The Arrabal Alcázar Viejo from Cordoba: Urban, Hereditary and Sustainable Regeneration of the Historic City Centre

Building sustainably begins with planning. The urban regeneration of our old city centres requires finding a functional balance between residential and touristic areas, especially between them and the rest of the city. In order to build public facilities or housings in a sustainable way aiming at repopulating them, municipal ordinances are needed. They shouldn ́t evoke idyllic images that create an attractive and touristic reality that never existed. Repopulation, tourism and heritable identity have to walk hand in hand thanks to the planning. My thesis focuses on an arrabal (historical suburb of 13th century) called Alcázar viejo in Cordoba, where traditional houses are still in use. Each ancient house (casa patio), which count with a popular courtyard, used to be the home of several families. Nowadays these structures are owned by single families. After being recently declared “Intangible Heritage of Humanity” by UNESCO, the tangible value of them has been raised, resulting in such an increase in tourism that their residential use is becoming endangered. Cordoba ́s current Historic City Centre Special Protection Plan (PEPCH) lays down an ordinance regarding the traditional casa patio for all this area. This rule is breaking arrabal ́s popular identity and makes it difficult to repopulate it. This is a problem for eco-efficient and sustainable constructions. The Plan pretends to impose an historical image not adapted to society ́s demands. So here I expect to propose improvements for a sustainable regeneration of the arrabal, especially regarding the planning, balancing it with tourism and heritage identity.


Introduction
Cities are cultural landscapes between two realities: territorial growths and socioeconomic dynamics.The treatment of different urban scales leads to reorganization problems, especially when we have to improve the relationship between a historic city centre, which contains the city´s heritage identity throughout the centuries, and its outskirts.In the same way, historic city centres are heavily rigid owing to their material and urban structure.Likewise, this character has increased during the last years because of strict and protective regulations, which have frozen the present day urban image of a part of the city.That is an irony, since the historic city centre has always been an historical and changeable city according to the different civilizations that have dwelled in it.This character is essential to a sustainable and eco-efficient historic city centre (a city from its beginnings to the Industrial Revolution).Nowadays there is a breakdown between the new outskirts and the historic city centre, which is less attractive to the contemporary society because of their new necessities, causing negative effects such as excessive outsourcing, depopulation and loss of identity, thematic tourism or obsolescence of the urban and public spaces.
The current historic city centre plannings belongs to the new stream of urban renovation that was carried out in Europe from the 1960s to the beginning of the 21st century.This new urban trend was in favour of revaluating and recovering the inherited city.In other words: monuments (defined as elements with great singular relevance) and architectural ensembles, whose value is collective.In this way, the Modern Movement, whose supporters´ ideas of a "new city" imposed on the existing city without any sensitivity, finished.In its place, a new stream appeared whose goal was the protection and conservation of urban heritage.Thanks to that trend, most of the ancient city centres of old European capitals have been preserved.
Nowadays, forty years after, we can assure that this perspective in urban regulations has been consolidated.However, in many cases the regulation is extremely protectionist and prevents the renovation of buildings formally and functionally.Because of that, several urban scientists think that this is the cause of our serious contemporary problems like material urban deterioration, obsolescence, thematic tourism and depopulation of old city centres.So like this, it is agreed that the solution should be presented from a point of view in accordance with the morphological and functional renovation and requalification regarding the different zones of the historic city centre and their connection with the outskirts.We might ask ourselves: Is this a new urban wave?To Falini [1] the idea of a united and homogenous historic city centre is in crisis, while sustainable regeneration allows us to recover the residential heritage, in other words, to keep the old city alive.
Nowadays, a new urban and heritage cycle is beginning in Europe: urban scientists believe that regeneration is the key to finding an equilibrium between two focuses: societyterritory versus tourism-heritage.Likewise, it is fundamental to obtain a real and sustainable integration between the historic city centre and the outskirts.Our challenge consists of finding the resources to protect and rebuild the relationship among the local population, whose social and economic demands are changeable, and their territory.To Busquets [2] urban planning in the twenty-first century must guarantee that historic city centres keep being alive.Cordoba is considered one of the biggest cities of the Middle Ages, after Rome and Constantinople (to which its Christian conquerors related it after the heroic deeds of the siege of Cordoba).However, the city began to decline after the Christian conquest, given that it was the first time that Cordoba had not been a headquarters of a state or national government.Progressively, Cordoba became an ordinary city of the Christian Kingdom of Castile.As a consequence, the historical suburbs or arrabales (in other words, neighbourhoods outside the historic wall) were destroyed, except from the Roman walled city.Of course, this city was inside the Walls and would have been called Medina by the Arabs and Villa by the Christians.Another Moorish walled arrabal (called Axerquía), placed in the East of the Medina, survived too.One of the Christians´ first decisions was to fortify the southwest side of the city, expanding the Muslim alcázar (old Arab castle) and creating the last historical arrabal inside it.They designed a Christian and urban setting, that today it still exists and we know as the Alcázar viejo neighborhood.

