Building industry is responsible for almost 50% of the world’s total energy demand. It takes more energy to operate buildings than it takes to run the manufacturing or transportation industry. In the drive for climate change, a lot of work is being done by policy makers for making new projects better aligned with environmental and energy conservation goals. It is not enough to only focus on improving the climate response of new construction. Work also needs to be done on improving the energy performance of existing building projects which will in turn, further reduce the CO2 footprint of the building operations industry. One way to reduce the energy consumption of existing buildings, is to add insulation to façade elements during building retrofitting projects. The purpose of this research is to shed light on probable options and benefits for adding insulation to traditional envelopes. This will enhance the operating capacity of buildings without the need for demolition or re-construction. This project demonstrates the energy efficient retrofitting of an old silk factory in the historic city of Valmadrera, Italy to act as a prototype project testing suitable options for adding insulation to existing structural systems. One of the biggest challenges for this type of upgrade is the porous nature of the existing building material and how it conflicts with the hygroscopy of synthetic insulation materials. The research suggests the use of organic insulating materials for the envelope elements. At the same time it also offers valuable suggestions for future explorations. This research has a high impact value globally, due to the vast treasure of historical architecture buildings which need to be preserved, but also need improvement in terms of their technological performance. Furthermore, it holds strong relevance for the Saudi Vision 2030 because preserving local architectural practices, materials and techniques is a significant part of the national motivation to preserve Saudi cultural identity.