1912 an architectural competi- tion was announced. The winner was Gunnar Asplund with his proposal for an extension in classicist/baroque style. However, it took until 1934 before a decision was made to go through with the project. By then the original proposal had been amended several times and the style was now functionalist. The extension was completed in 1936. The facade is rendered and the internal walls are clad in wood. The interior is domina- ted by the large hall with its roof lights and glass walls facing the courtyard. In conjunction with the extension, the interior of the older Courthouse building was modernised. Gunnar Asplund was also commissioned to design furniture, lamps and fabrics for the extension.

The Courthouse extension is regarded as one of Asplund’s foremost works and it is nowadays internationally renowned.