To limit the urban extensions and preserve the natural territory, city expands to wastelands or vacant sites. How new districts can be generated there?

Transforming by stages
Large industrial sites, partly or totaly obsolete, offer an environment for developing new urban districts. How their urbanisation be managed integrating time?
 

Bergamo (I)
Chalon/Saône (F)
Ghlin Mons (B)
Hamburg (D)
Lille (F)
Varberg (S)
Waidhofen (A)
Waremme (B)
 

Substituting with a new city quarter
Certain urban sites, without patrimonial value, require the creation of completely new urban areas. How can they be inserted and connected to their context?
 

Alkmaar (NL)
Dordrecht (NL)
Kirkenes (N)
Kleines Dreieck Zittau, Hradeck, Bogatynia (D-PL-CZ)
Lahti (SF)
Latina (I)
Milton Keynes (UK)
Pilsen (CZ)
 

Expanding urban limits
How can urban boundaries be structured strategically to answer the need of development?
 

Alcazar de San Juan (E)
Amstetten (A)
Gersthofen (D)
Maribor (SLV)
Valladolid (E)