Urban renewal and urban development cannot be considered without due regard being paid to the social enivironment and, in particular, the nature of the city concerned. This holds especially for Vienna, which has a number of characteristics that distinguish it from other European cities of comparable size and character:
Austria being a federal republic and Vienna one of the nine autonomous provinces jurisdiction for housing can on a large scale be developed by the city itself. This includes legislation on housing subsidies, on housing renewal and on allowances.
Vienna is still characterised by the products of massive pre World War I housing construction. More than 30% of the current housing stock dates back to the period before 1918, and most of these houses are privately-owned rental flats (26% of the housing stock, in total 236.000 out of 910.000). Many of these flats are still insufficiently equipped. After World War I nearly all new housing has been carried out either by the city itself or by non-profit housing associations; thus private rental housing can - with very few exceptions - only be found in the oldest building sector.
The municipality itself participates actively in the construction of council houses to an extent virtually unrivalled by any other city in its class. This commitment has its roots in Vienna's pioneering municipal housing construction schemes of the interwar period. With approximately 230.000 municipal flats, the City of Vienna is Austria's leading landlord, while at the same time significant sums of money from public sources are made available to maintaining and improving the mostly private stock of old houses. Rehabilitation is organized by a semi-public non-profit body (WBSF = Vienna Land Procurement and Urban Renewal Fund).
The city authorities have never resorted to any large-scale clearing and renewal schemes or other "hard" measures such as have resulted in tenant protests, evictions, and social ghettos in many European cities.
by Wolfgang Förster, Municipal Department 50, Vienna City Administration
80 years of social housing in Vienna More about the objective: resident-oriented housing renewal l
http://www.gebietsbetreuungen.wien.at (vienna area renewal office) 
