The practice of reusing old buildings is a phenomenon common to almost every historic period , mainly in long existing urban centres. The centre of Athens is a handy example.Here, a large number of civil services is housed in buildings originally designed for different functions. The financial factor is primarily responsible for the different use of many such edifices. Today, the expansion of urban centres, the dynamic rearrangement of activities in the cities and the progress of technology along with the realization of certain values – points of reference, all typical of the urban network, raise the issue of conservation of those buildings that have lost their original function .

The question of reusing buildings, which have been deprived of their primary function by dynamic city evolution represents an international

reality and an important architectural quest of our time. To cover new functional demands that will meet the new needs and the character of the area is a problem, which cannot be solved simply with the production of new buildings and replacement of the old ones. The continuously increasing number of empty shells, not necessarily conservable, creates a demand for a proper realistic policy, which will prolong their life and preserve them for the following reasons:

-They are reference points on the urban network.

– They play an important role in the continuity and completeness of the urban domain.

– They occupy considerable space that makes their replacement financially unprofitable.

– They usually exhibit a remarkable quality of architecture.

-They possess historical significance.

The introduction of new functions to an old building – shell with additions, demolitions and rearrangements, which will serve these new functions, employ the modern technology and

aim at renewal of the form of an urban area – with respect for its identity- presents a most interesting challenge for any architect.