Tall timber buildings currently represent a sustainable solution for densely populated cities. Their main worldwide barrier relates to fire safety, and standard fire tests omit the fire decay phase. However, this is of crucial importance for timber structures because wood loses its mechanical properties at relatively low temperatures. Thus, the precise interaction between fire and structure needs to be understood because the temperature propagation through the load-bearing timber can unexpectedly lead to structural failure. FIReSafeTimber investigates key challenges related to the fire dynamics inside timber buildings and the resulting deterioration of the engineered timber mechanical properties using computational models and fire tests at various scales. FIReSafeTimber aims at developing performance-based methodologies for the fire-safe design of timber structural systems that include the effects of the fire decay phase.