 1.10 × 1.40 m. ○ With two doors at an angle: 1.40 × 1.40 m.
		If the above is not met, check that it has the following minimum cabin dimension (according to DA DB SUA/2): - With one door or two doors facing each other: 0.90 × 1.20 m. - With adjacent doors: 1.25 × 1.25 m or 1.20 m × 1.40 m.
	C39—Does the elevator reach all floors, including the terrace?	If not met, evaluate the possibility of making adaptations to reach all plants.
C4—If there is no elevator	C41—How wide is the vertical communication core?	Measure and check the dimension of the vertical communication core.
	C42—Does it allow the installation of an elevator in common areas?	Check the remaining dimension, as indicated above, after subtracting the minimum stair width.
	C43—If not, does it allow the installation of an elevator in the terrace?	Measure and check the terrace dimension after installing an elevator according to the indicated requirements of DB SUA. If it does not meet the requirements, measure and check the terrace dimension after installing an elevator according to the indicated requirements of DA DB- SUA/2.
	C44—If not, does it allow the installation of an elevator in private areas?	Measure and check the dimensions and frame of private areas after installing an elevator according to the requirements of DB SUA. If it does not meet the requirements, measure and check the dimensions and frame of private areas after installing an elevator according to the requirements of DA DB- SUA/2.
	C45—If not, does it allow the installation of a facade elevator?	Measure and check the dimension of the public space after installing a facade elevator.

.

The adaptations in the buildings that are derived from this checklist are reflected in a series of solutions that must be studied for each case. In order of priority of the actions to be undertaken, the Support Document DA DB-SUA/2 [24] establishes the following accessibility solutions:

• The first solution to be considered is to communicate the lift, if it exists, with the outside space via an accessible route, known as bringing the lift to level 0. An example of this case is shown in Figure 1. The entrance to the building is done via stairs that are completely inaccessible to people with disabilities (as shown in Figure 1a). After the intervention, the entrance level was lowered, so that the elevator was at level 0 (as shown in Figure 1b).
• If this solution is not viable, it is suggested that a ramp is placed in accordance with the conditions of the DB SUA or, if this is not possible, in accordance with the tolerances of the Supporting Document. Figure 1d presents an example of this case.
  These first two are the best solutions, since both are integrated options that aim to achieve the highest level of accessibility for the common areas of collective housing. In addition, these options can be applied to all users of the buildings, regardless of whether they have disabilities or not. They will, therefore, be the preferred options in the fieldwork.
• As a third level, the Support Document considers the installation of a vertical lift platform. This vertical platform serves to bridge the difference in the level of the entrance stairs within the private space of the building, giving access to the elevator.
• As a last option, the Support Document proposes the installation of an inclined lifting platform (stairlift) in marginal cases where the other options cannot be adopted. An example of this situation can be seen in Figure 2a, where a lift platform was placed to lead to the elevator.
  Options 3 and 4 are acceptable options, but they are only usable by people with disabilities. This means that the mentioned concepts of integration, equality, etc., are not followed. In any case, in some cases it is necessary to resort to them.
• In those cases where the accessibility cannot be resolved within the boundaries of the private space in any of the above options, the Support Document proposes the occupation of the public space, taking the necessary measures to guarantee the safety of the public space. An example of this situation can be seen in Figure 2b,c, where a ramp is planned to be placed on the sidewalk at the entrance to the building.
• In situations where other alternatives are not possible, the support document also considers the installation of motorized rails or chair saving stairs. The present research does not consider this option as an alternative. In the field work, a solution between the first five approaches is always selected in order to guarantee the autonomy of people with disabilities.

With regard to the criteria for the installation of lifts in blocks of flats, the Supporting Document establishes an order of priority, in this case based on the legal difficulty of implementation. The installation of the lift in the internal common areas is considered the first option; next, the installation on the interior courtyards and the facade of the building; and finally, in the private areas. Some examples of these cases are presented in Figure 3.

According to the above criteria, the following options have been identified: the lift to level 0, internal inclined plane (4%), internal filler, internal ramp, vertical lift platform, inclined lift platform, ramp in public area, lift in common areas, lift in internal terraces, external lift, and lift in private areas. It should be noted that, in Spanish legislation, the concepts of an inclined plane and ramp are not equivalent. According to Art. 4.3 of DB SUA [24], an itinerary in general use whose slope is more than 4% is considered as a ramp. Those itineraries with a longitudinal slope of less than 4% are not considered as a ramp and can be assimilated to a horizontal surface, always provided that the direction of travel is clearly defined; henceforth, we refer to them as inclined planes.

