West of Lake Roxen, just outside Linköping, rises the stately ruin of Stjärnorp Castle, originally built as a manor house between 1654 and 1662. The complex consists of a four-storey stone building with a stair tower facing the park to the west, as well as a central gable (frontispiece) and two wing buildings facing the lake to the east. The architect was most likely Nicodemus Tessin the Elder. Stjärnorp Castle is depicted in Erik Dahlbergh’s Suecia Antiqua et Hodierna in an engraving from 1697.
In a violent fire in 1789, the main building and both wings were destroyed. While the wings— with the castle chapel in the southern one—were restored, the original main building remained a ruin and has stood exposed for more than 230 years since the fire. During the 20th century, minor maintenance work was carried out, including securing the masonry, shoring up window openings, and clearing vegetation. Stjärnorp Castle Ruin is a registered ancient monument and is protected by law.
In 2012, the Stjärnorp estate management invited to participate in a parallel architectural comission. The task was to propose ways in which the castle ruin could be safeguarded against further decay and preserved for the future, while also allowing a certain degree of accessibility. Wikerstål Arkitekter (acquired by Tengbom in 2017) was selected to continue working on its proposal for execution and design. Tyréns was responsible for the stabilisation of the masonry and acted as structural engineer for the project.
In recent years, an extensive and careful restoration of the castle ruin has been carried out, including both conservation of the masonry and new architectural additions. Externally, every effort has been made to preserve the experience of an untouched ruin. Behind the walls, however—supported on the same bearing points as the original attic floor—a protective roof structure has been constructed, and the uneven wall crowns and window parapets have been capped with carefully contoured sheet lead. Individually cut laminated glass panes have been installed in the window openings, fixed with specially designed window fittings. New exterior doors made of oak planks have also been added.
The roof structure consists of full-length beams, sawn on site from timber sourced from the estate’s forest. The collapsed central spine wall, which originally supported the floor structures, has been replaced by double beams resting on four deeply founded steel columns. The columns are clad in timber for fire protection.
The main staircase in the great hall has been manufactured as self-supporting stair sections and rests on a small number of steel columns placed between the ruined cellar vaults. In the stair tower, an elliptical spiral staircase is suspended, topped by a glass lantern. Both interior staircases are made of weathering steel with brass handrails.
The stair tower is accessed from the outside via a new oak beam staircase. In front of the courtyard façade’s plastered doorway surround—preserved since Tessin’s time—a double stone staircase in the Baroque style is currently under construction.

Location: Stjärnorp Castle, Linköping
Architect: Wikerstål Arkitekter & Tengbom
Lead Architect: Erik Wikerstål
Project Architect: Caroline Hahn Nilsson
Project Team: Ebbe Jensen, Martin Jakubowski, Thea Klitte, Rikke Hagedorf, Jenny Hennig, Jeppe Appelin, Simon Fast, Tarek El Ali, Hans Ahrland, Jonas Torle
Structural Engineer, Conservation and Heritage Consultant:
Tyréns and Balksten Byggnadsvård
Electrical Consultant: SWECO
Main Contractor: Miljöbyggarna Entreprenad, Linköping
Contractors: Byggnadssmide i Mjölby, Planglasteknik, Nordéns Skyddsglas, Åby Fasad, Berland Tak, Bravida, Svenska Hantverksplåtslageriet, and Stjärnorps Skog & Trädgård
Client: Slottstornet AB
Photograph Felix Gerlach
Construction Period: 2014–2025