Urban interventions in historic districts as an approach to upgrade the local communities

ABSTRACT The historic districts keep many elements of tangible and intangible heritage, including planning patterns, historic buildings, social networks, lifestyles, traditional crafts, skills, inherited customs and traditions, ceremonial rituals, and appearances. All of that forms unique configurations that express the identity and collective memory of cities. However, in light of the expansion of cities and the accompanying urban transformations, these districts often witness a significant deterioration due to their loss of the higher income groups of their indigenous inhabitants, which leads to a decrease in their economic vitality and level of performance and the deterioration of the residential inventory and living environment in them in general. That is consequently reflected in their resources, even leads to weakening the possibilities of investing it culturally and economically. Therefore, in most countries of the world, these districts have been the focus of many interventions. The early efforts of such interventions were aimed mainly at the conservation of landmark monuments. Later, the scope expanded to include physical, social, economic, and environmental contexts. Because of the importance of this issue, this paper deals with examples of urban interventions in the historic districts of the Arab region, include the projects of El-Hafsia, Tunis, and Al-Darb Al-Ahmar, Cairo, in order to propose reference bases for upgrading the local communities of such districts.


Introduction
Historic districts in cities are a living embodiment of peoples' cultures and their collective memory that preserves their heritage and past achievements. As such districts maintain the invisible social networks that explain how generations relate to each other and their urban environment, also support a sense of moral and esthetic values that inspire and influence human behavior. Therefore, they are not static structures, rather work to support identity-building processes that are vital to strengthening civil society. So contemporary cities still rely on their historical centers as sources of cultural identity [1]. Hence, urban conservation should not be limited to saving the physical structures; but must also help to the persistence of social patterns, or in other words, how to keep cultural traditions alive; and how to help them thrive under the changing conditions. Therefore, focusing on the physical structure of historic cities is usually not sufficient without taking into account the cultural processes that have produced such a unique urban fabric that can be sustained and revived. So the core values of historic cities cannot be preserved static but must be revitalized to become operable again under changing external conditions. As the historical monuments and archeological sites must be preserved, re-adapting them is often a convenient way to make them meaningful again. But the real dilemma is that conserving the spirit of a historic city inhabited by living communities is usually more complicated unless the daily needs and the deeper aspirations of its inhabitants are taken into account.

Contemporary intellectual transformations of heritage issues
Over the course of a century and a half, the idea of conserving the urban heritage has evolved in a way that has radically changed the traditional concepts of conservation. Many international organizations and institutions have been interested in developing conservation thinking and methodologies. That was reflected in the international charters and recommendations that formed the basic principles for conserving heritage in most countries and the related vital urban issues. The protection of cultural heritage assets for a long time has focused on preserving and restoring monuments. Although this has contributed to preserving many historical buildings and sites, it has created difficulties related to heritage, urban concepts, and evolutionary processes. It also did not provide the appropriate framework for assessing the intangible features associated with heritage. Besides, focus on conserving the heritage properties and protecting them with the slightest change has made the conservation take a position opposing the development [2]. However, since the 1960s, the idea of an integrated and comprehensive approach to heritage and urban development began to be highlighted in the relevant international documents, as there was an increasing emphasis on the importance of striking a balance between the benefits of social, economic, and urban development on the one hand, and the conservation of cultural heritage on the other. The Venice Charter stated that the conservation of historic buildings should be to benefit society and to the need to link cultural monuments with their natural settings [3].
Later, during the 1970s, cultural heritage management began to move toward a more comprehensive approach that also included intangible concepts, with greater attention paid to the social and economic functions of urban heritage. This approach was defined as the landscapebased approach, including everyday ordinary scenes, as the first trends to integrate urban heritage into planning programs also emerged. This content has been confirmed through several international documents, the most important of them is the UNESCO Recommendation concerning the Safeguarding and Contemporary Role of Historic Areas (1976 Nairobi Recommendation), which emphasized the need to integrate historical areas in harmony with the life of contemporary society as a fundamental factor in town planning and land development, with an emphasis on the continuity of human activities in historical areas, no matter how modest, including traditional living patterns and handicrafts, on par with the protection of buildings and comprehensive spatial organization [4].
In the 1980s, the Charter on the Conservation of Historic Towns and Urban Areas (the Washington Charter 1987) was adopted to promote harmony between private and community life in these historic districts and encourage the conservation of cultural properties, however modest in scale, that constitute the memory of mankind. As well as consider that the goal of conserving historical cities and urban areas is to protect, conserve and restore them, as well as to develop and adapt them harmoniously with contemporary life. This charter also emphasized more clearly that conservation should be an integral part of development policies and socio-economic planning at all levels [5].
With the beginning of the second decade of the current century, due to pressures and changes related to human settlements in general and historic towns and urban areas in particular, and as part of the attempts to enhance identity, the management of change in historical districts took a more clear direction. So the Valletta principles were adopted for the safeguarding and management of historic cities, towns, and urban areas in 2011, as an update of the approaches and considerations contained in the Washington Charter (1987) and the Nairobi Recommendation (1976), which mainly aimed to suggest principles and strategies for interventions in historical cities and urban areas to conserve their values as well as integrate them into contemporary social, cultural and economic life, and to ensure life quality for their residents. These principles reflect an awareness of historical heritage on a regional scale and intangible values such as continuity and identity, as well as the role of public spaces in community interactions more than before. It also takes into account the problems of large-scale developments and considers the heritage as an essential resource and a part of the urban ecosystem [6].
As a general principle, this document specified that change 'must be an opportunity to improve the quality of historical cities and urban areas based on their historical characteristics when properly managed'. That includes subprinciples covering four areas of change: the natural environment, the built environment, the social environment, and intangible heritage (Figure 1), emphasizing that such changes must be governed by criteria for intervention in heritage areas, including [6]: (1) Values: All interventions in historic cities and urban areas must respect and refer to tangible and intangible cultural values. (2) Quality: Every intervention in historic cities and urban areas should aim to improve the quality of life of residents and the quality of the environment. (3) Quantity: Major quantitative and qualitative changes should be avoided unless they clearly improve the urban environment and its cultural values. (4) Cohesion: The protection of historic cities and urban areas must be an integral part of a general understanding of the urban structure and its surroundings. (5) Balance and Compatibility: It should include the maintenance of basic spatial, environmental, social, cultural, and economic balances. (6) Time: Excessive speed of change can negatively affect the integrity of all historic city values, so the frequency and consistency of the intervention must be included with feasibility studies and planning documents. (7) Methodology and scientific discipline: The protection and management of a historic city or urban area must be guided by a systematic approach, a deep knowledge of the site and its context before any protection measures, and constant monitoring and maintenance.
With the necessity of direct consultation and continuous dialogue with residents and stakeholders. (8) Governance: Good governance involves broad organization among all stakeholders, so measures to protect historic cities must provide sufficient information and time for residents to provide informed responses. (9) Multidisciplinary and Cooperation: The protection of historic cities must be based on effective cooperation between different professionals with researchers, private institutions, and the wider public. (10) Cultural Diversity: The cultural diversity of the different societies that have inhabited historic cities overtime must be respected. With the necessity of establishing a sensitive and common balance in order to preserve their historical heritage.

