Folder H.35. Meetings, discussions, correspondence with architects, city authorities, colleagues leading up to contract. Folder H.36. Papers and correspondence, 1973-1975, on heating system. The original plans envisaged heating by pipeline from a plant operated by Stadtwerke Heidelberg. The Laboratory eventually had an independent gas heating system. The ensuing delays and alterations led to a rise in costs. Folder H.37. Correspondence, notes, plans, calculations…