2.3. Cost Analysis of the Proposed Accessibility Solutions

The cost analysis of accessibility solutions is a fundamental aspect to take into account, since it can determine the ability of a building’s community of neighbors to undertake the works or not. Therefore, public policies to promote accessibility should be aware of this aspect, offering financial aid programs for adaptation works, with special attention to the most costly actions when the less costly ones are unfeasible. Obviously, the cost of the 11 proposed solutions cannot be determined precisely, since it depends on the specific characteristics of each case. For example, in the case of a ramp, it depends on the length of the ramp; in the case of an elevator, it depends on the intervention to be carried out, the number of stops, etc. In addition, the geographical factor can have a decisive influence on costs, since prices are not comparable from one country to another, or even from one city to another. And it is well known that over time, the prices of goods and services are highly variable. Finally, the number of inhabitants of the building determines proportionally the cost of the works that can be assumed.

Thus, the cost analysis has been performed on an approximate and averaged basis, with a classification into two categories: low and high. The determination of the limit between categories has been made taking into account the Spanish Public Sector Contracts Law [32], which in Article 118.1 establishes that actions under 40,000 EUR of an estimated contract value are considered minor works, and those above that limit are major works. With this limit as a reference, the proposed actions can be classified as:

• Low-cost actions (less than 40,000 EUR): internal inclined plane (4%), internal filler, internal ramp, vertical lift platform, inclined lift platform, and ramp in public areas.
• High-cost actions (more than 40,000 EUR): lift to level 0, lift in common areas, lift in internal terraces, external lift, and lift in private areas.

2.4. Description and Design of the Field Work

The objective of the present work is not limited to a study of the current accessibility regulations. It has been complemented by extensive fieldwork in which the entrances to 150 collective housing buildings in the Region of Murcia, in the southeast of Spain, have been analyzed. The purpose is to analyze the current situation of these buildings in terms of accessibility, in order to verify the degree of compliance with the regulations. In addition, for all the buildings that do not comply with the regulations, a detailed proposal of possible solutions to adapt the entrances to the regulations has been carried out. In this way, the aim is to analyze the cost of making the necessary adaptations to achieve the objectives of universal accessibility.

The Region of Murcia has been taken as a case study of interest for the present work. Murcia is a medium-sized region in southeast Spain (with more than 1,531,000 inhabitants, according to the 2022 census). Most of the present study has been carried out in the capital of the region with the same name. It represents a unique case study due to its sizeable elderly and disabled populations, with 15.8% of people over 64 years of age [33] and an estimated 9.8% of people with disabilities among the population of the Region of Murcia [34]. This demographic context, combined with the region’s common architectural form of large housing blocks, offers an ideal setting for exploring the challenges and opportunities of building accessibility [35]. In fact, it is as a typical example of European architecture, whose buildings span a wide range of decades, the most numerous being between the 1970s and the 2000s. The selection of the buildings started from the owners who had identified a problem of accessibility in their building, so they contacted the architect who developed this research.

The selected buildings are located along the Region of Murcia, in the followings cities: Murcia (79 buildings), Molina de Segura (19), Blanca (11), San Javier (10), Cartagena (8), Alcantarilla (7), Mazarrón (4), Cieza (2), Santomera (2), Yecla (2), Abarán (1), Alguazas (1), Fuente Álamo (1), Jumilla (1), Lorca (1), and San Pedro del Pinatar (1). The visits took place between November 2009 and March 2022. This long time period shows that this research is the product of many years of development and study in this area. Figure 4 presents a map of these locations.

During the visits of the field work, the architect measured the entrance of the buildings, took photographs, and analyzed the existing barriers. Then, he tried to get the plans of the original project and, in some cases, it was necessary to make some proofs where the works should take place in order to check the real composition of the existing buildings. With all this information, the architect studied the best option according to the existing rules and according to his working experience.

The analysis not only focuses on the most common solutions among the proposals, but also allows us to know a fundamental aspect, namely the percentage of cases that require not only one, but two or even three interventions to achieve the effective adaptation of the accessibility conditions. This aspect has been deepened by analyzing the mix of cases requiring two or three interventions to improve accessibility.

We must also take into account the interaction between the rules to be followed in the estate and in the local area, which have an impact on technical matters (DB SUA and Support Document) and aspects of the Law on Land and Urban Renovation [25], which have an impact on the occupation of public space.

3. Results

This section presents the results of the field work, as well as the analysis and discussion of the obtained information. It should be recalled that the work was carried out on 150 buildings, all of which required an accessibility solution since the process was started by a request from the owners.

