Conservation compatible energy retrofit technologies: Part I: Introduction to the integrated approach for the identification of conservation compatible retrofit materials and solutions in historic buildings

In 2017, the International Energy Agency (IEA) has made the built heritage the focus of a new collaborative research project. Within the Solar Heating and Cooling programme (SHC), 25 organisations (including public and private research institutions, heritage authorities, public administration, and industry) from 13 countries have joined forces in the IEA SHC Task 59/Annex 76 “Deep renovation of historic buildings towards lowest possible energy demand and CO2 emission (nearly Zero Energy Buildings-nZEB)” [5]. As Shah put it [6], “collaboration is used for solving problems that are too difficult or complex for an individual” (p. 216), and the identification of retrofit solutions that are compatible with historic buildings (and the barriers that prevent their implementation), is without a doubt an intricate task that profits from a multidisciplinary approach. The work carried out in IEA SHC Task 59 relied heavily on knowledge exchange and task sharing, profiting from the wide and varied group of experts collaborating in the project. Thus, the methods used in this study were based on an iterative process of information seeking, comparing and synthesizing, making decisions, and finally making use of the synthesized solution. This report presents the work carried out within the IEA SHC Task 59 project (Subtask C) to support decision makers in the adoption of conservation-compatible retrofit solutions for historic buildings, as suggested by the EN 16883:2017 [7] standard. The main objective of the study was to identify and evaluate examples that both satisfy the conservation of historic buildings and lower their energy demand.