The Historic City Centre of Cordoba
After the beginning of the last century there were settlements outside Cordoba´s walls that were consolidated throughout the following years.However, it caused the disconnection between all the outskirts and the historic city centre.Because of this, general plans, approved by local governments after the Spanish Civil War, tried to link the different parts of the city in order to transform Cordoba into a compact town.However, nowadays there are still unconnected urban areas that constitute an opportunity to work on.
The historic city centre of Cordoba contains its population´s heritage identity.Inside it, the most important civilian or religious monuments and the most popular and traditional houses can be found.Because of that we can affirm that the main character of the historic city centre is its heterogeneity.However, Cordoba´s main value keeps on being the conservation of its ancient use as a residential area (for 50.000 inhabitants, 15% of the actual total population).However, as can be seen in figure 1, currently the population has been moving from the centre to the outskirts since the end of the last century.Not surprisingly, Castilla del Pino [3] recommends: hurry up if you want to see Cordoba.

Cordoba´s Historic City Centre Special Protection Plan (PEPCH-2003)
On the 8th of May, 2003, the government approved definitively Cordoba´s Historic City Centre Special Protection Plan (PEPCH in Spanish).Its author Daroca Bruño [4] recognizes the difficulties in reaching PGOU-1986´s objectives (the previous plan), which consisted of matching up "downtown" with the historic city centre.However, he tries to avoid the depopulation of the historic city centre.In this way, he aims to reinforce its central position, its historic past, its general public facilities and its ring-shaped accessibility.The ring-shaped city centre´s main quality is balancing the relationship between the historic city centre and the outskirts.
As its name points out, PEPCH is a more protective than reforming instrument, since it "lays down three different building ordinances from maximum to least protection, according to their possibility of being renovated: a) Monuments, buildings and architectural ensembles; b) Zone of protective building typology and c) Renovated Zone".Subsequently, the entire traditional old town is under a strong urban discipline.
The ordinance of typological protection of buildings affects the whole of the historic city centre except for the already renovated zone (North Villa).Effects of imbalance and a possible depopulation can be seen because a single ordinance imposes the same rules to preserve the same patio in a very heterogeneous ancient city.Therefore, it turns out that an ideal and historical building typology does not allow the construction of housing according to new generations´ necessities.Apart from rules about maximum building height, projections, façade composition and building covers, the main and characteristic element of the ordinance of protective building typology is the heritage courtyard or patio and the adjacent gallery.In this way, all the building must be organized around that singular element that aims to evoke the traditional patio of Cordoba.Daroca Bruño [5] thinks that is dangerous to restrict the historic city centre because of an overly strict general interpretation of Urban Management of Cordoba, which does not study each particular case.

