New Integrated Knowledge based approachs to the protection of cultural heritage from Earthquake-induced Risk
Historical Cities

Old Akko (Aka; Acre)

Technical Specifications for the Conservation of Built Heritage in Old ‘Akko

Old 'Akko – Conservation, Development and Inspection

The ‘Città di Roma’ International Conservation Center in Old 'Akko, Conservation project

Conservation of the Knights Hospitaller Compound

The Rehabilitation of a Building Slated for Conservation (Building 50, Block 10)

Typologies of the Residential Buildings in Old Akko

Technological and Structural Aspects in the Conservation of Old Akko

Triple Arch Window (“Trifore”) Specification
Rehabilitation of a Residential Quarter in Old Akko
Ram Shoef and Yael Fuhrmann-Naaman

For the first time since the establishment of the state a residential quarter is undergoing rehabilitation and conservation in Old Acre. The Israel Antiquities Authority and the Old Acre Development Company, in cooperation with the Israel Lands Administration, initiated the rehabilitation and conservation in 2001.
The quarter – Block 10 – is located in the northwestern part of the city and includes c. 120 buildings in which there are c. 250 occupied apartments. It was selected in accordance with a government decision (Resolution 2659 dated 3 November, 2002 and Resolution 2793 dated 24 November 2002) as a national pilot for determining criteria regarding the conservation, rehabilitation and building of ancient/historic urban fabrics, while safeguarding the residential, commercial and tourism functions that exist within them.
The bodies involved in the project are: the Ministry of Tourism, the Prime Minister’s Office and Ministry of Finance, through the Government Tourism Company, the Old Acre Development Company  and the Israel Lands Administration.
Four sub-committees were established to implement the project: a budgetary committee, development committee, marketing committee and community affairs committee. The project’s steering committee included representatives from the following entities: the Israel Lands Administration, Government Tourism Company, Acre municipality, Old Acre Development Company, Israel Antiquities Authority and the residents.

Goals and Objectives

Map of Block 10
The Old Acre Development Company, Israel Lands Administration and Israel Antiquities Authority defined the goals of the project as follows:
· To implement a pilot for the rehabilitation of old neighborhoods in cities such as Safed, Tiberias, Ramla etc;
· To leverage Acre as a city of international tourism;
· To implement the conservation and physical rehabilitation of the buildings’ envelopes and motivate the residents to maintain their homes;
· To improve the quality of life and the living environment of the occupants in the block;
· To create an economic leverage for exploiting the building potential while preserving the urban fabric;
· To encourage the introduction of strong economic forces which will assist in the city’s development;
· To promote and market leasing rights in buildings and reduce the scope of protected tenancy;
· To enrich the tourists’ experience when they visit and “wander” through the old quarter which is alive and breathing, where there are sounds, smells, atmosphere and authenticity. [1]
The main objective of the project, which demonstrates the complexity of the rehabilitation of Old Acre, was to create an optimal balance between the need for the continued development of the old city and improvement in the residents’ quality of life, on the one hand, and the need to preserve the unique character and historic appearance of the city on the other.
The aim of this article is to present and examine the conservation aspects in the physical rehabilitation of the buildings’ envelopes that were tested in the pilot.

The Survey of the Quarter

Location of vacant buildings and privately owned buildings
In preparation of the project the Conservation Department of the Israel Antiquities Authority conducted an extensive survey of all of the buildings in the block. The aim of the survey was to learn the urban and architectural characteristics of the quarter and the physical-conservation condition of the structures. A card was prepared for each building on which are recorded detailed information about its conservation and physical state, details regarding the uniqueness of the structure and a value level classification relative to the other buildings.
The survey produced a data base that facilitated devising proper procedures and determining policy for the physical rehabilitation of the buildings. The results of the survey included:
A. Identifying buildings of architectural and urban importance in the block
B. Identifying buildings or parts of buildings that are available for use
C. Identifying buildings and regions in the block where the construction of new building additions will be possible
C1. Identifying illegal building additions and setting policy regarding the
treatment of them
C2. Indentifying building materials for use in new additions
D. Determining policy for the treatment of building facades and courtyards
D1. Identifying engineering problems and providing solutions that are optimal from the standpoint of conservation
D2. The treatment of architectural elements in the building facades

Summary of the Survey Data.
Block 10 extends over a total area of about nineteen dunams in which there are 121 buildings. One hundred and six structures are owned by the Israel Lands Administration, fifteen are privately owned, eighteen are unoccupied and sixteen buildings are partly vacant. Demolition decrees have been issued for twenty three hazardous buildings. The potential for building additions was identified in forty
nine buildings covering a total area of approximately 4,500 sq m. Two buildings (42 and 141) were currently undergoing rehabilitation.

