The Kottarainen block between Eerikinkatu, Albertinkatu, Kalevankatu, and Abrahaminkatu stands out in the urban structure of Helsinki's city center in terms of its scale and temporal diversity. The oldest buildings in the block are three wooden houses built in the 1840s, opposite of which are the red-brick educational buildings designed by Onni Tarjanne for the Mechanical and Electrical Engineering Departments of the Technical University in the 1920s and 1930s. The Historical Building Survey of the plot number 33 was commissioned by the Helsinki City Premises Centre. The buildings are planned to be heritage listed in the updated masterplan of the block.