Ithuba Science Lab
The aim of the studio was to design and build another building for the Ithuba Skills College in Gauteng. Experiments with a light straw-clay construction that had been initiated by the University of Kärnten were continued; alternative materials for the structure had to be searched for.
During the 2-semester lasting course diverse working methods and structures were researched. The interior climatic situation in winter and summer was simulated in collaboration with the climatic engineering office Transsolar. The results were adapted the design. During the summer of 2011 the building was put up within eight weeks.
The science lab consists of a classroom for the twelfth grade and a laboratory for classes in natural sciences. A diagonal open corridor subdivides the building into two polygonal main spaces. The double folded pitch roof merges interior spaces and covered outside spaces into one volume.
The building is designed as a steel skeleton structure in combination with light cob construction walls. The construction rests on a reinforced concrete foundation with strip footings under the walls. The columns inside the walls are made of narrow flange I-beams that are horizontally connected depending on the height of the walls. In the final state all steel columns are completely embedded within the plastered straw-clay walls.
The light roof structure is based on the design grid of 1.2 meter taking into account the irregular positions of the supporting walls. The construction consists of triangular steel trusses, which were welded in a workshop next to the site.The roofing is made of corrugated sheet metal fixed directly on the top chords with self-drilling screws. The suspended ceiling is a timber structure with thermal insulation and plywood cladding on the inside. For the chosen light straw-clay method, straw was mixed with paste-like fluid clay, pounded and compacted in a sliding formwork. The result is a seamless, monolithic wall. Due to the high amount of straw, the walls offer high thermal insulation. The construction method provides great physical advantages, as it offers protection from strong insolation in summer while preventing the rooms from cooling out in winter. It regulates humidity and retains warmth and thus supports a comfortable climate within the rooms. The clay was extracted nearby the construction site.