Designed by Charles Rennie Mackintosh in 1895, the Lighthouse was originally a warehouse at the rear of the Glasgow Herald printing office. Beginning with the history of the Glasgow Herald Building, including its original façade and Mackintosh’s design ideas, this dissertation examines several aspects of its conversion to a public building. The scheme of the conversion by Page and Park Architects is also explored, including the transformation of the floor plan and the overall journey through the building. Additionally, this thesis compares spatial elements of the original building to those of its conversion. It includes interviews with Isi Metzstein and Henry Mckeown, together with drawings, floor plans and photographs.