CE mark is an abbreviation of French word "Conformité Européene". With CE mark M SORA company guarantee, that the products are legally put on market and fulfil requirements of European Union regulations and European standards.

M SORA acquired the ift-FEM certificate for calculating thermal transmittance of window frames (U_f) according to European standard EN 10077-2. The certificate was granted by the German ift institute in Rosenheim in 2014. U_f values are calculated using WinIso 2D professional software, one of the basic characteristics required for CE marking and calculating a window’s thermal transmittance (U_w). To date, M SORA is the first only company in Slovenia to gain the certificate.

M SORA holds three Passivhaus Institut certificates for timber windows Nature Optimo XLT and Nature E112 and timber-aluminium window Comfort E112.