This presentation, "From Lignin Biomodification to Building Houses," was given by Dr. Sebastian Mayr (BOKU University, Department of Agrobiotechnology, Institute of Environmental Biotechnology) at the Paper Bioeconomy conference on 20 May 2026. It traces a research pathway from enzymatic lignin chemistry to applied building materials. The talk opens with the pulping process and introduces laccase, a multi-copper oxidoreductase enzyme capable of polymerizing or depolymerizing lignin depending on its source organism. It then details how laccase-mediated oxidation of lignosulfonates generates radical intermediates that drive extensive polymerization, yielding a modified lignin polymer (pLS) with potential uses in hydrogels, fertilizer coatings, adhesives, and films. The core of the presentation centers on the EU Horizon project BIOBUILD, which aims to cut building energy consumption by up to 20% using fully bio-based materials, including plant-oil bio-based phase change materials (PCMs) and lignin-based bio-binders. Results are shown for lignin as a binder in wood particle boards under both cold- and hot-pressing conditions, including mechanical strength testing against the EN 312 standard and a life-cycle assessment (LCA) comparing lignin, plant-oil, and mycelium-based binders. The work continues through pilot-scale upscaling of binder production and real-world demonstration in model tiny houses in Uppsala, Sweden and Lleida, Spain. A closing section presents mechanistic and analytical characterization of the lignosulfonate biomodification reaction (mass balance, elemental analysis, bomb calorimetry, NMR, FTIR, and TGA), followed by a summary of further applications of biomodified lignin across agriculture, packaging, medicine, and construction.