This report presents a methodology for Life Cycle Assessment (LCA) and Environmental Product Declarations (EPD) for wood-based construction products, aligned with ISO 14040, ISO 14044, EN 15804, and EN 16485. It defines wood-specific material characteristics, calculation methods, allocation rules, and scenario settings to streamline LCA results and support both manual and tool-based EPD generation. The report provides generic input data, average Swedish sawmill production figures, and ecoinvent-based datasets classified by EN 15804. It also addresses challenges of data accessibility, digital integration, and international harmonization, emphasizing the need for methodological consistency. Developed through collaboration between IVL, Swedish Wood, and Skogforsk, this work supports sector-wide EPD tool development and improved transparency in sustainability reporting.