Abstract To enable the development of conservation strategies for valuable historical collections, an innovative non-destructive and non-invasive survey was conducted at an historical library (Classense Library, Ravenna, Italy) to assess how management scenarios may influence the future conservation state of the collections. For the first time, the results in terms of acidity and degree of polymerisation of book collections were elaborated using the Collection Demography dose-response function modelled for historic paper to predict the lifetimes of the collections in different environmental scenarios. Isochrone plots and demographic curves were elaborated to evaluate the fitness-for-use as a function of environmental and book conditions. The results show that the most sensitive items are books with iron gall ink and acidic (post-1850) books. These books are not predicted to survive a long-term planning horizon of 500 years in their current storage environments. The present results provide the decision-makers with two options for preserving the fitness-for-use of the collections: a preventive conservation with significant cooling of the storage environments, or an interventive conservation involving treatments such as deacidification.