Development of EnergySkin: External Wall Temperature Control for Renovation

Achieving an energy-neutral building stock by 2050 requires sustainable energy-efficient renovation of facades. Conventional renovation with thick insulation reduces heat losses, but demands large material quantities, particularly when meeting high thermal performance and low U-value standards. Sustainable solutions should combine energy efficiency with resource conservation, low-carbon material cycles, and reduced gray energy. Dynamic exterior wall temperature control offers such a solution by active heat flow management. The EnergySkin project is developing a facade module for energy-efficient renovation. This module will integrate an electrically conductive coating for heating and photovoltaic in an insulating glass unit, which will be mounted on an existing opaque facade as part of a modular system for serial installation. The configuration enables active external wall temperature control whilst generating the necessary electrical power itself, thereby minimizing the heating demand and primary energy consumption of the building without additional CO₂ emissions. The system is being extensively investigated with respect to its thermal and electrical functionality, operating modes, and the integration of an electrical storage unit. Preliminary laboratory and component-scale tests have confirmed the feasibility of coupling transparent conductive coatings with insulating glass to achieve both passive insulation and active heating. Simulations demonstrate that integrated photovoltaic can cover the overall operational energy demand, enabling energy self-sufficiency. These findings highlight the potential of dynamic facade systems to surpass conventional insulation approaches by incorporating adaptability, renewable heat generation and circular design principles. Consequently, the project contributes to sustainable refurbishment strategies and supports climate-neutral building targets.