PARIS, FRANCE.- Growing understanding that the outstanding universal value of urban heritage goes well beyond the value of the individual buildings it contains, has created a pressing need for internationally accepted guidelines and criteria for the preservation of historic city centres. Conservationists, municipalities, architects and developers will address the issue at the Conference on World Heritage and Contemporary Architecture, which UNESCO and the City of Vienna are organizing in the Austrian capital with the International Council on Monuments and Sites (ICOMOS) and the Austrian Ministry of Education, Science and Culture, May 12 � 14. The decision to hold the conference arose from a debate at a World Heritage Committee meeting in Paris in June 2003 about the planned construction of three high-rise towers in the historic centre of Vienna.

The shift to a more holistic approach to urban heritage preservation was exemplified last summer when the World Heritage Committee*, decided to place Cologne Cathedral on the World Heritage in Danger List. The problem is not linked to state of the Cathedral but rather the development of high-rise buildings in its vicinity that change the place of this urban landmark.

�The preservation of cultural heritage,� explains the Director-General of UNESCO, Ko�chiro Matsuura, �is essential for two separate sets of reasons: because of its universal aesthetic and historic value on the one hand and because of its importance to the societies and cultures that are its custodians on the other. Cultural heritage provides a link between past and present and as such boosts individuals� and communities� sense of identity and social cohesion. In this way it also cements the foundation on which societies build their future.�

Preserving individual buildings and monuments while carelessly altering their urban environment causes these monuments to lose their meaning and, arguably, much of their value, according to the World Heritage Committee and the experts that advise it. Thus the 16th century archbishop�s palace and other outstanding achievements of Mexican baroque architecture in the Historic Centre of Puebla (inscribed on the World Heritage List in 1987) may survive the construction of shopping malls and parking lots in their midst, but the identity of this unique city centre, testimony to the meeting of European and American creative forces, may not.

Examples can be found from Kyoto to Cairo and London according to the Director of UNESCO�s World Heritage Centre, Francesco Bandarin, who insists that UNESCO is not interested in curbing development or modern architecture.

�The desire of architects to create overbearing signature buildings that disregard their environment is the problem,� says Mr Bandarin. �We want quality design that is respectful of the continuum of the urban context. As conservationists, we are equally sceptical about construction that destroys the identity of historic city centres and about mannerist architecture that apes the style of past centuries. City centres that developed over centuries need to remain legible with each stratum of their development testifying to its culture and stage of development. The identity of each stratum must be respected, as well as the identity of the whole, which is the fruit of the interaction between those strata.�

UNESCO and participants at the conference will be looking at ways to ensure that the development of historic cities is sustainable, and that investments in modern infrastructure and facilities do not make these cities lose the proven social, cultural and economic asset that their heritage represents.