Value Level Classifications and Principles of Intervention

Location of buildings and regions in the block where building additions can be approved.
Three value level classifications were defined for the buildings in the survey. Intervention principles were established for each classification level, based on various considerations, some of which are detailed below in the section dealing with conservation issues. The intervention principles were modified again during the course of the project.
The overall approach for all of the value level classifications is one that espouses preserving the use of the original building technology and the original elements: kurkar construction, pointing up the joints between the stones with lime-based bonding material, plaster on the interior and exterior of the building, wooden ceilings, balconies, and wooden door and window elements.

Level A – “Affluent houses” that have extraordinary architectural value which stands out prominently in the urban fabric. These houses include:
· Buildings that have a dynamic urban function which constitutes a landmark in the city such as a structure that identifies a square or main artery.
· Buildings that have the highest level of original construction quality and are very complete from a standpoint of construction style. These structures possess a characteristic typological feature: central hall house, captain’s house, courtyard house.
· Buildings that are rich in original architectural elements: marble floors, decorative ceilings and triple arch motif (trifor), of a high quality or unusual elements such as wall drawings or special stone items.
· The building plan and original elements are very well preserved and unambiguous.

Intervention Principle: in buildings of this classification we aspire to a high level of conservation and restoration of architectural elements such as openings and balconies. Likewise, we hope to dismantle modern additions and abstain from any new building additions. 

Louis IX Street – a sketch of the northern façade after future rehabilitation.
Level B - Buildings that have a high architectural value:
· Buildings that have a dynamic urban function.
· Buildings with a characteristic typological feature: central hall house, captain’s house, bridge house etc.
· Buildings that have high quality, original architectural elements that are characteristic of Acre such as marble floors, decorative ceilings and trifor windows.
· Buildings that are in a fine state of preservation. In buildings of this classification level we find changes that have made but they are not a hindrance in identifying the building’s plan and the original elements in it.

Intervention Principle: protecting and reinforcing the building by emphasizing its components. In buildings of this classification level we hope to remove wire infrastructures from the facades. We will implement measures to protect and reinforce the structure’s elements which are of architectural significance: balconies, stairwells, courtyard and existing additions. A new addition will be permitted as long as it does not detract from the original function of the building and its surroundings, does not harm its façade and does not harm the city skyline. 

Level C – These buildings are defined as “ordinary” and they constitute most of the city’s built mass:
· From an urban standpoint these are structures which do not stand in a space independently; rather they are part of a building.
· From a standpoint of planning and construction quality these structures have no special characteristics.
· These buildings have no original elements or they have few original architectural elements or poorly preserved elements.
· Their state of preservation includes changes at all levels: breached/sealed openings, additions, replacement of original elements with new ones and the use of modern construction materials.

Intervention Principle: rehabilitation of the building and adapting it for occupancy. In instances such as these we hope to reinstall wooden shutters and windows on the building. New building additions can be constructed in them as long as they do not detract from the building’s surroundings and the city skyline.


In order to test the principles of the project and its costs in a practical way it was decided to conduct a “mini-pilot” in which twelve buildings would be rehabilitated. The buildings were selected so as to represent a variety of conditions and problems which are anticipated during the rehabilitation process. Their selection was done based on an assortment of data: their location in the block, the existence of basic planning data – survey plans, buildings that have different value level classifications, a variety of maintenance conditions and buildings with different construction addition options (from the addition of a single room to the addition of a complete floor).

Conservation Issues

During the pilot we were required to address a number of problems and basic questions regarding conservation. Some of these are presented below:
1. The Planning Process
In a conservation project there are a large number of unknown components and consequently further planning is required concurrent with implementation. Unlike new construction where the planning determines the scope of the implementation from its outset, in the case of conservation, the more complicated the project is, the scope of the planning required during the project becomes greater.

That notwithstanding, how is it possible to minimize the unknown components in a rehabilitation and conservation project? The first step in the planning process is compiling a data base by means of documenting the building and conducting a physical and engineering survey of it. The broader their scope and the more preliminary information derived about the building as a result of this, the unknown component will in all likelihood be that much smaller.
Nonetheless, when we are dealing with the documentation and survey of a building that is currently inhabited there are limitations to all of the necessary physical checks that can be done, particularly those that entail exposing extensive parts of the interior. An example of this problem would the removal of coverings or peeling off plaster in order to locate the remains of an original window in a building. In circumstances such as these it is advisable that the planning of the project be designed in stages and it is desirable to avoid planning details about which information is missing that is likely to be discovered during the stage when the unknown components are exposed in the building.

