In order to build sustainably an understanding of the place is needed – place in a sense that goes far beyond the immediate context and that takes account of value chains and the origins of materials. Since the 1990s it has been possible, by using the energy balance, to estimate quite precisely the amount of grey energy that goes into producing a building. )is opens up possibilities for ecologically responsible building – also in the city, using “vernacular” materials. For their wider use and application at a large scale it is most important that standards and guarantees, which have a major leverage effect, should be adapted accordingly. If old building techniques are used widely then “modern” construction materials such as steel and concrete can be employed where this makes sense: for foundations, for instance, or in bridges. Architects also have a role to play in this rethinking process, as do the ways in which their work is honoured such as competitions and exhibitions, which, not least, can serve the development of a new aesthetic.