The system of renovation frames is used for mounting of windows without the disassembly of old frames. The specificity of such windows consists in application of special renovation frame with the so-called masking profile which clasps a wooden frame creating a characteristic band from the inside, and at the outside one can apply special enclosing profiles. Masking profiles are of various widths; however, they can be also tailor-made to meet specific needs to prevent old frames from disassembly. Renovation frames are of reduced height not to significantly restrict glass surface while mounted on the old frame. Such assembly prevents from the danger of building façade damage, makes the assembly duration shorter, and reduces all finishing works.