The platform frame method of building timber frame structures is suited to both low-rise and medium-rise buildings. Many buildings up to six and seven storeys in height have been constructed over recent years typically for residential, institutional and hotel uses. There are a number of different conditions that need to be satisfied by the structural engineer during the engineering of a multi-storey timber frame building, including: The adequacy of vertical load paths The strength and stiff ness of the individual framing members Overall building stability and stability of the individual elements Robustness of the framing and connections Disproportionate collapse design This article introduces the composition and terminology used for platform timber frame building structures and describes the structural engineering checks which are required to verify the adequacy of the vertical load paths and the strength and stiffness of the individual framing members. There are several parts to the Timber Engineering Notebook for platform timber frame structures. Part 2 will cover horizontal stability, while part 3 will cover robustness and disproportionate collapse design.