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.

In year 2016 M SORA has passed all the certification tests and gained the NFRC approval from NAMI institute, which has confirmed that M SORA products are applicable for the buildings where higher standards against the overheating of the buildings is demanded. Since then certification has been extended every year. NAMI is national accreditation and management institute, from USA, Virgina, which provides certification, inspection and quality assurance services provided to the Building Industry in accordance with International Guidelines as set forth in ISO/IEC 17065 & 17020. It specializes in Fenestration and Building Envelope Products, such as: Windows, Patio Doors, Entrance Doors, Glazing Wall Systems, and others.