Humans first settled in elevated areas of the most accessible alpine valleys which offered the best conditions for housing and farming. These settlements eventually grew and slowly spread to the side valleys. 

Valleys of the easily reachable Rhone, Rhine, Inn, and Adige rivers have already lost most of their biodiversity value.

Natural habitats in the valley bottoms - riverbeds, floodplain forests, wetlands, alpine steppes - have been destroyed by expanding settlements. The transport infrastructure associated with this urban sprawl is a major barrier for many species in the Alps, preventing the establishment of ecological networks.  

Now, the Alps have reached a new level of urbanisation. The average living space occupied by a person has doubled since 1950. Even with minor population growth, there has been a sharp rise in the number of residential properties.

The continual expansion of cities, towns, villages, and hamlets are now threatening even the more remote areas in the Alps.

While the majority of Alpine communities lie below 1000 m, some cities, mostly tourist centres, are situated at higher altitudes. Holiday homes are being built almost everywhere. Apartment complexes or residential tourist buildings are significantly contributing to the rising level of urbanisation.