This paper evaluates passive cooling methods to stabilise internal environmental conditions in a library building in the Coptic Monastery ‘Deir al Surian’ in the Egyptian desert. A comparison of the building (c. 1960) with vernacular architecture reveals how ignoring traditional building methods led to inappropriate internal conditions. The potential implementation of passive cooling methods is discussed in the context of requirements for the conservation of historic documents stored in the library. The methods considered are: reorganisation of the building functions and layout; evaporative cooling; enhanced (nighttime) ventilation; nighttime radiative cooling.