Technical and energetic refurbishment of residential building S in Stuttgart built by architect Klaus Franz. During the refurbishment, the architecture of the building is preserved in its original state. Energy concept by Transsolar Energietechnik Gmbh

"For the residential house of Dr. S. in Stuttgart, which is built deep into the steep northern slope and can be reached via 40 steps, Franz used exposed concrete for the first time for a single-family house. The construction is double-skinned with sand-lime brick lining and a wooden roof truss covered with fibre cement shingles. The wooden window elements in upright and horizontal format as well as opening casements in different variations, which were specially developed by Franz for this purpose, are installed in it. This house also impresses with its careful surface treatment and elaboration of details. The development of the property, which Dr. S. had acquired in 1965 with a valid preliminary building application for the construction of a single-family house, was prevented by the city of Stuttgart by a two-year building ban, since the feeder road for the so-called south ring road was being planned over the property. In 1968, the Schwanenplatz Commission finally abandoned the project in favour of a tunnel project on Marienplatz, and so the building application could be submitted on 30 April 1968. Klaus Franz had been working on the preliminary studies and sketches as well as the design since 1966. The building permit was granted on 27 May 1968 and the topping-out ceremony took place on 17 November 1968. It was very urgent now, as the S. household with three children was bursting at the seams in the rented flat. The design of Haus Domnick in Nürtingen, built by Paul Stohrer in 1967, shows a formal-aesthetic similarity in the projecting concrete girders, which on the one hand are part of the supporting structure and on the other hand are shown as extroverted in form. However, the organisation and constitution of the entire complex is completely different. Whereas the Domnick house is almost horizontally set into the landscape as a single-storey building, the S. house is vertically oriented, taking advantage of the steep slope, with two basement floors, the lowest of which houses a granny flat and the technical facilities, and the first basement floor contains the swimming pool and an office. The ground floor, the main and only full floor, houses the kitchen and dining area, two bathrooms and three bedrooms. The top floor is reserved for living."

from: Busse, Anette S., Im Spannungsfeld brutalistischer Strömungen und liturgischer Bewegung - Bauten der Nachkriegsmoderne von Klaus Franz, p. 397, Karlsruhe 2019.