The book encodes a vision for the actively sustainable management and development of the built environment by referring to the application of timber-based construction systems as additive solutions for the multi-purpose improvement of existing buildings. It translates this vision into an innovative methodology for the management of the entire building process - from design to production, operation, and maintenance - and the assessment of timber-based construction performances across the whole building life-cycle. This approach is based on a multi-dimensional analysis, which starts from the structure of the Active House (AH) protocol, improved through information-integrated digital environments and multi-criteria evaluation methods, such as BIM and Design Optioneering. During the design stage, indeed, it analyzes and compares different design choices, according to the DO method, until the definition and validation of the "As-Built" step, while in the operational phase, it refers to sensors-retrieved data to show the evolution of the building behaviour, accounting for real users' interaction, building performances decay and needs of maintenance, defining the digital twin of the building: a real Cognitive Building. Finally, the application of this methodology identifies innovative models of processes, products, and design of wood-based construction technologies, suitable to satisfy the needs of the 2D/3D construction layering for the sustainable transformation of the built environment.