Contemporary trends in urban interventions
The types of urban interventions in historical districts differ according to the situation of their urban fabric and the economic, social, and environmental contexts. Urban Regeneration is one of the important practices in urban intervention policies that deal with deteriorating urban districts that accompanied by poor environmental, social, and economic conditions, to adapt their urban structure and make them conform to the modern requirements of individuals and societies depending on the available economic and technical capabilities [7]. It shares similar meanings with Urban Renewal, Urban Redevelopment, and Urban Rehabilitation, especially in terms of scale. While the meanings of Urban Regeneration and Urban Renewal are similar in that they are both related to relatively large-scale interventions compared to Urban Redevelopment which is done on a more specific scale and usually targeting profitability [8]. On the other hand, Urban Rehabilitation aims basically to restore the condition of a building or group of buildings into good condition [9]. Whereas Adaptive Reuse refers to utilize buildings for new purposes that respect their significance, heritage values, and add a contemporary layer that gains them new values for the future [10].
Although urban interventions are usually adopted for dealing with changing urban environments in order to overcome the problems of urban degradation and meet various social and economic goals, practical practices in different parts of the world often have shown side effects such as social problems resulting from the destruction of existing social networks, exclusion of vulnerable groups in local communities, and other negative side-effects of development on living environments [11]. That has stimulated a more effective approach, as more recent urban intervention approaches have evolved and become increasingly linked to concepts such as sustainability, property values, promoting entrepreneurship, as well as attracting private investment. From this viewpoint, the urban intervention has come to be seen as linked to the sustainable development agenda and must address physical, social, economic, and environmental issues together in an integrated framework [8]. To ensure the sustainability of urban interventions, it is necessary to consider the different needs and expectations of different current and future generations, including meeting functional and esthetic needs, designing buildings and public spaces in order to create a high-quality and sustainable urban environment. Many previous studies such as CABE [14] have endorsed that the positive effects of sustainable urban interventions can bring many benefits to societies such as stimulating investment opportunities, increasing productivity, creating job opportunities, enhancing social inclusion, providing amenities, and improving the quality of life.
Heritage-led Urban Regeneration is also considered one of the preferred interventions to improve the condition of dilapidated historic districts, as it involves reviving degraded assets, developing their future potential, and working to integrate the historical environment into contemporary life. It expresses a comprehensive and integrated vision that leads to solving urban problems and seeks to achieve permanent improvement in the economic, social, and environmental conditions of a district that has undergone a change [15].
On the other hand, many practices emphasize the cumulative impact of such heritage investments, as the Heritage-led Urban Regeneration concept reinforces six elements of investments that support conservation, including property, land, capital, human resources, heritage resources, and political commitment. It is also believed that the urban renewal of historic areas supports the quality of the districts as a whole since the proceeds of regeneration can provide the capital needed for further conservation activities, such cycle is an example of a heritage-led sustainable urban regeneration model. The restoration of cultural assets by local communities is usually becoming a catalyst for economic development because direct employment opportunities for workers and craftsmen living in the old districts are enhanced. Besides the facilities that are renewed also may become a factor of tourist attraction which generates more opportunities. As residents of such areas enjoy new income sources, they may direct some of them to improve their homes and districts. So that is one of the pragmatic reasons for revitalizing the cultural assets of societies [16]. Heritage-led urban regeneration as one of the policies that emphasize the integrated treatment of historic urban areas raises several critical issues related to political, cultural, social, economic, urban, and environmental aspects; As follows: • Political aspects: How can political support be generated and sustained?
How can national policies be created to support urban heritage conservation and restoration? • Cultural aspects: To what extent can the renewal of historic residential districts enhance traditions and indigenous cultural forms? What is the role of historical districts and their physical and social characteristics in local (or national) culture? Could these districts gain a special tourist significance? • Social aspects: How can the poor, who often make most of the inhabitants of the historic districts, participate effectively in the regeneration process? How can low-income residents be sustained in the face of landuse changes? Or how to support them when it is difficult to keep them? How can low-income residents be protected from the side effects of regeneration? • Economic aspects: How can urban renewal be financed? What mix of private and public resources or public-private partnerships could be used? What is the impact of rising real estate and land values and/or taxes? What is the economic role that tourism can play in this context? • Urban aspects: How can the identity and spirit of historic districts be preserved in the face of changes associated with the renewal and landuse change? Can the historical quality of such mixed-use environments be adapted to modern conditions? • Environmental aspects: How can urban regeneration affect the natural environment? What are its potential impacts on ecosystems? • To discuss these questions, related issues will be addressed by studying and analyzing models of urban interventions in historical districts in the Arab region.

