Rosslyn castle is the medieval seat of the St. Clair family, one of the most prominent noble families in Scotland since their arrival in the 12th century. The remaining structures have a rich and violent history, first attacked in 1544 as a part of the ‘Rough Wooing’, an invasion of Scotland ordered by King Henry the 8th. The East Range building, an impressive residential expansion with Renaissance influences and the focus of the recently completed works, was added in 1622 and partially destroyed from a further attack by the Cromwellian army, led by General Monk in the later years of the 17th century.

As well as addressing the deterioration of fabric the new roof provides modern amenities with the provision of a new generously sized living room, kitchen, and bedroom with ensuite. Designed to subtly blend in with the existing form and materials externally, the structure of the roof is expressed internally through exposed douglas fir rafters and linings. New curtain wall glazing juxtaposes the existing stonework with a modern intervention, opening up views to the ancient woodlands surrounding the castle.

The project included extensive conservation and repair works to the existing fabric throughout, adopting a fabric first approach to improve the energy efficiency of the full East Range. Although extremely limited to what could be implemented due to the various statutory protections and decorative carvings and panelling, a key aspect of this work was addressing water ingress and reducing heat loss from the building. Specifically chosen for their breathable attributes, compatibility with the existing masonry, and low embodied carbon credentials a range of natural insulation materials help reduce the buildings space heating demand and provide a base for the new efficient heating and hot water supply.

A unique and exciting aspect of the project is the addition of new air source heat pumps located within the medieval vaults below the ground floor making the castle Net Zero Ready. Historically used as service spaces providing kitchens, bakehouses, and dungeons, these spaces are revived once more as modern-day services spaces operating as plant rooms. Cutting edge heat pump technology and historic stone vaults co-exist in a symbiotic relationship, both benefitting from each other and justifying the radical positioning of this innovative technology.

Client – Rosslyn Chapel Trust

Main Contractor – John Dennis & Company (Scotland) ltd

Structural Engineer – Narro

M&E Engineer – Harley Haddow

QS – Morham + Brotchie

Stone Masons – Laing Traditional Masonry