2. Materials
Professional conservation standards call for a preference in the use of original material and technology.
Building materials. The construction in Acre consists of kurkar and lime-based bonding materials. Kurkar rock in Israel has been recognized as a nature value for conservation and it is therefore legally prohibited to quarry this stone, with the exception of a few quarries where it is possible to produce natural kurkar stone for construction. This fact has resulted in the high cost of the resource compared with modern industrial materials.
The question we had to cope with was: In which situation should we insist that the reconstruction be implemented employing original technology and where can we allow construction utilizing modern materials? Other questions arose in the wake of this question: With which materials is it possible to build and to what degree of intensity? These questions all have constructive, conservation and architectural aspects that will affect the city’s appearance and the degree of its authenticity.

Opening Fixtures. The opening fixtures that were built in the Ottoman
period were made of Cedar of Lebanon and Calabrian pine of
Mediterranean origin. [2]  Whereas in abandoned buildings it is still possible to find original window elements; in many of the buildings that were continually occupied the window elements were replaced and aluminum elements were installed in them in place of the wooden ones. Because of cost constraints and durability to withstand the climatic conditions the question arose regarding the material and the possibility of installing aluminum window elements as a more long-lasting material in the given environmental conditions. In accordance with the value level classification it was decided that in those buildings of high value the wooden elements would be restored and in the ordinary buildings aluminum elements could be installed.
It should be noted that in recent years they have begun restoring wooden ceilings in the city using wood and in a few instances window elements as well. Nonetheless, due to budgetary constraints, a compromise on the kind of wood that is used will in all likelihood turn out to be an incorrect decision from two aspects:
1. The material’s limitations will result in producing elements that are inconsistent with the desired level of restoration in buildings of high value.
2. The material will not withstand the environmental conditions over time, will therefore result in the replacement of elements and accumulated high costs or alternatively, neglect and damage to the quality of life of the tenants inhabiting the same buildings.

3. Illegal Building Additions
The scope of illegal construction in Old Acre is extensive. Considering the city’s world heritage status, it should be noted that the additions were not built in accordance with conservation criteria. In fact the law is not enforced and the quality of the additions spoils the architectural and urban values of the city. As part of the rehabilitation project, an agreement was signed between the Old Acre Development Company and the tenants of the buildings slated for rehabilitation that included a clause to “return the building to its previous state”, in other words, at the end of the rehabilitation the tenant is supposed to return to a building from which nothing is missing. For example if there was a dropped ceiling in the apartment, the tenant will receive an apartment with such a ceiling, even if above it there is an original decorative ceiling that is in a good state of preservation. In the absence of enforcing the law, and based on the agreement to “return the building to its previous state” it can be said that the general approach is one that favors the tenant.
Building 40-41, which was part of the mini-pilot, put this matter to a reality test. There was a hazardous, illegal concrete addition located inside the building. It was necessary to decide whether to demolish it or treat it as part of the rehabilitation, which meant dismantling it and rebuilding it. The tenant was offered an alternative for the illegal area with an additional larger adjacent space that was not being used. The tenant rejected the offer and insisted that the addition remained in accordance with the agreement and by virtue of the fact that he rented the property after the addition was built. After consulting with the official bodies involved, it was decided to leave the illegal addition which was treated as an integral part of the rehabilitation of the building. The addition was subsequently dismantled and rebuilt of wood and “Ytong” aerated blocks, while at the same time attempting to incorporate it in the structure from the standpoint of appearance. In the end the tenant was granted a renovated illegal addition and the apartment was enlarged into space that was offered him as a alternative.

4. Exterior Plaster
According to the surveys that were conducted by the Israel Antiquities Authority it is clear that most of the buildings in Acre were treated with plaster. The plaster was applied as a sacrificial layer in order to protect the buildings from climatic damage. Apart from the composition of the material, it is very important how it is applied since this will have ramifications on its long term durability, and in any event, the plaster in traditional construction requires regular maintenance. During the past two years a number of experiments were conducted using plaster in the city, some of them with industrial plaster, manufactured by prominent firms in the field, and some with mixtures that were specially made for this purpose.
At the beginning of the pilot project it was decided not to plaster the buildings because it was believed at the time that no such plaster exists that can withstand the environmental conditions. After removing the plaster remains from the facades of the buildings it was discovered that the masonry stones were in a very poor state of preservation, which necessitated the application of plaster. As we have stated, the plaster is the sacrificial layer that needs to be renewed on a regular basis. The matter of maintaining the buildings after the pilot project has not yet been properly addressed.