Models of urban interventions in historical districts
Many historic cities in the world have applied multiple approaches to urban interventions in their historic districts in order to preserve their heritage assets and enhance their identity. For the purpose of formulating a reference basis for such interventions through which local communities can be upgraded, the experiences of El-Hafsia, Tunis, and Al-Darb al-Ahmar, Cairo were chosen as models of urban intervention practices in historical districts through them can analyze the most important related issues, the criteria for this selection included: • Cultural background: both experiences express the culture of Arab cities and their Islamic identity. • Geographical area: both of them are located in the Mediterranean region. • Economic conditions: two experiences expressing the economies of developing countries. • International and regional recognition: both experiences have international and regional repercussions. • Social orientation: both give special attention to local communities.

General context
Under the rule of the Almohads and Hafsids, Tunis was one of the greatest and richest cities in the Arab world. Later, the Ottomans added many buildings and facilities to it between the 16-19 centuries [17]. Under the French occupation in 1881, the modern city extended beyond the walls of the old Arab city that had been marginalized, in the early twentieth century, a circular road was constructed instead of the old walls to merge the modern and old cities [18]. Later on, the old city was internationally recognized for its exceptional value when inscribed on the World Heritage List in 1979 [19].
El-Hafsia quarter is the former Jewish quarter of old Tunis, which is located to the east of its center, it is characterized by the traditional style of narrow alleys and courtyard houses, but its esthetic and historical value is not as high as the rest of the old city ( Figure 2). During the colonial period, its indigenous inhabitants began to move to the new European districts, in 1928 the French authorities declared the quarter a danger to public health, so many of its buildings were demolished between 1933 − 1939. There was also more destruction due to the bombing of the city during World War II. In the following years, some constructions had taken place, then demolitions took place again during the 1960s, whereas the poor immigrants settled in the remaining abandoned houses, causing further deterioration of the Historic quarter [20].

The background of urban interventions in Hafsia
After the independence of Tunisia in 1956, the municipality of Tunis had plans to develop the city with huge projects. In 1960 a massive movement took place to remove the slums in El-Hafsia, where two schools, a clothes market, a children's club, and a social services center were built without taking into account the traditional street networks. But with the commencement of the demolition of the Sidi-Bashir neighborhood in 1967, a popular revolution occurred that led to the abandonment of the new projects and establishing the Association for Safeguarding the City (ASM) under the auspices of UNESCO and the municipality of Tunis for conducting comprehensive multidisciplinary studies that help to direct future planning efforts in the Old City and improve the living conditions of its residents as a basis for Hafsia 1 project (1972Hafsia 1 project ( -1977, which was the catalyst for a more comprehensive and broader intervention (Hafsia 2 project 1985-1992), which was undertaken in the context of the Third Urban Project with partial funding from the World Bank ( Figure 3).

El-Hafsia project 1
ASM prepared the outlines for reviving El-Hafsia quarter based on a socioeconomic survey that began in 1972, which include a study of cultural background, income level, and requirements of expected population related to housing size, design, and required stores. The works in this phase included three basic components: rebuilding Al-Hout covered market with about 100 stores, building 95 housing units on vacant lands in the traditional courtyard style for low-income families, and establishing 22 professional offices, with preserving street patterns. This project was implemented at an estimated cost of 3.7 million USD [21] (Figure 4). This project has able to maintain a harmonious relationship with the existing urban morphology by merging the new buildings with the old fabric and providing a variety of irregular organic forms of courtyard houses and bridge houses matching the traditional street style as well as supporting commercial activities. However, the new houses remained scattered among dilapidated buildings and abandoned land areas that were confiscated by the Tunis municipality and remained shelter for the homeless and street vendors. On the other hand, the goal of providing adequate housing for the poor was not achieved due to regional inflationary trends in the 1970s that led to an increase in construction costs by 121%, in addition to raising housing standards in a way that exceeded the capabilities of most residents whose average monthly income was 33 USD, while the cost of obtaining dwelling necessitate down payment and monthly installments of 30-60 USD for 20 years. Because of this disparity, the indigenous inhabitants were excluded and a large proportion of the new residents came from wealthier social sectors [19]. Although Hafsia 1 was unsuccessful in achieving many social goals, it's winning of the Aga Khan Award in 1983 was due to its ability to stimulate a new commercial and residential life in a previously deserted area, as well as it was a transitional catalyst toward a new way of designing urban renewal projects.

El-Hafsia project 2
The reconstruction program for the second phase of the Hafsia quarter was launched as one of the components of the third urban project funded by the Tunisian government with the participation of the World Bank. Accordingly, in 1981-1982 the ASM submitted a proposal for another phase of low-income housing in the quarter in coordination with the municipality of Tunis and the Urban Rehabilitation and Renovation Agency ARRU. The overall objectives of this project included [23]: • Preserving the historical character and cultural heritage of the quarter. • Implementing a comprehensive program for the reconstruction, rehabilitation, or renewal of the residential and commercial sectors, with attention to maintaining harmonious relations with the traditional urban fabric. • Developing the institutional and financial arrangements to activate a reconstruction program that takes into account the capabilities and needs of the inhabitants. • Taking into account previous efforts that aimed to restore the vitality of the quarter via improving the urban environment and living conditions.
Within the framework of these objectives, the functional requirements of the project included three basic components: (1) the infrastructure, which includes the supply or improvement of facilities and development of the road network and services (2) the rehabilitation, which includes development and restoration of degraded housing in an appropriate manner (3) the reconstruction including construction on the abandoned municipality land and the sites that were demolished, the construction of social housing, private sector housing, commercial uses, offices, parking lots and public services ( Figure 5). In 1981, intervention areas of 13.5 hectares were identified, as the social survey showed that 711 families in the Sidi Younes and Sidi Baiyan neighborhoods live in poor conditions, lacking basic infrastructure, and with high crowding rates amounting to about 5-6 people/room [19]. The new intervention was envisioned as an urban component linking the interventions that took place in Hafsia 1 with the Sidi Younes and Sidi Baiyan neighborhoods ( Figure 3). It consists of a combination of renewal and rehabilitation, including the construction of 400 new housing units and the rehabilitation of 600 old ones, to achieve urban harmony between the areas being renewed and the old fabric. Within the framework of the project, the old building lines have adhered. ِ Also the variety of house types were developed to suit small land areas and to meet the requirements of low-income people. So that many residential buildings were constructed as a continuation of the existing buildings that were rehabilitated on the site of the old ramparts encircling the city, as well as new courtyard-houses were built, most of which could be divided into two dwellings. The sizes and styles of the traditional buildings were also respected, and the height of the housing lies on the main roads was limited to three floors, while the maximum height was two floors for the housing lies on the alleys [23]. The traditional vocabulary was used for new buildings but was simplified to suit the limited budget and simple technology construction methods that could be implemented by unskilled local labor as an additional social aspect, while heritage restoration work was carried out by skilled craftsmen [21]. The Hafsia II project also has won the Aga Khan Award for Architecture in 1995 for its originality and pioneering achievement in bringing two issues together namely: socially, rehabilitating housing for lowincome families, and culturally, conserving heritage assets and integrating them into contemporary life [19].

