The invention generally relates to a method of manufacturing a polycarbonate-based panel (sheet) intended for the construction of buildings, especially glasshouses (conservatories, greenhouses), and comprising a core layer and at least one covering layer. According to the invention, the method consists in making up a composition for the said covering layer by incorporating shiny metallic particles, of a mean diameter ranging from approximately 200 to approximately 500 mu m, into polycarbonate and coextruding the said polycarbonate covering layer, in order partially to decrease the light transmission of the panel and so as to reduce the greenhouse effect. The invention applies to the building field. <IMAGE>