The arrabal of Alcázar viejo
The arrabal of Alcázar viejo was a new and Christian historical suburb that was knocked into shape after the reconquest of Qurtuba.In the late Middle Ages, the Christians´new ideas about urban hygiene and health standards were embraced thanks to a planned urban setting, which was more regular than the tortuous and narrow streets of the Muslim Medina.
Despite its youth compared to the rest of the city, the arrabal played a very relevant role, historically recognized.As an example, in an ancient civil war that took place in 1367, Solano Márquez [6] affirms that King Peter I of Castile, called the Cruel, left Cordoba after a great defeat because he could not penetrate the city because of the brave women that defended the Alcázar viejo while men were fighting in the Campo de la Verdad (nowadays, a neighbourhood in the outskirts next to the Roman Bridge Gate).
There were few important reforms in the arrabal in the Modern Age, except for the establishment of residential use after losing its military character.However, the Christian Monarchs' Alcazar was a military dungeon until the post Spanish civil war period.Nevertheless, the Christian urban setting was consolidated distancing itself from the traditional Muslim typology.To illustrate this, Nieto Cumplido & Luca de Tena [7] explain that originally there were three main streets and a little square in the centre of the arrabal, where the Church of the Ancient Convent of Basilios was located, even though the religious city centre kept on being the Cathedral-Mosque.

The Rural Housing of the 19th Century
Throughout the transformation of Northern Cordoba (the present historic city centre) into a modern and industrial city, the working and popular classes, who belonged to the rural world, remained to the south and the east of the city.In this way, the arrabal of Alcázar viejo was rebuilt without planning, causing the buildings to be lined up along the street, a single storey, with an only bay and a rear courtyard that in fact was the rest of the plot.They were like the three kinds of late medieval houses described by Pino García [8]: tenement housing, gated housing and palace-housing.

The Rural Housing of the 20th Century
During this past development period, Alcázar viejo was overfilled by housing and evolved: houses grew from one to two floors.Façades were renovated in a healthier manner, with a better proportion of openings (windows and doors).Inside the houses, owners constructed a new bay which was joined to neighbours´ party walls.In this way, the rear courtyard was reduced and became a central element with a more functional character in relation to the rest of the house.These transformations follow Sierra´s thesis [9]: a poor, regional and timeless architecture, objectifying an urban space very similar to others that can be found in Andalusia.
However, the people living in these buildings still belonged to the working class, who transformed singlefamily homes into multifamily dwellings.In fact, they were like little familisterios without planning, where 10 or 15 families lived in single rooms of 20-30m 2 and shared common services around the central courtyard or patio: kitchens, laundries, bathrooms, even a water supply from an Andalusian well.
It was at this moment that the Patios Festival was developed.Nowadays, specifically since December 2012, Patios have been declared World Immaterial Heritage by UNESCO.Solano Márquez [10] affirmed in his announcement of Cordoba´s Patios Festival 2013 that the beginnings of this traditional contest could have been the neighbours´ disputes over having the most flowery or welldecorated patio.Little by little, the upper and middle class began to have a good impression of this popular competition because of its traditional and folkloric atmosphere.Likewise, this also applied to rejas (bars) and balcones (balconies).

The Urban Boom of the Last Years of the 20th Century
In the seventies and eighties, the arrabal grew one floor more, from two to three storey buildings, thanks to local urban rules.Furthermore, the lack of protection for the private patio-housing favored that new properties were built in those years.In this way, the old arrabal´s residents did not need to emigrate to the outskirts, because the number of houses increased inside Alcázar viejo.Nevertheless, arrabal´s population decreased by approximately two thirds, since the old patio-housing was too crowded and there were not enough single family homes.In addition, residents´ purchasing power increased and they could afford better housing, even though they had to move outside arrabal.
For this reason, lots of patio-houses were demolished.However, something of them remains preserved thanks to some families, whose generations have always been there, and to popular initiatives that have succeeded in saving them.This is the case of Patio-House number 50 of San Basilio Street, which was kept thanks to the intervention of the Friends of Los Patios Association.
In 1994 UNESCO declared the southern part of the Villa zone and the arrabal of Alcázar viejo as World Heritage Sites, which allowed the decrease of the voracious property development.However, the present protective urban tools were not realized until the beginning of the 21st century.