Financing
The Hafsia I project was fully funded by the government, with a total cost of about 3.7 million USD, more than half of which was allocated for residential projects (Table 1). According to cost-recovery principles, every homebuyer makes an initial down payment and compensates the remaining balance as a monthly rent depending on the house type. The shops were not sold but given to the municipality to be rented out as compensation for the value of the land, thus the entire process is somewhat self-financing [20]. While the total costs of the Hafsia II project amounted to about 12.5 million USD, with the participation of the World Bank, amounting to 2.8 million USD. A preliminary assessment by the World Bank in 1992 estimated project revenues at about 13.5 million USD, providing a surplus of 1.0 million USD, as land and property sales provided the cross-subsidy for the rehabilitation component [19]. (Table 2).

Impact on the local community
Job opportunities: The project contributed to providing new job opportunities in the quarter, as the employment resulting from the project was estimated at 2,200 jobs, including formal construction, construction support services, small projects, and the supply of goods and services. About 44% of these opportunities were in occupations requiring low skill levels.
Facilities and services: The project included the construction of 5,350 m2 of retail shops and small hotels, 4,150 m2 of offices, and 6,130 m2 of social services that included a nursery school, public bathhouse, clinic, youth club, and a covered car park, in addition to paving 3 km of local roads [24].
Housing: Social solidarity was considered one of the most important aspects of the second phase of the project to avoid previous deficiencies in the housing program. Therefore, the incoming wealthier residents had to pay a higher share of the costs for reducing the exclusion of the poor who already live in the quarter. Besides, 600 rehabilitated housing units were exempted from real estate tax as an incentive to keep their residents, also 120 new units were exempted in the sector that was renovated to make them available to low-income residents. While the rest of the new units in the renovated sector, shops and offices, were subjected to a real estate tax that covers the costs of facilities, roads, and compensation for evicted residents. On the other hand, the remainder of the land was auctioned off to private developers who were allowed to build middle-class housing up to three floors under ASM's design principles and sell them at market prices, to provide additional sources to finance the rehabilitation of old housing [19]. To facilitate the benefit of low-income people from the Hafsia II project, minimum housing standards have been adopted. Rents were also set at 18% of the monthly income of those suffering from extreme poverty, while monthly payments were set at about 22% of the household income for those who opted and qualified to buy. The cross-subsidizing strategy of lowincome social housing with high-income housing in the private sector allowed the project to sustain itself financially and secured the availability of affordable housing. According to ASM, out of 134 families who were directly affected by the demolition and new construction, two-thirds of them did not qualify to buy houses, 23 of them were re-housed in rental units inside Hafsia, and the remaining 65 families resettled in subsidized housing outside the quarter [18].
Associated environmental impacts: Although the urban interventions in the Hafsia did not add significant green spaces, except for the residential yards and courtyards, the project in its two stages, was able to get rid of the physical and visual pollution hotspots that were caused by the presence of ruins in the area over decades ( Figure 6). On the other hand, environmental requirements were taken into account in the design of traditional houses in terms of providing lighting, natural ventilation, shading, and protection from winds, which helped to provide a good residential environment [20] [23] .

Project sustainability
It was observed early that the rehabilitation of the old city needs a longer implementation period than the time frame for the regular development projects, so the tendency has directed to strengthen the institutional framework to ensure the continuity of achievement. The Urban Rehabilitation and Renovation Agency ARRU was established as an implementation unit to develop technical expertise for project management and to ensure the effective participation of owners and tenants. Innovative land-use planning mechanisms have also been introduced and the procedures have been simplified to enhance economic activities and maximize project development potentials by stimulating the influx of private investments, which enabled the government to cover project costs including resettlement of the displaced inhabitants and support the housing for low-income residents (See Table 2).
After the project completion, the evaluation study showed that the land use mechanisms established by the government with the support of the World Bank added construction on lands of 73,560 m2, in addition to the directly funded construction. These new mechanisms remained in effect even after the completion of the project. Furthermore, within the framework of the project, a credit mechanism was established with the participation of owners and tenants to improve housing, as borrowing procedures were simplified and access to credit was opened to the residents of the city as a whole, including its traditional suburbs.
On the other hand, real estate values increased dramatically upon completion of the project, as improvements led to a price jump that doubled real estate values within two to three years, followed by a gradual increase at a higher rate than unimproved areas (12% annually versus 8% respectively). Because of the continuous demand for improved sites that have become a strategic location, private sector investments increased, which led to an increase in tax revenues, which in turn helped support public services and utilities. While additional benefits included mitigation measures to compensate the poorest for their displacement, all residents of the buildings affected by the project, regardless of the legal status of occupancy, were given the right to a relocation grant or compensation option that included subsidized housing [24].

