Abstract
Interventions related to the use of historic buildings, in addition of rehabilitation, are known in other different terms including revitalization, empowerment, adaptive reuse, etc. However, so far, ther is no research has been done on these terms of interventions by Iranian academics, and this multiplicity of intervention terms and, at the same time, lack of clarity in the concepts, differences between them and their international equivalent terms, has caused confusion among the researchers. The purpose of this paper is to analyze these concepts and other concepts related to reuse historic assets and to determine their relation to each other. In this regard, while studying prerequisites and requirements of functional interventions, different approaches to the subject at the international and national levels are surveyed and the different types of functional interventions in these buildings are analyzed and compared. In order to do the abovementioned, the analytical-descriptive method was used in the first part. In the next section of the article, a comparative study based on logical reasoning has been used to examine the relationship between different reuse interventions. From the findings of this study, it can be noted that the major differences between the various terms in the scope of reuse interventions are due to two major issues of “different word formation in translation” and “belonging to different time and place coordinates”, while they have common underlying concepts and all emphasize on the “role of existence a use in a building in its sustainable conservation”, “the necessity of adapting new uses with cultural significance, values and authenticity of the historic monuments” and “adequately meet to the needs of contemporary life in these buildings.
Keywords: Compatible, Resuscitation, Rehabilitation, Empowerment, Compatible Reuse.

Introduction
So far, few studies have been done on this topic in domestic research in Iran, so that there is no consensus in many of issues in this field especially on terms. Thus, we certainly need to do extensive and in-depth research in this regard, but its prerequisite is to study on the basic concepts of the subject; Knowing that what issues have been considered in the interventions in international literature?
The main purpose of this article is to explain the concepts of this field, in this regard, addressing the reasons and requirements of functional interventions by looking at international documents and charters is on the agenda; Then the different approaches in this field in international and domestic literature are explained and finally the main field of the article is to identify the types of functional interventions through comparative comparison.
Addressing this issue, in addition to the fact that the existence of function in a building ensures the survival and conservation of the building, is also important in terms of sustainable development and environmental issues. Also, considering that while functional interventions can provide protection for the historic building, it may also cause irreversible damage to them, it is vital to determine the necessities and sensitivities for the conservation of historic buildings in this process.
The present article specifically seeks to answer the questions about concepts of different types of functional interventions, their relationship between each other and their different uses. Also, it is going to clarify what is the relationship between the domestic terms of interventions and their international equivalents?
The present article is a basic research that seeks to expand the knowledge on the subject of “rehabilitation” by explaining and analyzing some of the concepts, resulting from library studies. In this regard, first the different aspects of functional interventions have been explained by “analytical-descriptive” method and then by using “comparative comparison” method, the different types of domestic and international definitions provided for functional interventions have been defined and compared.

Conclusion
The following results are obtained from reviewing and comparing the definitions provided for functional interventions and based on studies:
Despite the fact that in most translated literature, the term “Rehabilitation” is equated with “Tavanbakhshi” or “tavanmandsazi”, but considering the common use of the word “Ehya” in Iranian academic and professional circles for this type of intervention, it should be accepted that the term “Ehya” is the proper translation for this kind of intervention; but it seems that because “Ehya” has been used for the urban intervention of “revitalization” at the same time in many academic papers, it made some scholars to find out a new equivalent for the “rehabilitation”. Overall, it can be said that although in recent years translating the term “rehabilitation” into different equivalents has caused confusion and has produced different literature; but comparing the definitions reveals that all these terms are different equivalents for the term “rehabilitation”.
Regarding the relationship of “rehabilitation” and “adaptive reuse”, some such as “Deathridge” (2012: 5) argue that in “adaptive reuse” the use of the buildings definitely change to new uses, while a “building may be rehabilitated to its former purpose or adapted to a new use”, therefore “all adaptive reuse is rehabilitation, but not all rehabilitation is adaptive reuse.” However, not all researchers believe this, and a comparison of the definitions provided for these terms, which despite all their differences, all have the same concepts which emphasizes “adaptation of buildings to appropriate and compatible use”, shows that these measures are no different but they simply belong to different times and places.
Regarding other relevant interventions, it can be said that changing the term does not necessarily change the action; as “Douglas” (2006: 1) believed “There are many other different terms that are used to describe interventions to a building that go beyond maintenance. Words such as ‘refurbishment’ or ‘rehabilitation’ and ‘renovation’ or ‘restoration’ are occasionally taken as being synonymous with one another, even by some in the construction industry.” Also in this case “Markus” (1979) noted that “in the world of building the terms “rehabilitation”, “conversion”, “remodelling”, “restoration”, “reinstatement” and so forth are unhappily confused.” (ibid) In addition, Wilkinson (2014: 4) confirms this claim and adds terms such as ‘retrofitting’, ‘modernisation’, ‘re-lifing’, and ‘recycling’ to the abovementioned.
Some of these words in different places are considered equivalent to a specific concept due to their common use; “Refurbishment”, for example, has gained widespread use in the UK as the most popular term to describe a wide range of adaptation work; however in the USA “Remodelling” is commonly employed as an all-encompassing expression for these works. Also “occasionally some ‘building adaptation’ terms are used together. Certain construction companies, for example, advertise their services as ‘specializing in renovating and refurbishing old homes’. Other contractors use the expression ‘extensions and renovations’.” (Douglas, 2006: 1-2).
Overall, as mentioned, there is several terms for functional interventions in historic assets in Iran, which although the multiplicity of these terms has confused researchers, but further study of their meanings shows that the focus of all these measures is on adapting the buildings to the appropriate and compatible use regarding to cultural significance, authenticity and values of the building; and the formation of different terms has been more due to the two issues of “different word choice in translation” and “belonging to different spatial and temporal situations”. In this regard, it can be said that in domestic literature in Iran, “Ehya”, which is equivalent to “Rehabilitation”, is the main keyword on which the specialized literature is based, but “adaptive reuse” is also a newer term which originates from the USA and Canada and gradually has spread around the world and today is one of the main keywords in this field. “Adaptation” is also a term which includes all interventions related to the functional interventions of historic buildings. In general, it seems that the agreement of the scientific and executive community of the country on the term “Ehya” and the formation of institutions and documents on the basis of this term, requires that focusing on this concept, handle the disagreements to be able to expand its aspects and essentials in the future researches.