Hårleman completed the Royal Palace in Stockholm, begun by Nicodemus Tessin the younger after fire had destroyed the medieval castle, in 1697.

The work on the interiors of the palace had a beneficial effect on the state of furniture-making and other crafts in Sweden and helped introduce the rococo style to the country.

On behalf of Uppsala University, he built the Consistory House (konsistoriehuset) and the conservatory building for the botanical garden of Linnaeus.

[4] Hårlemanska malmgård at 88A Drottninggatan street in central Stockholm was the Hårleman family house.

[5][6] Among his other works are Fredrikshovs house, Stockholm (1731), the Orangery, Linnaean Garden, Uppsala (1744), the main tower of the Holmentornet industrial works, Norrköping (1750), the Sätuna manor near Uppsala (1752), the Stockholm Observatory (1753), Hörningsholm Castle (c. 1746) in Mörkö in the Södertälje Municipality, and the "King's Gate" (1748), Tureholm Castle (1740s) in Trosa Municipality, Åkerö manor house (1752–1757) (completed by Carl Gustaf Tessin after Hårleman's death) in Södermanland, and the royal entrance to the Sveaborg island fortress off Helsinki, in Finland (then part of the Kingdom of Sweden), and which was featured on the Finnish 1000 FIM banknote issued in 1986.