Reintegration of Urban Lacunae and Adaptive Reuse in Historic Centers

REINTEGRATION OF URBAN LACUNAE AND
ADAPTIVE REUSE IN HISTORIC CENTERS

Gap reintegration in restoration

The reintegration of voids is closely linked to the field of restoration. A void is the absence of materiality in a painting, sculpture or building. It can affect not only the material preservation of the object and its structural stability, but in particular our understanding of its essence. Gap reinstatement is one of the main themes in the field of ^restoration1. Although it originated in the restoration of works of art, the procedure can also be applied to ^{architectural} restoration2.
The scale of gaps depends on the scale of the restoration operations. When the restoration concerns painting, the architectural surfaces and the void are limited in size and scope. In architectural restoration, the void may be on a larger scale, thus affecting structural parts of the building, such as walls or timber framing. Furthermore, if we broaden the scope of the restoration concept to the urban or landscape scale, the gap increases in volume and complexity. It would be interesting to question whether the architect's reasoning should change as the scale of the void, and thus the scale of the ^intervention, changes3. In the following, we will present a case of the reintegration of an urban void in the context of an adjacent building that was simultaneously the subject of adaptive reuse within the same project.

Reintegration of urban voids

In architectural conservation operations, large-scale voids to be reintegrated can be considered as urban voids. One of the current problems in Spanish historic centers is the existence of urban voids resulting from the demolition of historic buildings. Their existence calls for careful thought to be given to the nature of the construction that is to 'fill in' the awkward voids. Their reintegration can be approached from several perspectives that can be reduced to three attitudes: autonomy, mimicry or ^{reintegration4}.
A total and intentional autonomy from the historical context will isolate the new building, while at the same time creating a discordant element. Mimetism, so widespread in Spain through the identical reproduction of cornices and ornamentation or the preservation of historic façades and the complete demolition of the buildings behind them, betrays the spirit of the times and hinders the future development of the building. Integration offers a wide range of options focused on conceptual, typological and formal reprocessing of the built context around the urban void. Any project that employs one or a combination of these strategies offers a greater guarantee of integration into the urban setting. The starting point of this conceptual reprocessing is to analyze the compatibility between past and present lifestyles and habitats. The typological reprocessing reinterprets the structure of the historical grouping and distribution of traditional dwellings in order to update them in a contemporary key. Formal reprocessing evaluates the abstract linguistic and artistic structure of facades and volumes in order to transform it into contemporary ^{architecture5}. All compositional criteria such as color, geometry, form, shape, volume, texture, material or light are tools with a role in the development of this type of reprocessing. The common objective of the strategies is to preserve the character of the historic center through contemporary architecture. In the following, this approach will be illustrated by describing a project carried out by the authors of the article in the most degraded area of the historic center of Valencia.

Recaredo Building

The project aims to heal a wound in the urban landscape caused by the demolition of a series of historic buildings during the widening of Recaredo street in the traditional Els Velluters neighborhood, located in the historic center of Valencia. It considered the design of two buildings for even and odd numbers (i.e. buildings A and B, with a shared underground parking lot) and the restoration and adaptive reuse of an existing building (building C) with an exit to³³⁶ Maldonado Street.

Reintegration of lacunae in the field of restoration

The reintegration of lacunae is deeply linked to the field of restoration. The lacuna is an absence in the materiality of an artwork, whether a painting, a sculpture or a building. It may affect not only the material conservation of the object and its structural stability, but above all the understanding of its meaning. The reintegration of lacunae is one of the main topics in ^restoration1. It is born in the field of pictorial restoration, but it can also be applied to architectural ^restoration2.
In pictorial restoration, it means the restoration of architectural surfaces and the lacuna assumes a limited scale in size and width. If we further enlarge the concept of restoration to an urban or landscape scale, the lacuna still grows in dimension and complexity. It might be interesting to ask ourselves if the reasoning of the architect should change whilst modifying the scale of the lacuna and, therefore, the scale of the ^{intervention3}. We are going to present a case of reintegration of an urban lacuna inspired in the context of an adjacent building that was simultaneously object of an adaptive reuse within the same project.