General context
Cairo was established in the 10th century AD as the capital of the Fatimids, in the eleventh century, Salah al-Din al-Ayyubi bounded it and the former capitals of Egypt with a new wall. Later, in the era of Muhammad Ali and his successors, the city expanded outside its walls which were mostly demolished, while historical Cairo continued to express a unique identity that qualified it to inscribe on the World Heritage List in 1979. Al-Darb Al-Ahmar is one of the oldest districts of historical Cairo, which is located south of Al-Gamaleya district and bounded to the east by the Salah al-Din Wall. Although it includes some of the most important Islamic monuments in Cairo, including 65 historical monuments registered by the Supreme Council of Antiquities, in addition to several hundreds of unregistered buildings, it did not receive the same attention as Al-Gamaleya [25]. Maybe that is one of the factors which contributed to transforming it from one of the richest districts of Cairo two centuries ago to one of the poorest. The living conditions within the district have gradually deteriorated, as the average monthly income of its inhabitants of about 100,000 people was estimated to be less than 500 pounds, according to a survey conducted by AKTC in 2005. Because of these conditions, in addition to the forced eviction policies from the vicinity of monuments that the official authorities adopted in the 1970s, the district has lost a large part of its valuable social and economic assets. According to national censuses, the district lost about 50% of its population between the mid-seventies and eighties, moreover, the 1992 earthquake exacerbated that loss [26]. Despite these serious problems, the district remained coherent and the community and family life in it remained strong [27].

The background of urban interventions in Darb al-Ahmar
The Darb Al-Ahmar project is a component of the Al-Azhar Park project funded by the Aga Khan Historic Cities Programme of the Aga Khan Trust for Culture (AKTC), which was proposed to be established in 1984 on an abandoned site in Al-Drassa hills that was used for about 500 years as a city waste dump located between the eastern edge of Historic Cairo (adjacent to the Darb Al-Ahmar) and the tombs of the Mamluks. In that context, about 1.5 km of the Ayyubid city wall was revealed, which led to a new approach by giving a historical character to the AKTC park project [28]. For linking the wall with the historical fabric of the city, the urban and social development of the adjacent Darb al-Ahmar district has been promoted, so that the projects of the park and the preservation of the Ayyubid wall would catalyze the rehabilitation of the poor district. That approach has taken the form of an integrated plan that includes a series of interventions aimed at preserving historic buildings in parallel with large-scale socio/economic development; through several projects that contribute to improving the living conditions in the vicinity of the park [29]. The first phase of the project has funded by AKTC in cooperation with some other parties, while the Social Fund for Development SFD also participated in financing the second phase [26].

Outlines and scopes of urban intervention in al-Darb al-Ahmar
Conserving the fabric and historical monuments was one of the main pillars of the project, but not as a museum, or simply for marketing as a tourist attraction, but on the consideration, that old buildings and traditional social relations are a resource for positive change that embodies the essence of the place. Therefore, the main thrust has been to reintegrate the monuments, old buildings, and traditional open spaces, and to conserve them for their essential characteristics in the daily life of people and re-link them with the multidimensional social and cultural character of the district, to make them as a basis for a realistic and consistent development of Al-Darb Al-Ahmar. Hence, the project included several axes that are: restoration of historical monuments and adaptive reuse of some of them in community services, community development, improvement of facilities and infrastructure, and housing rehabilitation. Based on an extensive study, three zones located on the eastern border of the district and considered the poorest in the district have defined as the intervention zones (Figure 7) so that the individual action plans are linked to the comprehensive program for social and economic development, these zones are [28]: • Burj Al-Zafar Street and its surroundings: located on the northeastern side of the district. The aim was to control the deterioration therein, raise housing standards and introduce new commercial uses. Urban interventions included: construction of two multiple functions buildings like Wikkala, rehabilitation of housing along the southern sector of Burj Al-Zafar Street and Atfet Asaad, rehabilitation of the National Youth Club, improvement of the infrastructure of Burj Al-Zafar Street, protection of the Archeological Triangle, and establishment of a visitor center in it, restoration El-barqya Gate, and the re-use of Burj Al-Mahrouq as an exhibition for the history of the city's fortifications. Also, it has been suggested that vacant land and ruins in the vicinity of Al-Zafar Tower be used for new housing projects and small hotels for locals and tourists, but that never implemented ( Figure 8).
• Aslam mosque zone: located in the central part of the Ayyubid wall, interventions have been carried out aimed at improving housing and infrastructure, and developing community initiatives. Those interventions included: rehabilitation of housing in the northern sector of Darb Shaghlan, development of Aslam Square and the rehabilitation of the surrounding housing, adaptive reuse of the Darb Shaghlan madrasa as a community center and developing its surroundings, restoration of the Aslam al-Selahdar mosque and Bab al-Mahrouq which connects the district to Al-Azhar Park, and developing the vocational training center at Abu Hariba ( Figure 9).
• Bab Al-Wazir zone and its extension along Al-Darb Al-Ahmar Street: located in the southeastern sector of the district. The interventions aimed to improve its infrastructure and activate unused assets, especially the salient features that could be incentives to attract visitors and support the economic devel-

Financing
By late 2004, about 4 million USD had been spent on socio-economic rehabilitation in the district for housing and monument restoration, funded by grants from the Ford Foundation, the Egyptian-Swiss Development Fund, the World Monuments Fund, and the Aga Khan Trust for Culture. Moreover, a larger rehabilitation program was implemented between 2005 and 2008 in which the Social Fund for Development, Ford Foundation, Canadian International Development Agency, and the AKTC participated with contributions that added 800,000 USD to the program, as well as direct financial contributions to residents (share 30% to 50% of rehabilitation costs); And the Aga Khan Agency for Microfinance for supporting various income levels. Thus, the total final budget for the HRP is approximately 3,249,000 USD. On the other hand, the microcredit program achieved a recovery rate of 99% within seven months  of its launch, while the rate of repayment for the rehabilitation of residential buildings reached 99.6% over a period of 5 years [26].

