The aim of BIOBUILD project is to develop and demonstrate fully bio-based building materials with thermal storage function that can replace high environmental footprint products. Our solution demonstrates functional incorporation of bio-based phase change materials (bioPCMs) into solid wood and wood fibres bound by plant oil resins, lignin, or fungal mycelia to produce novel bio-composite building materials with significantly improved thermal properties. The novel materials possess a high multifunctional performance, meet requirements for sustainable “green” production, and ensure end-of-life options and recycling. Environmental and social impacts and benefits are fully integrated into the life-cycle perspective.