The Imposition of an Idyllic Model in the 21st Century
The hard urban protectionism that has been applied in the old arrabal comes from Cordoba´s Historic City Centre Special Protection Plan, approved definitively the 8th of May, 2003.This current ordinance is not considered appropriate to renovate housing -taking into account the dimensions, forms and areas of the arrabal´s characteristic plot-.Moreover, the imposed typology does not correspond with Alcázar viejo´s traditional one.Consequently PEPCH neither helps to resolve the problem of depopulation nor to maintain the essence of the ancient arrabal in the new constructions.In the long term, this will lead to a lack of constructive, environmental, and efficient sustainability.
The big central courtyard with adjacent gallery is more appropriate for a knight´s ancestral home than a popular neighborhood community´s Cordoban patio-housing.Therefore, the model that the PEPCH imposes on the old arrabal does not seem the most suited to its identity.
To Barrionuevo [11] it is a very interesting detail to study the evolution of the patio as a principle of the growth and construction of the city.
The arrabal, today Alcázar viejo neighborhood, is still an urban area with human life and activity.It is not a dead museum or historical theme park.Its wealth lies in the fusion of urban sciences and sociology, in this way its total depopulation would cause its decline.

Analysis
Once all the information about planimetric representation was complied, a sample of 36 houses from arrabal of Alcazar viejo was chosen to test the ordinance of protective building typology.This information was provided by the Municipal Historical Archive of Cordoba, the Official Professional Association of Architects of Cordoba, the offices of the Junta de Andalucía and the projects of fellow architects.As shown in the figure 7: houses that are still conserved can be seen in red and partially preserved buildings or buildings with sufficient planimetrical surveying in orange.
Regarding the ordinance of typological protection, it has been established that for single family dwellings the minimum dimensions of the patio must be 5 x 5 metres, while those of multifamily dwellings must be 7 x 7 metres.When this filter was applied during the research period, the following results were obtained:  In single family homes, 14 of 36 patios fulfill the minimum sizes requirements (5 x 5 metres), practically forty per cent of the sample; while, in multifamily dwellings, only four of 36 patios fulfill the minimum sizes requirements (7 x 7 metres), about ten per cent of the sample.
In this case, the ordinance of typological protection does not define a typology that can be matched with the traditional housing of the Alcázar viejo´s arrabal.Therefore, its implementation on small plots favours low density building, which is not the optimal choice in a situation of depopulation.

