Outer walls are a crucial component of the building envelope, providing insulation and structural support. While they are originally designed to support axial loads, these walls can be subjected to extreme loads, like the ones generated by impacts and blasts. Unreinforced brick masonry walls are particularly vulnerable to these actions and pose significant risks when damaged, including flying debris and progressive collapse. Careful engineering judgment is required to evaluate their resistance and design their strengthening in order to address this problem. A 3D FEM-based meso-scale modelling strategy is developed to simulate the response of masonry walls to blasts and impacts. The models were created in a general-purpose proprietary FEA software package, by making use of material models available in it. Bricks were modelled as nonlinear solid elements, while mortar joints were modelled by contact interfaces with cohesive-damage frictional behaviour. The models were built and verified upon the findings of impact pendulum and quasi-static four-point bending tests, both conducted at RISE Research Institutes of Sweden under various wall configurations. Once validated, the ability of this modelling strategy to conduct blast simulations was demonstrated for one of the tested wall configurations. This numerical work complements the experimental work previously conducted at RISE to characterize the response of brick masonry walls under impulsive loads. The modelling strategy presented here can assist the analyst evaluate the resistance of brick facades to these loads, allowing for a more precise assessment of urban areas at risk of damage.