In this work we suggest coating systems to renew the surface treatments on the windows and doors in the Dominican monastery in Zvolen. The anti-ageing resistance of the relevant systems have been verified experimentally. Wood specimens surface-treated with the proposed coating materials and subject to accelerated ageing were observed for their colour stability, water resistance, and surface treatment defects development. For the windows formerly treated with oily or alkyd coating substances, we recommend to begin with application of the impregnating agent OSMO WR 40001, and then to follow, according the suggested method, with a two-fold application of the protective glazing OSMO UV 420 serving as the top coating. This system exhibited the highest colour stability and the best resistance against water, in the case of application on spruce or oak wood substrates. The final darker colour hue harmonising with the colour hue of the original surface treatment should guarantee additional improving of colour stability.For the windows formerly treated with water-based coating substances, we recommend impregnation with the base impregnating material Böhme WAB and subsequent twofold application of the finalising coating material WoodCare UV -- as the substitute for the tested protective glazing BOHME LignoStain.