Development of the Prototype information system supporting energy efficienEnergy efficiency in cultural heritage buildings is a challenging topic with the aim of reducing energy consumption while protecting the cultural and historical values of the buildings. Performing energy efficiency interventions on the mentioned buildings faces some challenges considering the limitations imposed by the law and building's safeguarding as a first priority. Examples of such challenges are: risk of making damages, lack of proper documentation, and project monitoring issues. Studying similar project, gathering analogous data and information from previously performed projects, utilization of architects' and intervention designers' experiences performing resembling projects, and using the advantages and disadvantages of performing a certain type of intervention on similar buildings can assist to tackle these challenges.