Reintegration of urban lacunae

The big scale lacunae to be reintegrated could be considered as urban lacunae in the frame of architectural conservation. One of the problems still present in Spanish historic centers is the existence of urban voids from the demolition of historic buildings. These voids require a reflection on the character of the building to be erected in order to fill these uncomfortable urban lacunae. The reintegration of these urban lacunae can be tackled from different approaches that could be resumed in three attitudes: autonomy, mimicry or ^{reintegration4}. A complete and designed autonomy from the historic context isolates the new building and creates at the same time a discordant element in the context. Mimicry, so diffused in Spain with the imitation of cornices and decorative elements or the conservation of the historic façade demolishing the entire building behind it, betrays the spirit of the time and hinders the future evolution of architecture. Integration offers a wide range of possibilities which mainly contemplate conceptual, typological and formal reprocessing of the context built around the urban void. Any project resorting to one or several of these strategies combined offers greater guarantees for integration in the urban layout. The starting point for this conceptual reprocessing is consideration of the compatibility of ways of life and past and present habitats. Typological reprocessing reinterprets the structure of historic grouping and distribution of traditional dwellings for their contemporary re-proposal. Formal reprocessing tests an abstract linguistic and expressive structure of the facade and volumes to transform it into contemporary ^{architecture5} Composition parameters such as color, geometry, shape, volume, texture, material or lighting are all tools to be developed for this reprocessing. The common objective of these different strategies is the conservation of the character of the historic center through contemporaneous architecture. We are going to show one example of this approach through a project built by us in the most decayed area of the historic center of Valencia.

Recaredo building

This project aims to heal a wound in the urban landscape caused by the demolition of several historic buildings, in part due to the work of widening calle Recaredo in the traditional neighborhood of Els Velluters in the historic center of Valencia. The project focused on the design of two buildings for even and odd numbers (buildings A and B respectively with a shared underground car park in this street) and on the restoration and adaptive reuse of an existing building (building C) which gives out onto calle Maldonado^336.

The action area comprises several buildings dating from the 1960s-1970s and later, indifferent to their historical context, which has created major distortions in the architectural interpretation of the historic center.
Buildings A and B, recently constructed and small in size in relation to their facade perimeters of 33 and 50 meters, these buildings are slightly noticeable and have a major visual impact on the surroundings.
The 6 meter wide façade of Building C towards Maldonado Street, resulting from the realignment of the façades to the street at the end of the 19th century, actually conceals a large 16th century house, extended in the 18th century. Initially, a preliminary study was carried out on Building C, which consisted of research in the Municipal Historical Archives, a detailed survey of the existing building, and a study of the chronotypology of some of the walls and floor plans and other characteristic features. Auxiliary studies included carbon 14 dating of the main beams, sampling of the original decorative elements, stratigraphic analysis of the walls, structural analysis of the buildings, etc.
The design of the recent construction works in Buildings A and B was largely conditioned by the study of the active development and evolution of the pre-existing building destined for restoration (Building C) and the organic development of the extensions and terraces located in the stepped backyard; thus, the gradual configuration of the open space specific to the urban fabric of the historic center of Valencia was achieved on a narrow lot that hardly allows for two openings per ^floor7.
Building A, with a width of 10 meters and a frontage to the rear courtyard, contains housing units with spacious terraces carved into the building volume. Building B, with a width of 7 meters, oriented poorly to the west and lacking a façade to the rear, was designed with a sloping interior courtyard with stepped terraces. This interior landscape of sunken spaces in the main volume allows sunlight to penetrate all levels of the building, including the ground floor, all year round, while providing natural ventilation.
The internal stepped courtyard (optional according to the regulation) provides permanent cross ventilation from the direction of the external façade (with windows as required by the regulation) towards the interior of the building - an absolutely necessary feature given the excessive heat caused by the west-facing orientation. The courtyard configuration also creates longitudinal cross-ventilation between the different exterior courtyards of the building, providing, in succession, ventilation to the residential units and the stairwell.

