The first city hall in Porsgrunn was originally part of a farm called the Chamberlain Estate (Norwegian: Kammerherregården).

[1] The farm was later sold to Jacob Grubbe Ottesen in 1823 and then to the newly formed Bratsberg formannskapsdistrikt in 1838 for a sum of 2,200 speciedaler.

[6] The city hall building is in the Renaissance Revival architectural style with decorative elements taken from Art Nouveau.

The building has a symmetrical facade with a protruding central section that faces Storgata and out to Porsgrunn River.

One notable alumnus of the school is Carl Reynolds, founder of the Norwegian chapter of the IOGT temperance movement who caused the dissolution of the Porsgrunds Brændevinssamlag and is memorialized in Porsgrunn with a statue created by sculptor Trygve Thorsen.