Conclusions
The regeneration of the historic city centre´s population is an objective of Cordoba´s PEPCH.However, this has still to be met, in fact, the historical district is emptying from the centre to the historical walls, as can be seen in figure 1 on page three (municipal population census´s files of 2011, eight years after the approval of the Special Plan; nowadays the same census reveals a decrease of total population).It should therefore be borne in mind that an excess of building protectionism and rigid construction rules directly affect people´s lives and the sustainable renovation of the historic city centre.
It is true that, at the end of the 20th century there were abuses against the heritage and the new typologies were implemented with little conformity to the city´s past.However, there also were generations of families who, as their level of income increased, renovated their homes according to their hygiene, light, technology and energy needs.As it can be seen in figures 3 and 4, housing grew one floor and the proportion of doors and windows was improved.It is told the tourists that lots of arrabal of Alcázar viejo´s houses are 200-300 years old, but in fact the majority of them are not centenaries.If the arrabal´s housing sustainably evolved during the first two thirds of the 20 th century, why is the urban planning of 21 st century freezing an inherited and idealized image even though the houses have little special value?
This research does not expect to override the current ordinance to implement a new one, but to establish an action programme to renovate sustainably the residential houses from the planning stage and without losing environmental values and heritage.The first point to consider is: the historic city centre is a heterogeneous ensemble set alive.This building diversity implies that the population was also a heterogeneous set but with a strong territorial identity.However, everything must keep an equilibrium with the other kinds of uses that can be developed in the historic city centre, especially domestic trade, tertiary use, education and tourism.To Ximeno [12] the functional and aesthetic homogenization promotes people´s decoupling with the territory.
Nowadays, private promoters are buying houses in the historic city centre in order to convert them into touristic flats organized around an idyllic patio.While the historic city centre´s population is decreasing, the number of temporary inhabitants or tourists increases even though a point of equilibrium has yet to be achieved.To Cervellati [13] if the present cannot be built without a project that is respectful to history and work, to the environment and to art; then the future cannot either.If he calls the outskirts of present-day cities "Chalépolis", Cordoba´s historic city centre could be called "Patiópolis" in the near future.Urban planning has not only to protect historical buildings, but the people living inside them.The true identity, the maintenance and the sustainable building renovation must originate from them.
Below is a summary of the different action criteria to be taken on board: 1-Identify valuable elements of pre-existing buildings to respond to particular situations as they arise on a case by case basis.These may be simple or compound elements: patio, partial gallery, well, zaguán or hallway, staircase area, a third floor, bell gable, Andalusian flat roof, archaeological test pits… And the tools to use: archaeological projects, study of detail and preliminary architectural design to analyse existing housing.
2-Establish urban parameters to keep up the identity of traditional and popular homes in proportion with the arrabal of Alcázar viejo´s plots.Here are some of them: abolish the imposition of a square patio in favour of other irregular courtyards, either rectangular or L-shaped patios or any other organic type without curves; patio measurements must not be imposed except a minimum side of three metres (because of the Spanish technical building code); the patio´s area must be 10-15% of the total plot; the gallery should not be imposed on the whole of the perimeter nor both floors, but a free design without counting its area such as development potential neither the patio´s area (to promote this model); the sequence street-zaguán-patio must be preserved as much as possible; swap hermetic and massive façades for more flexible ones to install doors and windows, whose proportions between emptiness and fullness are 40-60%, to make homes inhabitable (light, natural ventilation, energy); and the possibility of a recessed attic surface above the second storey, such as a third floor or other popular elements like towers or staircases in line with the façade, gables, bell gables or parapet walls (some of them are currently protected by PEPCH thanks to the ordinance "buildings and architectural ensembles").
3-Flexibility in the uses and typologies in line with the arrabal that promote the regeneration of the population level and the equilibrium between residential use and tourism.It consists of juggling single family homes and bi-family or trifamily housing.For example, in crossing parcels (a plot between two parallel streets) it would be two duplex houses linked by a common patio; while, in the case of parcels which are accessible by single street, it would be the same system with a common zagúan or a two storey building with a common patio and an apartment on each floor.Without losing arrabal´s current pedestrian area, the use of the garage must be favoured on ground and basement floors.In this line, it would be necessary to allow to open doors that can be used by cars to enter (without breaking the suggested proportions between emptiness and fullness, of course, and if the archaeological cautiousness allows digging under the patio to build a basement floor).Nowadays, PEPCH bans digging under the main patio, whose central position in relation to the arrabal´s small parcels makes building basement floors unviable.Permit the commercial use by small family businesses on the ground floor, provided that the small business owner or the workers reside on first floor.In this case, the ordinances have to be accommodating to opening two independent access doors, which were usual and allowed during the first half of the 20 th century.
4-Allow the executions of real constructive systems and building materials that improve energy efficiency, the use of renewable energies and the facilities of the houses (water, electricity, sanitation networks, telephony, internet, WiFi, air conditioning) without losing arrabal´s traditional image.These are solutions that allow: façades with thermal insulation to eliminate thermal bridges; carpentry that provides natural ventilation; freedom to design building covers, including the possible combinations of flat (Andalusian kind with energy-improvement measures) and Arabic curved aged-ceramic roof tiles (the latter is the only system allowed at the moment); the incorporation of solar panels or other types of elements for the production of renewable energies that are integrated into the local cultural and natural environments.

Figure 1 .
Figure 1.Depopulation of the historic city centre.

Figure 2 .
Figure 2. Impact of Cordoba´s HCC Protection Special Plan on Alcazar viejo.

Figure 4 .
Figure 4. Housing´s transformation at the beginning of the 20th century.

Figure 5 .
Figure 5.A real estate promotion in the elderly 20th century.

Figure 6 .
Figure 6.Real implementation of the ordinance of protective building typology.

Figure 8 .
Figure 8. Patios that pass the filter in the case of single family homes (left) and in the case of multifamily housings (right).

Figure 9 .
Figure 9. Present patio-housing of arrabal of the beginnings of the 20th century.