Impact on the local community
At the start of the project, AKTC conducted detailed surveys of the socioeconomic needs of locals, through which a list of priorities emerged that included: training, sanitation, garbage collection, housing rehabilitation, primary health care, community services, and the need for microfinance. Hence, several programs were launched to improve living conditions in the district and conserve its historical character [25].
-Training, employment, and microfinance: The first efforts directed to the district began in parallel with the establishment of the park, the Ayyubid wall rehabilitation, and restoration of some monuments in the district, so many training programs have been implemented on crafts skills, including more than 150 training opportunities in gardening, architectural works, and rediscovered the rare skills such as the Arabesque. A series of activities also have been carried out in other fields with local partnerships to create job opportunities. During the first four and a half years of the project, about 1,300 people were employed. To support the income-generating activities, a microcredit program was established to finance handicrafts and retail trade. The recovery rate reached 99% within seven months, about 53% of these loans went to the retail sector, 35% in domestic industries, 12% to service and transportation companies, the women benefited about 25% of them. Although these loans have been disbursed in greater numbers than expected, their total value was relatively less than expected. That reflected the small size of the local economy and the very low-income levels prevalent in the district [28]. -Infrastructure, community services, and open spaces: the project launched a large-scale development plan aimed to improve and develop the infrastructure in the intervention areas and the open spaces within them, to create active social spaces, create better conditions for private investment, and enhance the multiplier effect in the other poor areas adjacent to the three intervention zones of the project through encouraging similar rehabilitation initiatives funded by the private sector. As well as providing basic social services such as health, education and solid waste disposal in cooperation with the relevant local institutions and strive for enhancing their organizational and institutional capacities.
-Housing rehabilitation: a bottom-up methodology has been adopted to design the housing rehabilitation program HRP so that a series of preparatory studies were conducted that included: a physical survey of buildings, a social survey of residents, a lifestyle assessment, a structural assessment, and a health risk assessment. That is to define general procedures and target sectors for intervention. To activate that program, the al-Darb al-Ah _ mar Community Development Company (DACDC) has been established in partnership between AKTC and the Social Fund for Development at a rate of 50% each, as a company responsible for the HRP as well as social and economic programs, infrastructure improvement, and programs related to open spaces. Through that company, the program has implemented with a five-stage process [25]: (1) Collecting and analyzing applicants' data to verify the eligibility of the applicant and the house to enter the program, (2) Documentation the condition of the buildings and housing units to verify whether could be rehabilitated, (3) Conducting a household social assessment to better understand the inhabitants and their needs, (4) Conducting a financial evaluation of each household in terms of their financial assets and borrowing capabilities, (5) The implementation stage, which starts once a contract is signed between the building's occupants and the rehabilitation implementer (DACDC).
To overcome the hurdle of the lease law, the HRP program followed a participatory approach involving the property owners and the tenants who agreed to contribute to the costs of rehabilitating their units instead of the owner with an appropriate increase in the rent. The HRP provided tenants with a mechanism that enabled them to obtain affordable housing loans designed according to their individual needs. The interest rate ranged between 5% for residential units and 12% for commercial units. During the first phase of the project, the financial contribution of the inhabitants was about 8-10%, later it increased to about 30-50%, while the remaining percentage was funded by the project. The repayment rate reached 99.6% over a period of 5 years, indicating that the beneficiaries didn't stay in long-term debt, this may be partly due to the assessment of applicants' repayment capabilities at the initial investigation stage of the project. The program targeted the rehabilitation of 200 residential buildings (equivalent to 13% of the housing stock in the three intervention zones) by the end of 2009. However, the rate of progress was slower than expected due to the weak financial capabilities of most of the district's inhabitants. During the first phase of the project (2000-2003)19 residential buildings had been rehabilitated (a total of 70 units), and by the end of the second phase (2004-2009), the number of residential buildings that had been rehabilitated reached about 110 buildings (about 400 units), in addition to nearly 50 applications was understudy [30]. This indicates that the poorest groups have not benefited enough from the program.
Associated environmental impacts: The removal of the waste dump that accumulated over 5 centuries in Al-Drassa hills east of al-Darb al-Ahmar had a positive effect on the public health of the neighborhood as a whole. On the other hand, one study indicated that the amount of green space in Cairo was equivalent to the size of one footprint per inhabitant, so the establishment of Al-Azhar Park in this thirty-hectare site was like a lung for the densely populated historic district ( Figure 11) [28]. As urban green spaces in general play, a major role in limiting the impact of Urban Heat Island due to their absorption of direct and diffuse solar radiation, as one of the recent studies confirms that large parks of more than 10 hectares lead to a reduction of about 1-2 °C that extends over a 350 m distance from the park boundary [31] [32]. Figure 11. Al-Azhar Park, next to Al-Darb Al-Ahmar [28].

Project sustainability
After the project has completed, it was suggested that the DACDC be transformed into a local non-governmental organization to ensure the sustainability of the project, but that did not happen due to the lack of financial resources. Besides, after the 2011 Revolution, the situation of the built environment in historic Cairo has changed, due to absence of the state control during this phase that has led to the demolition of a significant number of traditional buildings and the flagrant building violations especially in terms of building heights and architectural styles ( Figure 12). Furthermore, due to the economic downturn in the following years, many tenants have been unable to repay the loans they contracted [34]. Some studies also indicated that the lack of maintenance mechanism for the rehabilitated houses made many of them deteriorate again even before ending the project [35].

Analytical studies, results, and conclusion
Based on the two previous case studies of El-Hafsia and Al-Darb al-Ahmar, this concluding part of the paper will deal with analyzes of the impact of urban interventions in both of them with two approaches, the first: by reference to Valletta Principles, and the second: by comparing the role of heritage-led urban renewal in the integrated treatment of the two historical urban areas. This will be taken as a starting point for extracting the results of the research.

Evaluating the impact of interventions by reference to Valletta Principles
Despite the difference in circumstances and trends between urban interventions in each of the Hafsia and Al-Darb al-Ahmar projects, each of them has brought about, in some way, qualitative changes in the urban context and the historical characteristics of each district. To assess these changes, the effects of these projects have been observed on the natural, social, built-up environment and intangible heritage in both districts by reference to Valletta Principles as following (Figs. 13, 14): (  • Change and the natural environment: The changes have positive effects on the environmental context that have been improved by eliminating abandoned sites and the associated risks they pose to public health ( Figure 15).    Based on the above themes, the positive effect of these interventions is evident in general in both cases, but the most obvious effects of the intervention in El-Hafsia have been focused on the built-up and social environment, while the clearest effects in Al-Darb al-Ahmar have been focused on the natural environment in particular.

