Evaluation of Thermal Performance, Environmental Impact, and Cost Effectiveness of an XLam Component for Retrofitting in Existing Buildings

Renovation and retrofitting of residential buildings is a subject of strong awareness in Italy: the most part of the existing building stock is completely inappropriate in terms of structural rigidity in the event of earthquakes and in respect of the objectives of energy efficiency set by the European law. This research presents the design of an innovative system of structural reinforcement using CLT (Cross Laminated Timber) technology based on materials with environmental compatibility: an xlam panel comes attached by a metal structure into the outside or inside layer of the external wall of existing building; the stratigraphy also includes the insertion of the insulation, the net of new systems (hydraulic and thermal) and also the new window frames. The new component is studied for modularization and standardization to ensure simplicity and speed of installation, low cost of pure proving and assembly. The research focused on aspects relating to building physics and sustainability in construction in order to optimize the choice of materials: analysis on performance were conducted and simulations were performed on various kinds of insulation materials in order to find the best possible configuration in terms of thermal performance, environmental impact and cost effectiveness. The results were verified with the construction of a prototype that has been check with a thermal test. Finally, with the obtained data it has been verified the renovation of a case study with different measures of intervention.