The cottage attached to the lighthouse on Rock Island, the original shore base for Fastnet lighthouse, included a range of outhouses and storage buildings. Our brief was to provide additional bedrooms, bathroom and “a room with a view”. Given the sensitivity of the historic buildings, and the need to retain the navigation “daymark” wall of the original enclosure, consultations were held with the County Architect and historic buildings staff of Cork County Council. The proposals were approved, and retain the base shell of the original buildings, adding a glass box living space with panoramic views across Roaring Water Bay and out to Fastnet Rock. A ground source heat pump and heat reclamation ventilation system keep energy use to a low level.