After a detailed analysis of the information obtained from each of the buildings visited, the architect in charge of the study proposed the best accessibility solution for each case. This could include the adoption of one, two, or three actions among those described in Section 2, i.e.,: (1) a lift to level 0; (2) an internal inclined plane (up to 4%); (3) an internal filler; (4) an internal ramp; (5) a vertical lift platform; (6) an inclined lift platform; (7) a ramp in public space; (8) a lift in common areas; (9) a lift in internal terraces; (10) an external lift; and (11) a lift in private areas. The total percentage of accessibility solutions required for the 150 buildings is shown in Figure 5, ordered from the highest to lowest frequency.

Figure 5 shows that in 40.67% of the cases studied, the improvement of accessibility conditions takes place through the construction of a ramp in the entrance corridor of the building, either as a single solution or as a complement to other solutions. In addition, in 11.33% of the cases, the construction of an inclined plane was proposed, which occurs when the slope is 4% or less. Solutions with a ramp are almost four times more frequent than those with inclined planes. The next most common solutions are the installation of a vertical lift platform in 29.33% of cases, the construction of a ramp in the public area in 21.33% of cases, bringing the lift to level 0 in 19.33% of cases, and the installation of an inclined lift platform in 16% of cases.

In the opposite end, we can find the least common solutions as being filling inside the hallway in 1.33% of the cases (two buildings), installing a lift outside the building in 2.67%, installing a lift in an interior terrace in 3.33%, installing a lift in private areas in 5.33%, and installing a lift in common areas in 8.67%.

Considering the cost analysis, the three most common solutions are among those classified in the lowest-cost category, while those involving the installation of an elevator in public areas, private areas, facades, or terraces are among the least frequent. Only the more expensive solution of bringing the lift to level 0 ranks in the top four. In general, this can have beneficial implications, since the most frequent solutions are usually the least costly.

Of the total number of buildings studied, in 43.3% (65 cases), a single solution was proposed to achieve accessibility, while in 54% (81 cases), two actions were required, and in 2.67% (four cases), three actions were required to achieve accessibility at the entrance to the building. The disaggregated results for the cases where one or two actions were required are shown in Figure 6 and Figure 7, respectively.

The analysis of Figure 6 shows that in the 23% of cases resolved by an option (i.e., 10% of all cases), the solution to resolve accessibility is to install a vertical lift platform in the corridor. The following most appropriate options are the construction of a ramp inside the corridor in 20% of the cases (8.67% of all cases), bringing the lift to level 0 and the installation of an inclined lifting platform. On the contrary, the infill inside the corridor is not proposed as a unique solution, although it appears as a complement to other solutions, as we can see in Figure 7. Again, in general, the most frequent solutions are those that require less cost.

This study shows that the most repeated accessibility option with the mix of two options is an interior ramp and a vertical platform lift in 17.28% of the cases classified with two solutions (14 cases). The following most common options are a vertical lift platform and ramp in a public space and a vertical lift platform and ramp in a public space (both in 11.11% of cases), an indoor ramp and ramp in a public space in 9.88%, and an inclined lift platform and ramp in a public space in 7.41%. In general, the combinations are very spread out, which means that the typology and problems of the buildings are very varied. It is not possible to reduce the accessibility study to a few cases, but each building will require a specific project. Moreover, it should be recalled that in 4 of the 150 buildings, three solutions were needed to achieve accessibility.

Finally, Figure 8 represents the percentage of buildings analyzed according to the decade of construction, ranging from 1932 to 2005. After investigating the buildings according to their age, we can see that most of the buildings with accessibility needs were built in the decades 1981–1990, with 37.33% of the buildings studied, and 1971–1980, with 31.33% of the buildings studied. However, this figure should be put in comparison with the number of existing buildings for each decade.

Figure 9 compares the proposed accessibility solutions with respect to the age of the buildings. In particular, the buildings were classified into two categories: the oldest (up to 1980) and the most modern (from 1981 onwards).

As could be expected, the oldest buildings are usually the ones that require the most costly interventions. Thus, while the ramps and the vertical lift platforms are more frequent for more modern buildings, solutions involving the installation of elevators are more frequent in older buildings. This finding can have important implications in public policies to promote accessibility, which should take into account the higher costs of adaptation for older buildings.

