Deep renovation is defined as a one-step process to realise the full potential of a building to reduce its energy demand, based on its typology and climatic zone. It achieves the highest possible energy savings and leads to very high energy performance, with the remaining minimal energy needs fully covered by renewable energy. The current annual deep renovation rate stands at only 0.2% on average in the EU. This figure must drastically increase to reach 3% by 2030 and be maintained up to 2050 to meet the goal of climate neutrality defined for the EU. Therefore, there is a strong need for efficient and replicable solutions that accelerate these deep renovation practices and help achieve the 2030 and 2050 goals. Replicable systems are needed to allow rapid and wide deployment across Europe to reach a global target above 2%.

The focus of this session was on presenting a portfolio of easy-to-install envelope components for achieving near-zero energy balance and CO₂ emissions in buildings, providing a holistic solution for the total envelope — including façades, roofs, openings, and even renewable energy generation and storage. This included part of EASI ZERo’s development on bio-sourced and recycled insulation components, low-carbon paints and plasters, and lightweight, zero-emission frames for windows and doors.

The products in the material portfolio were developed to reduce embodied energy and CO₂ emissions, improve thermal resistance for insulating materials, and shorten installation time. The challenge then involved testing prototypes at laboratory and wall scale to assess the scalability of component and material performance. Building-scale numerical modelling determined the effect of the retrofit assemblies on building energy consumption and demonstrated how the products in the material portfolio reduced energy use at building scale, meeting the target value of a maximum of 50 kWh/m²/year.

The environmental assessment of EASI ZERo products began at material scale and was simulated at building scale, with the ambitious target of limiting carbon emissions to 4 kgCO₂/m²/year. This session provided a general overview of the Horizon Europe–funded EASI ZERo project, highlighting its objectives and the methodologies developed.