The use of reinforced concrete as a structural system played a significant role in the development of public housing buildings.  At the time, concrete was becoming a very commonly used building material, especially in the Modernist movement, due to its availability and structural qualities.  Also, it was a relatively cost-effective material to build with, which is why it was widely used in government-funded projects.  The characteristics of reinforced concrete were ultimately reflected in how these apartments were designed.  The strength and formability of the material allowed architects to have a degree of freedom in laying out the interior spaces and balconies, as well as dictating the architectural character of newly developed urban locations.  The moldable way that concrete is cast lends itself to the use of abstract geometric form, often featured in Modernist architecture.  Such became the language of many of these housing developments.  Although some project designers chose to a Modernist language by reflecting the existing character of the city, they still took advantage of concrete structure in the planning of interior spaces.  By using the material, they were not as limited to the use load-bearing walls as they would be with more traditional building materials.  This quality translated into a higher emphasis on functionality.