Three European laboratories performed transmittance and reflectance measurements on the same coated glass samples and used different methods for the determination of the complex refractive index and thickness of the coatings. The optical constants of the glass substrates (taken from the literature or obtained by preliminary characterisation of the uncoated glass sheets) and coatings were used to simulate the daylighting behaviour of the coated glass sheets in real conditions as fenestration of a room. In spite of the discrepancies in the optical constants obtained by the laboratories for each coating the corresponding coated glass gave similar results for the luminous transmittance and reflectance obtained by integration of the computed data and for the illuminance inside the room obtained by applying a suitable computing program.
