The building was designed by Gunnar Asplund, one of Sweden's greatest architects of all time. When the extension was finished, a few surprised voices could be heard, should an institution as serious as a Town Hall be presented in this warm, open way? But this was exactly what the architect wanted to achieve. He wanted to create a light and harmonious interior to calm all the people who were worried about what the judges may decide. The exterior looks almost plain; the front facing Gustaf Adolfs torg is simple and serenely modernistic. But once inside the entrance hall, you're met by a warm spaciousness and a light organic feel. The light flows from the sides, through large glassed areas, and filters beautifully through all the delicately formed details of the interior. At the centre of the room is the large staircase, which with its low, wide steps almost forces you to slow down and walk straight. The idea was that the accused should be able to walk into the session chambers in a relaxed and calm frame of mind.
The greatness of the Town Hall Extension lies in the general atmosphere created by Asplund and his employees. With great care, they formed all the little details which together give the building its identity; nothing was to be left to chance. They paid just as much attention to the fixtures and fittings, which includes softly rounded furniture, lamps, and soft furnishings. The design of this building tells us a lot about the Swedish society in the 1930s, and its openness still feels modern today. This is one reason why there is a lot of debate now the building will get a new use.