The new multi-sport complex in São João da Madeira, Portugal, features a lightweight and fully demountable aluminum structure covering approximately 4,103 m² of padel and tennis courts. The slender structure, composed of customized aluminum profiles, trusses, and steel bracing, was analyzed in RFEM 6 with particular focus on global stability, second-order effects, and serviceability. The structural analysis was performed using the finite element software RFEM 6, which allows for the consideration of geometric non-linearities and the stability checks essential for lightweight aluminum structures.