Lumsden saw a high rate of tuberculosis amongst Guinness employees and knew that overcrowding was probably a factor. In 1900 he got the approval of the Guinness board to spend two months inspecting the homes of each Guinness employee to ensure that they lived in proper housing and to look for ways to prevent or treat the disease. The main Iveagh Trust buildings built in 1903–1905 were designed accordingly. He also studied the diets of the employees and established cookery classes for the wives of Guinness employees. Finally, he helped to set up the first Guinness sports club which included St James's Gate F.C.