The area of action features several buildings dating back to the 1960s and 1970s and even later, which were designed independently from their historic setting and have created major distortions with respect to the architectural interpretation of the historic center. Buildings A and B, of new construction and small compared with their respective façade perimeters of 33 and 50 m, stand out and have a major visual impact on their surroundings. The 6 m wide façade of building C onto calle Maldonado, resulting from the late 19th-century realignment of façades on the street, in fact hides a large 16th-century house extended in the 18th century.
Firstly, a detailed preliminary study was carried out on building C, consisting of research in the Municipal Historical Archives, the detailed survey of the existing building and the study of the chrono-typology of the different walls, floors and ceilings, as well as other characteristic features. Additional studies included a Carbon 14 analysis of the main beams, sample tests on original decorative features, stratigraphic analysis of the walls, structural analyses of the constructions etc.
The study of the formation and the constructive evolution of the pre-existing construction to be restored (building C), with an organic growth of extensions and staggered terraces in the back courtyard in the progressive building up of available space frequently found in the historic city center of Valencia, on a narrow plot which barely allows for the presence of two openings per floor, has mainly conditioned the design of the recent construction in buildings A and^B7.
Building A, 10 m deep with a façade to a back courtyard, has housing units with spacious terraces dug out from the building's volume. Building B, 7 m deep with poor orientation to the west and no back façade, was designed with a sloping interior courtyard creating staggered terraces. This interior landscape of spaces dug out from the main volume lets sun in to the entire building down to the ground floor during most of the year, as well as generating natural ventilation.
This staggered indoor courtyard, not strictly necessary according to regulations, provides continuous cross-ventilation from the external façade, which includes windows stipulated by regulations, to the inside of the building. This is absolutely necessary given the excessive heat due to orientation to the west. It also generates longitudinal cross-ventilation between the different open courtyards in the building, in turn ventilating residential units and stairwells.

The sloping courtyard with stepped terraces was designed based on a sun map made specifically for building B to provide the best use of sunlight in the morning. Thus, sunlight is present throughout the building and on the successive terraces on the different floors, even at ground level, in all seasons, welcoming the public entering the building or waiting for the elevator. A wooden pergola supporting a glass plate acts as an optical filter and provides the necessary privacy to separate the public function of the ground floor from the private function of the upper stepped floors.
The cross-section of Building A and especially of Building B resembles a huge piece of avaivaiþer, with courtyards, terraces and green spaces carved into the building's volume. Thanks to the correct orientation, these spaces provide exceptional natural daylighting inside the building and allow for strategic cross-ventilation to counteract the excessive heat caused by the sun's rays penetrating the south and west-facing rooms. However, in both buildings (A and B), the permanent facade cladding, designed 40 centimeters thick to shelter the sliding awnings from the interior, dominates the terraces, perforating the spaces based on building codes in keeping with the historically small width of the neighborhood's parcels to avoid an overly uniform and homogeneous horizontal interpretation that would alter the scale of the building in relation to the urban landscape. In keeping with local building tradition, the blinds have movable slats in all sections and allow for a subtle and expressive adjustment of the strong Mediterranean daylight. Like the leaves of an onion, the facade can be divided into separate layers with sloping communicating windows, sliding blinds whose variations in texture depend on the angle of the slat and the use of lime mortar plaster for the exterior facade, which creates interesting architectural variations on the building envelope.
Most of the residential units have been designed as integrated duplexes with upper and lower floors well integrated into the building massing, making clever use of the terraces. As for the new buildings A and B, the careful elaboration of the canopy of facade A, the sloping courtyard based on the south orientation of the sunlight, the incorporation of the stacked duplex living units, and the dynamic structure of the openings on both facades dictated the distribution of the different floor plans from one level to the other and led to a careful execution of the design in terms of detailing, electrical, gas and heating installations; particular attention was paid to the supply of drinking water, sanitation and the compulsory ventilation system in kitchens and bathrooms. Although different, all the living units each have a characteristic terrace measuring more than 20^m2, in keeping with a tradition in the historic center of Valencia that dates back to at least the 16th century.

