Carrickfergus Castle is one of the most complete examples of Norman architecture in Northern Ireland, and of its type in Britain or Ireland. The project, which replaces the roof with an historically appropriate open ‘A’ frame hipped, green oak truss design, marks the first step in the restoration and protection of the castle’s Great Keep.
The principal trusses of the new roof are constructed from Irish Oak felled by Storm Ophelia in 2007. The timber trusses were used ‘green’, not requiring kiln drying, pressure treatment or chemicals, and oak-pegged without the need for nails or other metal fixings.
Timber ventilation lanterns provide a natural passively ventilated space beneath, mitigating the need for mechanical ventilation and its associated cost and environmental impact. Overall, the sustainable approach combines low energy in use with historic detailing, and traditional materials and construction methods with a low embodied carbon and little need for maintenance.
Judges said: “The work required a high level of craftsmanship which visitors will be able to appreciate, and as such the project supported traditional skills. The conservation architects, structural engineers, carpenters, and lead workers responsible should be applauded.
“The exposed roof structure and the additional volume it has created transforms the upper room of the Castle Keep into a dramatic space. It’s far more than a functional roof designed to withstand inclement weather. It will sustain and develop this building while ensuring its cultural history is not lost.”