Major seismic events occurring around urban centres often cause widespread damage to the building stock. Engineers are then required to perform safety inspections of these buildings. This process may be time-consuming and can cause residents or businesses to be displaced for a considerable duration even if the building is safe to occupy. Furthermore, other post-earthquake recovery phases, such as repair and demolition/reconstruction works, may not even initiate until the building inspection phase is complete. As such, the disruptions caused by post-earthquake inspection need to be considered when modelling building occupancy/functionality downtime. This study uses the data obtained from the 2011 Christchurch earthquake to develop a post-earthquake inspection duration quantification model. Firstly, the duration of the rapid assessment phase is estimated from the number of damaged buildings to be assessed, the total number of available engineers, and the median time needed for assessing each building. Secondly, the probability of a building being assigned a certain colour tag (White, Yellow or Red) is derived based on the extent of damage. Finally, both sets of information are combined to quantify the post-earthquake inspection duration. A case study is examined to demonstrate the application of the proposed model.