The sloping courtyard with staggered terraces was planned following a solar chart designed specifically for building B in order to ensure the best possible use of morning sunlight. Not only does the sun stream through the building and over the successive terraces of the different floors, but it also reaches the ground floor in the morning for most of the year, lighting up people entering the building or waiting for the elevator. A wood pergola supporting a sheet of glass acts as a visual filter and provides the privacy needed to separate the ground floor for public use from the staggered upper floors for private use.
The cross-section of building A and especially that of building B resemble a large Gruyère cheese with courtyards, terraces and garden spaces dug out from the building's volume. With the correct orientation these spaces provide exceptional sunlight inside the building and allow strategic cross-ventilation which counters the excessive heat caused by the sun inciding on rooms in the south and west facing façades. Nevertheless, in both buildings A and B, the continuous skin of the façade deliberately built 40 cm thick to accommodate the sliding shutters inside, towers over these terraces, perforating spaces following composition guidelines suited to the historic narrowness of the plots in the neighborhood to avoid an excessively uniform and homogeneous horizontal interpretation which would alter the scale of the building in the urban landscape. Following local building tradition, the louvered shutters have moveable slats in all their sections and allow a nuanced and suggestive regulation of the strong Mediterranean daylight in the city. Like an onion skin the façade can be divided into independent strata with tilt and openable windows, sliding louvered shutters whose textural variations depend on slat angle, and the lime mortar render of the outer façade which provide the building envelope with interesting architectural variations.
Most of the housing units were designed as interlocking duplexes with staggered upper and lower floors, which fitted better into the building as a whole while respecting and improving the respective terraces. As regards the buildings of new construction A and B, the carefully thought out crowning on façade A, the sloping courtyard following the south orientation of sunlight, and the incorporation of overlapping duplex housing units, as well as the changing composition of the openings on both façades have dictated a distribution of floor plans which change from one level to another and have prompted a painstaking execution of the project in all its details and electric, gas and heating installations, but above all the supply of drinking water, drainage and forced ventilation shafts in kitchens and bathrooms. Even though they are different, all the housing units have a characteristic terrace surface of over 20^m2, a tradition in the historic center of Valencia dating back to at least the 16th century.

The permeable floor of the terraces is at the same level as the interior floors of the apartments. In fact, the terrace communicates in a surprising and unexpected way with the apartment at the level of the interior floor plan. Waterproofing and drainage have been solved by arranging the floor in steps and camouflaging it into the living units on the lower floors. In Building B, the stepped levels were also used to house the suspended beams covering the single 7-meter veranda, as a double veranda would have marked the distribution of the apartments with intermediate posts.
The crowning of the new buildings A and B was solved with an inverted cornice consisting of a U-shaped stone channel at the top of the wall, visibly shaded and functioning as a permanent gutter, preventing rainwater from splashing or running down the façade. The shadow created by the inverted cornice is not exactly in keeping with the construction tradition of this historic building, but its abstract quality is perfect for the pronounced shadow marking of the building's canopy.
However, the restored Building C, originally slated for demolition, has been the subject of research. Therefore, the linear structure dating from 1580, the 18th century outbuildings characterized by a sgraffito relief unknown at the time of the survey, the carpentry from 1864, the floor and facade from 1901 were restored. The owners of the building were allowed to gain space by extending the original façade to the street for realignment reasons. In fact, the building housed an interesting collection of floors and roofs of historic value, the earliest dating from 1580, with later additions made around 1750, 1864 and 1914. The 1750 floors and ceilings exhibited period decoration, which contributed to the dating, and these have been restored despite poor condition. The terrace roof dating from 1750 was quickly converted to a storey with the construction of the rear of the building in 1914.
Incidentally, the historic building proposed for restoration has been transformed into a kind of museum of the evolution of housing in the historic center of Valencia, documenting the many interesting stages of construction, consolidation and transformation. The project to restore the three residential buildings set out to reflect their past without compromising any of the construction phases. In accordance with the theory of organic growth present throughout the history of the buildings, the aim of this intervention is to constitute a new stage of life to be studied and recognized as such by future generations. The generosity of the resulting spaces and the hospitality of the recovered historic building have generated three exceptional examples of subsidized residential housing dating back to the 16th century, a rather rare situation that should be much more widespread.
The whole project has resulted in 23 subsidized housing units in the form of a series of 90^m2 residential units benefiting from the maximum floor area for use laid down in the current Spanish regulations. 20 housing units are in new construction (buildings A and B) and the other 3 are restored (building C). In addition, the two-level underground parking garage in the basement of buildings A and B, the courtyard of building B and the street between the two buildings provide 42 parking and storage spaces; 23 belong to subsidized housing units and the rest are available to the residents of the neighborhood, affected by the scarcity of parking spaces. The two-storey parking garage below the shallow water level in this coastal town was a real engineering feat. The floors below street level contributed 3,000 kg/m2 of static load, and the dynamic load was also analyzed to allow traffic to flow smoothly. The total cost of the underground engineering works was therefore high, but this was balanced by the lower cost of about €1,^000/m2 of restoration and new construction works.
Commercial spaces on the ground floor of the buildings have been leased to local associations, among others. The housing units, municipal properties currently rented to low-income people, are proving their effectiveness in terms of daylighting and cross ventilation. This makes it possible to avoid the use of air conditioning and heating systems for most of the year, as well as to showcase the vast exterior surfaces as a succession of terraces and permeable floors, and the ability of the architecture - particularly in the case of building B - to provoke and generate social relations for inter-community collaboration.