A comparative analytical study: the role of heritage-led urban renewal
Based on the previous study of the two cases, a comparative analysis will be made to try to answer the questions previously raised in the context of the theoretical background of this paper that related to the role of heritage-led urban renewal in the integrated treatment of historical urban areas in terms of political, cultural, social, economic, urban, and environmental issues.

Political aspects
In the Hafsia project, the urban intervention has begun as a political response to contain popular pressures that confronted the removal of old neighborhoods, then an institutional framework was founded by establishing the Association for Safeguarding the City (ASM) as the body responsible for guiding plans in the Old City. Because of the global reputation of the first phase, the second phase was initiated in cooperation with the World Bank, which laid the foundation for a national approach to planning low-income housing programs that continued later in projects in other areas such as Al-Wakail and Al-Halafawi projects.
In the case of Al-Darb al-Ahmar, the project was not carried out within the framework of a public policy, as the urban intervention came accidentally in the context of the establishment of Al-Azhar Park and the revealing of the Ayyubid wall adjacent to the district by the Aga Khan Association for Culture, which had partnered with various parties by coordination with the local authorities as a representative of the political authority. In that context, the Al-Darb Al-Ahmar Community Development Company DACDC was established as a competent authority to implement development programs, but it did not continue after the end of the project due to the lack of financial resources and the lack of political support.

Cultural aspects
Although the Hafsia district had reached a state of urban and social deterioration that almost obliterated its identity, the urban intervention that included the entire district was able to restore the historical fabric and simulate the traditional architectural styles of the old city with simplified methods commensurate with the changing circumstances. Such improvements of the urban environment have enabled to retain the indigenous inhabitants and attract new residents who contributed to revitalizing traditional ways of life and enhancing local cultural characteristics as a continuation of the historical fabric of the city. However, despite this, the district did not become a tourist attraction due to its lack of prominent historical landmarks and variety of markets compared to the central area of the old city.
On the other hand, in Al-Darb Al-Ahmar, the urban intervention in the three zones adjacent to the Ayyubid wall and Al-Azhar Park targeted the restoration of some monuments, the development of public spaces associated with them, the rehabilitation of a very limited proportion of housing, as well as the provision of some community services. So the impact of the limited area for intervention was like creating a cultural belt around the new park. However, from a positive point of view, the reuse of some historical buildings and heritage sites in contemporary social and cultural activities has been a noticeable impact on revitalizing these assets and link them to the daily life of the inhabitants. That has relatively enhanced the process of building the identity that necessary to strengthen civil society.

Social aspects
In the second phase of the Hafsia project, the mistakes related to the housing of the poorest classes that have appeared during the first phase corrected. Although the second phase of interventions has doubled the prices of land and real estate, the measures taken reduced the related impact on the poor. The solidarity approach that has been implemented through a crosssubsidize mechanism, made it possible to finance the rehabilitation of housing for the poorest groups to keep most of them in the district. Further, support has been provided to the inhabitants affected by the demolition and new construction, regardless of their legal status, which included allocating a percentage of new housing units with affordable rentals or housing support in other areas. The social aspects also included the provision of a share of job opportunities for the less-skilled groups, and facilitate a system of lending that has been continued after the end of the project and was circulated throughout the city later.
In al-Darb al-Ahmar, community development has been a fundamental component in urban interventions that included the provision of social services and building capacities, as well as training on traditional crafts that contributed to the completion of housing rehabilitation and restoration of historical monuments. On the other hand, interventions in the housing sector have limited to rehabilitating some houses in specific zones of intervention with partial support and flexible loans commensurate with the financial capabilities of the inhabitants. That did not enable the poorest groups to access support, therefore the impact of the interventions on improving the housing environment remained limited. However, the project did not result in the evacuation of residents except for temporary periods during rehabilitation. Although it has been proposed to build new houses and small hotels in the demolished sites, which never happened due to lack of resources and administrative and procedural complications.

Economic aspects
The first phase of the Hafsia project has fully funded by the government, and in the second phase, the World Bank also participated in financing with a loan equivalent to about half of the capital. Then the balance was financed from profits from the sale of new housing, shops, and the sale of lands serviced by utilities to the private sector, which contributed to the financial sustainability of the project. The increase in the demand for the strategically located improved parcels has led to doubling the prices in a short time and attracting private investments to the district, which helped revitalize the economic climate and create new job opportunities in addition to increasing the tax base that supported public services and utilities. However, on the other hand, the district's lack of prominent historical landmarks did not make the tourism activity play a role in supporting the local economy.
In the case of Al-Darb al-Ahmar, the project started without government funding, as the first phase has funded by the Aga Khan Association for Culture with the participation of the Global Monuments Fund and some other international development institutions, while in the next stage the Social Fund for Development, which finances from the state's general budget and international grants, as a government institution participated with The Aga Khan Association in the establishment of the Darb al-Ahmar Community Development Company (DACDC), which did not continue after the end of the project due to the lack of financial resources so that the housing rehabilitation and community development efforts stopped at this point, as well as the condition of many rehabilitated houses deteriorated due to the lack of maintenance later. Although the project was not institutionalized, its economic impact was a catalyst, as the restoration of some historical monuments and the establishment of Al-Azhar Park attracted tourism to the district that was one of the marginal areas in Cairo. It also stimulated the local economy by stimulating small enterprises and traditional handicrafts and providing new job opportunities that led to expanding the tax base.

