The building and construction (B&C) industry, a significant global economic sector with a market size of $5.4 trillion in 2021, is projected to reach $11.1 trillion by 2031. Despite its significance, the sector is a leading contributor to environmental degradation, accounting for a large portion of global energy consumption, carbon emissions, natural resource depletion, and solid waste generation. ECOFUNC seeks to mitigate these impacts by advancing the use of carbon-negative polyhydroxyalkanoates (PHAs), produced by microorganisms using CO2 as feedstock, thereby reducing the sector’s environmental footprint. The project will establish the first EU-based circular value chains for applications such as ventilated façade cladding, ceiling tiles, and internal partition walls. This will be achieved through the development of recyclable PHA-based panels, offering a sustainable alternative to conventional, non-biobased, and non-recyclable materials. ECOFUNC will also integrate bio-based flame retardants, natural fibers, and PHA foams to create high-performance panels, targeting a global warming potential of under 0.5 kg CO2-eq/m² and aiming to reduce life cycle costs by up to 20%. Guided by sustainability frameworks, including the DNSH and SSbD principles, the project is driven by a consortium of industry leaders and research institutions working on PHAs, fiber processing, panel production, and product validation. As part of its broader impact, ECOFUNC will explore the use of panels in the automotive sector as a spillover activity. Furthermore, end-of-life strategies will be implemented, incorporating both chemical recycling to convert PHA back into virgin-grade material and mechanical recycling to re-purpose it for applications in furniture and automotive. The project will develop 11 technologies and 10 value chains aimed at transforming the B&C industry, demonstrating the technical and economic viability of PHAs in promoting sustainable material practices.