The city of Stockholm is an interesting example for special challenges in urban development because of its geographical location: The city is built on 14 islands, connected by 53 bridges. 30% of the city’s surface is covered by water and another 30% by green spaces and forest. The city is surrounded by over 24.000 small islands, called Stockholm archipelago. Founded in the 13th century, urban development had to face geological changes. Through strong ground movement, parts of the city that were islands a few hundred years ago, belong to the mainland now. Apart from climate and geological challenges, Stockholm has an extremely tensed housing market. Most of the private rental apartments can only be kept for about 4 years. For the right of long term stays, long waiting periods on waiting lists have to be previewed.