The work provides fundamental knowledge for assessing old wooden structures and presents various renovation options. The third edition has been thoroughly revised, including a substantial expansion of the chapter on "Historical Wooden Structures," illustrated with significant examples from the history of timber construction and their restoration. A new topic is "Strength and Deformation of Old Wood," which is useful for calculating wooden structures. Additional updates include the calculation of wooden dowels, increased load-bearing capacity of beam ceilings, tables for quick sizing of connections in damaged beam heads, and determining the fire resistance of bending beams. The chapter on execution details, contrasting faulty and correct solutions, is particularly interesting for planners and carpenters.