This paper presents a comprehensive study on the criteria to identify ignition of wooden surfaces when exposed to incident heat fluxes in numerical simulations, being a research placed in the computational Wildland-Urban Interface (WUI) research field. In densely populated urban regions, wind-driven firebrands from burning vegetation and wooden structures pose significant hazards by igniting new fires that can spread rapidly. The fire safety of wooden structures is a critical area of engineering research because it directly impacts construction infrastructure, human lives, and the safety of entire communities. To address this issue, a scaled-down modeling approach is employed to better understand the heating/degradation mechanisms in wood samples. This research utilizes numerical simulations conducted with the Fire Dynamics Simulator (FDS) software to evaluate factors such as heat release rate, temperature distribution within the fuel, and the governing heating and degradation mechanisms. This methodological approach allows for a detailed examination of various heat transfer couplings - radiation, conduction, and convection - and their impact on ignition likelihood. Both localized heat fluxes (mimicking firebrands depositions) and cone calorimeter (mimicking nearby flames) heat fluxes will be considered as incident heat fluxes on the wood surface, with varying intensity ranges. The study aims to identify the most adequate criteria to consider the ignition of the wood fuel when exposed to incident heat fluxes in numerical simulations using FDS. The increase in temperature within the wooden fuel will lead to several physical phenomena, including water evaporation, char layer formation (which acts as an insulator) and oxidation, and the production of fuel gases, which can further increase the intensity of the incident heat. Accurately modelling these processes is extremely important. The anticipated outcomes are expected to enhance the understanding of fire spread mechanisms in urban interfaces and contribute to more effective fire safety regulations and urban planning strategies.