Transition metal (TM)-borides are well known for their high thermal stability, high melting points, and excellent mechanical properties. However, TM-borides suffer from poor oxidation stability at high-temperature ranges. Therefore, improving the oxidation resistance is of great interest for coated high-performance components, where both – a combination of mechanical and oxidative resistance – are particularly desired. Within this study an architectural approach to protect TMB₂ (TM = Hf, Ti, W) thin films from further oxidation is presented. For this purpose, different materials were investigated as protective layers on top of each boride system. The phase formation, morphology, and mechanical properties (e.g., hardness and Young’s modulus) of all as deposited thin films were determined using X-ray diffraction (XRD), scanning electron microscopy (SEM), and nanoindentation. Thermogravimetric analyses up to 1400 °C in synthetic air and long-term oxidation behavior of the synthesized films in ambient air at 1200 °C for 30 h was examined. High-resolution characterization techniques (i.e. TEM, HR-TEM, EDX) confirmed the good adhesion between the barrier top layers, as well as the unaffected diboride coatings and the substrates, respectively.