Other Issues

Building Maintenance
The collected experience in rehabilitating and conserving historic buildings ranks the maintenance of buildings as the key factor in protecting the structure’s building materials from weathering and the deterioration of its physical condition. Without maintenance on a regular basis the building has no chance of withstanding for any length of time the natural weathering processes. Maintenance is a factor which should be taken into account in the planning process and in the budgetary allocation of every project. In the pilot there was no planning reference for the maintenance of the buildings and in fact there is no guarantee that the buildings will be permanently maintained after the rehabilitation. 

Public Cooperation and Social Rehabilitation

The combination of a populated urban fabric with conservation and rehabilitation processes of the same fabric makes the tenants and the social issue an inseparable part of the process. Without the residents’ participation in the rehabilitation, conservation and maintenance processes, and the creation of a sense of belonging and obligation to the place and an awareness of its value, it will be very difficult for the official bodies to maintain the city at a proper level of conservation. These issues were scarcely or not at all addressed in the pilot.


In light of the experience that has been accumulated to date in the mini-pilot and in referring to the issues that we have raised in the article it is clear that the planning process in a conservation project is complicated and it is important that this reality be addressed in the project’s budgetary allocation. The desire to conserve the city according to high standards, tips the scales in favor of using original building materials. Nonetheless, in considering these needs: conserving the natural quarried substance, the costs of raw material and the desire to improve the quality of the residents’ lives, we think it is also correct to use modern building materials, which do not constitute a threat from a constructive standpoint to the existing buildings and are not likely to accelerate natural weathering processes.
As for the matter of illegal building additions, beyond its legal aspects, is a phenomenon that is first and foremost an expression of the residents’ housing shortage. When the process will include providing alternative solutions to these additions, without problems with earlier contracts, it will be possible to systematically demolish the additions as part of the overall rehabilitation process of the quarter and thereby improve the residents’ quality of life and revitalize the appearance of the city from the standpoint of conservation.
The property owner is the principal bearer of responsibility for maintaining the buildings, and this includes among other things renewing the plaster on the buildings; in the present instance the owner is the Israel Lands Administration through the offices of the Acre Development Company. The matter of maintenance requires a change in concept and budgetary preparation. We anticipate the buildings will need to be plastered once every two-three years in order to protect them from the weathering processes and so as to preserve the appearance of the city at a reasonable level, and this of course has ramifications on the quality of life of the city’s inhabitants.
Finally we recommend promoting a broad measure of public cooperation in Old Acre as an inseparable part of the continuation of the rehabilitation process of the city.

At the basis of conservation work is an assortment of information involving historical, urban and professional knowledge about conservation, on all its levels: conservation theory and approaches, documentation and architectural and engineering conservation planning, knowledge of traditional technologies, of methods and materials and about application techniques.
Conservation work within the framework of rehabilitating a living urban fabric calls for coping that is complicated and more extensive from the standpoint of planning, in which the conservation factor is only one component. The mini-pilot was intended to establish the series of issues that arise from the physical rehabilitation and it indeed set forth initial problems that had to be dealt with which had ramifications on the continuation of the project.
The Israel Antiquities Authority, which is entrusted with the conservation of built heritage, acts vigorously to promote rehabilitation. It is a party to the project and is engaged in the physical aspect of the conservation of the buildings. It is still too early to evaluate the contribution of the project to the rehabilitation and development of the city and to the maintenance of the buildings in it; these will only be tested over time.

[1]    These goals were presented by the project administrator, Mrs. Kemi Zariahn-Heller, in the Acre conference that took place in July 2005. The subject of the conference was “Theory and Practice in the Conservation of the Built Heritage of Old Acre”. It was organized by the Old Acre Development Company, Israel Antiquities Authority, Acre municipality and Western Galilee Academic College.
[2]   Lipshitz N. and Birger J. 1998. 


Lipshitz N. and Biger J (1998). The Use of Wood in the Building of the Land of Israel in
the New Era. In “For Man is a Tree of the Field”, The Trees of the Land of Israel: Their Characteristics, History and Uses. Pp. 189-211. Jerusalem, Ariel and Jewish National Fund (Hebrew).

Israel Antiquities Authority Archive, Conservation Files:
Sheffer et al (2001). Old Acre – Block 10, Residential Pilot: Stage 2 – Implementation  Plans (Hebrew).
Sheffer et al (2001). Old Acre – Block 10, Residential Pilot: Appendices (Hebrew).

November 2008

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