The 20th century saw an enormous worldwide growth of the housing stock. In particular the building boom after WW-II, during which the housing stock in most countries was multifolded, focussed the attention of the housing sector primarily to the planning and realisation of new construction; the consciousness of the enormous maintenance and management task to come was still a far cry. The begin of the 21st century shows a completely different situation that urges for a paradigm shift. New construction in most western countries has faded down below an annual production of 1% of the existing stock, and often well below. Parallel to this, the ageing existing stock draws growing attention. The necessary investments in major repairs, renovation, adaptation and redevelopment count at present for a total turn-over well beyond that of new construction. Improving the energy efficiency to the required standards of tomorrow will give these investments a strong extra boost. Though the change from new addition to the adaptation and transformation of the existing stock is well under way, large parts of the construction and real estate practice seems hardly aware and to stick to business as usual: new constriction, if not in greenfields then in brownfields. The knowledge about how and when to successfully maintain, manage, adapt, transform and redesign has still a way to go. At the same time, the awareness grows that housing problems are only partly related to the physical supply side and solving them requires more than bricks and mortar. The paper illustrates the paradigm shift in Western Europe and explores the consequences for the future management of the housing stock.