The aim of this thesis was to test suggested coating systems for the surface treatment of windows. These were three-layered pigmented water-borne coating systems with a different combination of centre and top layers applied to a spruce wood. The colour stability and degradation effects of surface treated wood by the paints exposed to the UV radiation and rain in the process of accelerated aging were monitored. In all cases, the colour change of CIEL*a*b* of surface-treated wood, its morphological changes after ageing as well as resistance to wetting of its surfaces with standard liquids were monitored.All 9 combinations of tested surface treatments showed high resistance to photodegradation. The total colour difference E in six sets did not exceed 1. In the other three sets the total colour difference was slightly above 1.The roughness and waviness of the spruce wood surface were significantly reduced by its surface treatment and the difference in roughness in the fibre direction and perpendicular to the course of the fibres were significantly reduced, too. The effect of aging has not been clearly confirmed on the roughness and waviness.The coating systems tested showed good resistance to liquid water both before and after aging. After aging of the surface treatments, an increased frequency of defects was not observed, suggesting minimal degradation of coating systems.Based on the results obtained, the coating system with the central layer A and the topcoat N3 was the most stable. The coating system with the central layer C and the top coat N1 was the least stable.