Urban aspects
In Al-Hafsia project, the essential features that express the identity of the old city were taken into account when constructing the new buildings. Therefore the continuity of the organic pattern of roads, markets, and traditional forms of housing was preserved and adapted to suit changing conditions and economic requirements, whether in terms of design diversity or simplification of architectural vocabulary or allowing multiple floors in specific places and to an extent commensurate with the heritage environment. That has led to the homogeneity of the old city's fabric so that the district is not easily distinguishable from the rest of the old city from an aerial perspective.
In al-Darb al-Ahmar, the urban interventions in specific zones have contributed to enhancing the historical quality of those zones and preserving their identity, despite the separation of zones of intervention which seemed as separate islands within the deteriorating urban context, that has weakened the sense of place and its identity, so that the interconnectedness and complementarity of the historical fabric have remained missing. Besides, the project's failure to include a comprehensive vision for the development of dilapidated sites left the opportunity to build on them later, with patterns and heights not commensurate with the historic environment.

Environmental aspects
Although the Hafsia project did not add green areas to the district, it contributed positively to improving the environmental conditions and eliminating the abandoned sites that were hotbeds of pollution. As well as supplying facilities and infrastructure, which has helped protect public health.
While the largest contribution of urban interventions in Al-Darb al-Ahmar has focused on the vast green areas in Al-Azhar Park, which has been built on the site of the former landfill adjacent to the district. Although the cost of visiting the park for recreation has been exceeding the capabilities of the majority of poor inhabitants, its positive impact on the local climate and the quality of the historical urban landscape has been reflected in the district as a whole. Moreover, improving facilities and infrastructure had a positive impact on public health in the limited intervention zones.

Results and learned lessons
Previous analytical studies of the two cases of El-Hafsia and al-Darb al-Ahmar show perceptible progress in the concept of heritage conservation, which has become combine two main concerns: the maintenance and protection of heritage stocks on the one hand, and development of local communities within the awareness of cultural heritage on the other hand. However, this relatively recent trend of Heritage-led Urban Regeneration is still a rare urban practice in our Egyptian cities in particular and in developing countries in general, as many of our historic districts in cities such as Cairo, Alexandria, Rosetta . . . which have been left for many decades to the uncontrolled development by the private sector, regardless of any other cultural or social values. These conditions have already led to a serious deterioration of many such districts, parallel to the reduction of the middle social classes by displacement or falling below the poverty line, which has also led to the weakening of many of the cultural, social, and ethical values that support the Egyptian identity.
In the context of these critical conditions, the expansion of Heritage-led Urban Regeneration projects has become an urgent necessity despite the serious problems it faces, that may be a large part of which relates to economic considerations, especially the provision of adequate financing, with the weak financial returns it achieves compared to other high-profit real estate projects. On the other hand, the indirect returns that result from revitalizing the local economy, improving environmental and social conditions, and developing human capital should not be overlooked. Therefore, the research ends to extracting the most important lessons learned from these experiences, which can be taken as reference bases that can be relied upon in future urban interventions in historic districts, to achieve the goal of upgrading local communities. That includes: • The importance of planning urban interventions in historic districts within the comprehensive development policies framework. • The significance of political support and the central role of the state in determining intervention strategies that meet the basic needs of local communities. • The importance of implementing mechanisms that help preserve historic districts with their indigenous inhabitants as one of the most significant factors for preserving cultural legacies, the identity, and the spirit of heritage sites that support their continuity and prosperity. • The vitality of the role of restoring and reusing historical monuments, and integrating them into contemporary life to achieve the sustainability of urban heritage and to enhance belonging and identity. • The axial role of the solidarity systems in supporting housing rehabilitation programs for the poorest groups in society. • The importance of training and capacity-building programs in improving the living conditions of local communities. • The need to adopt strategies for mitigating the negative effects of the value increase in the real estate assets in the areas of intervention on the lower-income groups. • The importance of establishing effective partnerships between government sectors, international donors, and civil society institutions to finance urban interventions in historic districts. • The importance of regulating the urban interventions to ensure their consistency with the historical fabric and traditional building patterns for enhancing the integration and continuity of the historic environment. • The importance of having a comprehensive vision for urban interventions that include the rehabilitation of old buildings, the restoration of historical monuments and their reuse in new functions whenever possible, improving the public spaces, as well as the development of the vacant lands and demolished sites within the historical fabric and establish binding restrictions for buildings upon. • The need for attracting the private sector to invest in these districts within binding standards to stimulate the economic climate and contribute to the financial sustainability of projects.

Conclusion
Urban interventions in historical districts face vast challenges related to how to reconcile conserving the historical importance of these districts on the one hand, and preparing their urban environment to meet the changing requirements of local communities on the other. Perhaps a large aspect of the problems facing such interventions is the association of these districts with the livelihood of broad sectors of the lower-income groups in society, whose lives, work, customs, and traditions merge with the heritage environment and contribute in one way or another to defining the identity and spirit of the place. Therefore, keeping these residents with their traditional practices and improving their lives is no less important than the importance of conserving the historical buildings. That poses additional challenges regarding how to empower these groups of the urban poor, and how to support community services and housing programs that meet their basic needs on the one hand and integrate with the historic environment and enhance it on the other. Such challenges also relate to developing institutional frameworks that enable sustainable urban interventions achieving in light of limited financial resources. This paper provided analyzes of two cases of urban intervention practices in historic districts in the Arab region; through them, the most important learned lessons that can be taken as a reference framework of such projects were identified. Finally, the paper affirms that urban interventions in historical districts aimed at developing real estate, human and cultural capital alike have become a vital issue that involves many dilemmas that require further research to reach innovative approaches that support the achieved results and help to overcome the current gaps.

Methodology
The research follows a descriptive and analytical approach. The paper consists of three parts, the first includes a review of related methodological issues, and the second provides a study of urban interventions models in historical districts in the Arab region in order to identify the most important strengths and weaknesses aspects and study the extent of their impact on local communities. Depending on this background, the third part presents analytical studies of these models in order to extract the most important learned lessons that can be taken as bases for upgrading local communities in such historical districts.

Research sources
To address the issues raised for research, secondary research techniques were used, which included a review of international conventions, international and national reports, previous studies, and data available on official websites.

Disclosure of potential conflicts of interest
No potential conflict of interest was reported by the author(s).