The role of metallic substrates as a heat sink for thin layer gold coatings in double-layered optical components exposed to the ultrashort pulsed laser was investigated with the focus on the impact of the gold layer thickness. A two dimensional FEMTO-2D computational code for solid metallic targets with two-layered assemblies has been developed. The model is then used to simulate targets response to fs laser pulses at near damage threshold fluence and to determine the target damage threshold depending on its structure and the substrate material. Considering temperature dependent optical properties of a gold allowed us to make quantitative estimation of the damage threshold unlike many other models. The simulations show decreasing heat sink effect of the substrate with increasing coating thickness until it becomes negligible for 200 nm gold layer. Preliminary results show that a maximum improvement of the damage threshold of about 10% compared to a pure gold target is predicted for 50 nm gold coatings on two substrate materials: copper and nickel. (C) 2017 Elsevier B.V. All rights reserved.