Initially, the building at Kaļķu iela 1 was constructed for the needs of the party school, but when premises were required for the newly revived RPI, the building was handed over to the university. When RPI received the Kaļķu iela building in 1958, it was not yet fully completed, and students at the time helped with the construction and furnishing so that the administration and faculties could move in.

Several faculties have been located in the Kaļķu iela building, such as the former Faculty of Construction, now the Faculty of Civil Engineering, and the Department of Architecture under its wing, now the Faculty of Architecture, as well as the Faculty of Engineering Economics and Management, the RPI Scientific Library, and even the Military Department, where students underwent military training during the Soviet era.

New student admissions and entrance examinations took place in the building, and RTU graduates received their diplomas there. "My first personal memories of this building - I remember very vividly how I took my entrance exam for the Riga Polytechnic Institute here in lecture hall 301," recalls Uldis Sukovskis, RTU Vice-Rector for Studies.
https://www.rtu.lv/lv/universitate/masu-medijiem/zinas/atvert/rtu-svinigi-atvadas-no-vesturiskas-ekas-kalku-iela-1