The filtering paving of the terraces is all at the same level as the indoor flooring of housing units. In fact, the terraces make their presence felt in the housing surprisingly and unexpectedly by continuing the horizontal plane of the interior paving. Waterproofing and drainage are resolved by staggering the floor structure in a way that is not noticeable in lower housing units. In the case of building B, these staggered levels have been used simultaneously to accommodate the hanging beams which cover a single porch 7 m long, given that the construction of a double structure porch would have dotted the distribution of the housing units with useless intermediate pillars.
The crowning of new construction buildings A and B was resolved with a kind of inverted cornice consisting of a U-shaped stone channel at the top of the wall, creating its own clearly visible shade and acting as a continuous gutter which avoids rain splashing or running down from the top of the façade. The shade created by this inverted cornice is not a literal reproduction of the construction tradition of this historic building, but its abstract quality is perfectly in keeping thanks to the shadow echoing the upper crowning of the building.
However, restored building C, originally due for demolition, was studied and its linear structure dating back to 1580, its 18th-century annex buildings characterized by sgraffito relief unseen to date, its carpentry from 1864 and its paving and façade from 1901 detached from the original were all restored. The building owners were granted permission to gain surface by extending the original façade to the street for realignment purposes. In fact, the building housed an interesting collection of historic floors and roofs, the earliest of which date back to 1580, with subsequent additions from circa 1750, 1864 and 1914. The floors and ceilings from 1750 featured decoration characteristic of the period which helped fix the dating and which have been restored, despite their poor condition. The 1750 terraced roof summarily became a floor when the back of the building was built up in 1914.
Unintentionally, the historic building to be restored became a sort of museum for the evolution of housing in the historic center of Valencia, with multiple interesting phases of construction, building up and transformation. The project for the restoration of these three residential buildings has attempted to adapt to their past history, without destroying any of their construction phases. In keeping with the philosophy of organic growth observed throughout the history of the building, the aim was for this intervention to become yet another life phase for future generations to study and recognise. The generosity of the resulting spaces and the warmth of the recovered historic construction have resulted in three magnificent examples of subsidized residential housing dating back to the 16th century, a rare situation which ought to be far more common.
The entire project resulted in 23 subsidised housing units in the form of 90^m2 residential units with the maximum usable surface contemplated in current Spanish regulations. 20 of these housing units were new constructions (buildings A and B) while the other 3 were restored (building C). In addition, the two-storey underground car park below buildings A and B, the courtyard of building B and the street between them provides 42 parking and storage spaces. 23 of these belong to the subsidised housing units while the rest benefit the neighbourhood, which is very short of parking. This two-story underground car park below local water ground level, which is shallow in this coastal city, was a feat of engineering. This work also had to take care of the construction of floors below street level, calculating 3,000 ^kg/m2 of static load, and studying dynamic loads to allow road traffic. The total cost of the underground engineering work was high for this reason, but the work on restoration and new construction was much lower at a cost of approximately 1,000 ^€/m2.
The ground-floor commercial premises have been rented out to local associations among others. The housing units, which are municipal property and are currently being leased to low-income tenants, are proving their efficiency as regards sunlight and cross-ventilation. This makes it possible to avoid the use of air conditioning and heating during most of the year, as well as showing off the extensive outdoor surfaces in the form of continuous terraces and permeable paving, and the capacity of the architecture, -particularly in building B- to provoke and generate social relationships for neighborhood collaboration.

