Finite Element (FE) numerical methods are particularly helpful in civil engineering applications, to assess the load-bearing capacity of existing or novel elements and systems. When applied to relatively simple glass windows, major challenges could arise from mechanical characterization and interaction of basic components of assembled systems, with a critical role in damage and failure detection under design actions. This is especially the case of extreme events like impact and explosions, where a multitude of aspects should be properly taken into account. This paper elaborates on some major issues and expected outcomes from FE numerical analyses carried out on composite ordinary windows, such as triple glass unit (TGU) windows, when exposed to blast loads, with evidence of possible numerical methods and damage/failure detection approaches, as well as critical performance indicators for response analysis.