4. Discussion

The ultimate objective of quality in housing construction must be to respond to the growing social demand for quality and accessibility through the basic requirements that spaces must meet in order to guarantee the safety of people, the welfare of society, and the protection of the environment. First of all, it should be emphasized that the existence of people with motor or sensory disabilities requires the design and construction of solutions that guarantee general accessibility in urban spaces and buildings, both in public and private. The need to use mechanisms that allow the displacement of people with locomotor difficulties, such as wheelchairs, or devices to assist people with sensory disabilities, such as the blind, requires that the conditions of the design and execution of the different itineraries or spaces meet a series of requirements that make effective the possibility of use by people who need it, and with the highest possible degree of autonomy.

The results of the field work show the need for more than two solutions of accessibility in more than half of the cases studied (56.6%), and even three solutions were required in several cases. This fact brings to light that we have to consider the chain of accessibility because, in this percentage of cases, if only one solution is adopted, the itinerary will not be complete, and obviously it would not be an accessible itinerary.

It must be insisted that the solution to the problems that may arise to solve accessibility in general requires that the design and execution conditions be really effective, that is, they must comply with the conditions that are established, but at the same time an effective solution must be required in the final complete result, since the slightest rupture makes the purpose for which it is intended impossible. This is why it is crucial that accessibility problems are solved in an integral manner and not only and exclusively through the accumulation of regulated solutions. This is what has come to be known in the field of accessibility as the “accessibility chain”, which establishes that all the links of the itinerary from the public space to the access to the dwelling must be accessible, since the slightest interruption would mean that the rest of the elements that make up this itinerary would not meet the requirement for which they have been designed.

The conditions to be applied, through the regulation in question, must have the highest degree of effectiveness, enforceability, guarantee of application, categorization, and be able to really solve what is intended, as well as allowing a solution to those existing situations that, due to their characteristics, do not allow the application of the conditions set for the actions to be taken up from the conception of the project in their entirety.

At this point, it is necessary to mention that the DA DB-SUA/2 [24] does not specify those cases, which are otherwise common, in which more than one action must be taken to solve accessibility. But not only that, it also does not mention those also frequent cases in which at least more than one of the proposed solutions can be adopted and all of them are within the limits established in Article 2.5 regarding the definition of “Reasonable Adjustments” of the Law of Land and Urban Rehabilitation [31]. In this case, priority should be given to those actions that, although more costly, improve accessibility conditions, as long as they are within the reasonable adjustments defined in the aforementioned article. On the other hand, Article 24.4 of the Law on Land and Urban Rehabilitation does not establish the limits beyond which an action ceases to be a “reasonable accommodation” in a private space in order to be developed in a public space.

The age of the buildings that need to adapt their accessibility conditions is due to technical and sociological factors. On the one hand, the age of the people who bought these houses in the decades between 1971 and 1980 and 1981 and 1990 has increased to the point that they have problems of mobility and require the adaptation of the common areas in their buildings. Moreover, we must add that the first local regulation in the Region of Murcia regarding accessibility was published in 1987, through Decree 39/1987, followed by the Order of 15 October 1991. This justifies that almost 70% of the buildings that required solutions of accessibility were built in the period 1971–1990. Consequently, public aid for accessibility adaptations should at least cover buildings constructed before 1991, taking into account that the oldest building will normally require more expensive interventions.

5. Conclusions

Accessibility is a fundamental right for all individuals, regardless of their disability status. This is particularly crucial at the entrances of collective housing buildings, where accessibility impacts daily life. As our society continues to age, the proportion of the population with mobility issues is expected to increase, further emphasizing the need for accessible infrastructure. The present work contributes to fill the gap of previous studies, mostly dedicated to public buildings, and to where the relationship between the problems detected and the solutions to be applied is lacking.

Our study, conducted in the Region of Murcia, Spain, has combined a thorough review of the relevant regulations with detailed fieldwork across 150 residential buildings. Our findings reveal that a significant majority of these buildings (56.6%) require multiple interventions to ensure full accessibility. The most frequently needed adaptations include the installation of vertical lift platforms, internal ramps, and adjustments to bring elevators to ground level. Older buildings usually require the application of more costly solutions; in many cases, the installation of elevators. However, in newer buildings, the solutions are usually less expensive, such as the construction or adaptation of ramps. Often, these modifications need to be complemented with other specific actions, underscoring the necessity for customized accessibility solutions tailored to each building’s unique context. This variability highlights the importance of involving architects specialized in accessibility to conduct comprehensive assessments of each situation.

Looking ahead, it would be beneficial to extend this research to other geographic areas to broaden the applicability of our conclusions and to further inform public policies. It is crucial that policymakers recognize the ongoing issue of inaccessible residential buildings, particularly those constructed before the 1990s, and consider providing financial support or incentives to facilitate necessary modifications. Such initiatives would not only improve accessibility, but also enhance the quality of life for individuals with motor disabilities.