NOTES

1. See CARBONARA, Giovanni, Le integrazione dell'immagine, Bulzoni, Rome, 1976.
2. See DOGLIONI F., Nel restauro. Progetti per le architetture del passato, Marsilio, Venice, 2008.
3. These ideas were originally debated in Camilla Mileto and Fernando Vegas, "La lacuna e il restauro architettonico: il concetto di scala e le sue ripercussioni", Confronti 4-5, anno III (June-December 2014): 29-38.
4. See also: MILLETO C., VEGAS F., "Architecture related to the existing city", in Arhitektura, raziskave - Architecture, research, University of Ljubljana, Ljubljana, n. 1, 2007, pp. 13-18; VEGAS F., MILETO C., "Urbanism for the Middle Class in historic city centers", in Monu. Magazine on Urbanisme, Kassel, 2005, p. 21-23.
5. Camilla Mileto and Fernando Vegas, "The gap and architectural restoration: the concept of scale and its repercussions", Confronti 4-5, year III (June-December 2014): 29-38.
6. A very similar description of this project was originally published in VEGAS, F. & MILETO, C. "Subsidized housing units in the historic center of Valencia, Spain" in AR no. 1-2015, pp. 54-59.
7. A more detailed study on the design strategies used in the present project can be found in the article VEGAS, F. & MILETO, C. "Contemporary architecture in dialog with the historic city", to be published in Change Over Time 7.1 "Design and the historic environment", Spring 2018.

NOTES

1. See for example: CARBONARA, Giovanni, La reintegrazione dell'immagine, Bulzoni, Roma, 1976.
2. See for example: DOGLIONI F., Nel restauro. Progetti per le architetture del passato, Marsilio, Venice, 2008.
3. These ideas were already reflected in Camilla Mileto and Fernando Vegas, "La lacuna e il restauro architettonico: il concetto di scala e le sue ripercussioni", Confronti 4-5, year III (June-December 2014): 29-38.
4. See also: MILETO C., VEGAS F., "Architecture related to the existing city", in Arhitektura, raziskave - Architecture, research, University of Ljubljana, Ljubljana, n. 1, 2007, p. 13-18; VEGAS F., MILETO C., "Urbanism for the Middle Class in historic city centers", in Monu. Magazine on Urbanisme, Kassel, 2005, p. 21-23.
5. Camilla Mileto and Fernando Vegas, "The gap and architectural restoration: the concept of scale and its repercussions", Confronti 4-5, year III (June-December 2014): 29-38.
6. A very similar explanation of this project was already published in: VEGAS, F. & MILETO, C. "Subsidized housing units in the historic center of Valencia, Spain" in AR no. 1-2015, p. 54-59.
7. A more detailed study of the design strategies for this project is reflected in the article VEGAS, F. & MILETO, C. "Contemporary architecture in dialog with the historic city", to be published soon in the journal Change Over Time 7.1 "Design and the historical environment", Spring 2018.

CREDIT

PROJECT: 23 subsidized housing units in Valencia
FUNCTION: Housing
AUTHORS: Camilla Mileto and Fernando Vegas
LOCATION: Recaredo Street, between Roger de Flor Street and Maldonado Street, Valencia
DATE (DESIGN AND EXECUTION): Architectural design - 2005
Final design - 2007
Execution - 2008-2010
PHOTO: Fernando Vegas and Camilla Mileto
CLIENT: AUMSA (Actuaciones Urbanas Municipales S.A.)
BUDGET: 3.605.211 € (PEM)

REDITS

PROJECT: 23 subsidized housing units in Valencia
FUNCTION: Housing
AUTHOR: Camilla Mileto and Fernando Vegas
LOCATION: C/Recaredo between c/Roger de Flor and c/Maldonado, Valencia
DATE (PROJECT AND EXECUTION): Basic project - 2005
Final project design - 2007
Execution - 2008-2010
PHOTO CREDITS: Fernando Vegas and Camilla Mileto
CLIENT: AUMSA (Actuaciones Urbanas Municipales S.A.)
BUDGET: 3,605,211 € (PEM)