<p> The required performance of the surface of a building finishing material varies depending on the intended use. In the case of an exterior wall, in addition to “surface protection” and “durability”, “aesthetical appearance” is a common demand and is required for interior and exterior materials. Various methods are used to maintain the aesthetics of the exterior wall, however a low-contamination paint is generally used. The low-contamination paint is increasing the water repellence of the surface. This leads to a “self-cleaning effect” of the wall because of the super hydrophobic property of the used special paint. Although the effectiveness of these methods has been confirmed, they also affect the elements of the exterior wall design.</p><p> This study is performed to examine the effect of laser treatment regarding the water repellence and the aesthetical appearance of different kind of materials used for building exterior. There are three types of substrates: glass, stainless steel, and polycarbonate.</p><p> With reference in comparison with the surface irregularities of the lotus leaf of the plant, the three levels of groove width 10, 20, 40 μm and the four levels of depth 5, 10, 20, 40 μm were set as conditions for the investigation.</p><p> As a result, the metal became water repellent and the glass became hydrophilic, further improving the performance of the substrate. Only polycarbonate had a water contact angle in the range of 80 to 120 °, Further, a dirt acceleration test was conducted using a test body provided with a surface structure. From the above results, the following was found.</p><p> (1) The water contact angle can be changed by finely processing the surface of the substrate.</p><p> (2) When the groove-like surface structures are parallel to the direction of the flow of water, the color difference of rain streaks shows a small value at a water contact angle of 100 °</p><p> (3) It was confirmed that the combination of a substrate/material and a proper suitable surface micro structure to self-cleaning effect leads to a self-cleaning surface because of the super hydrophobic effect generated by means of a laser. In addition, the laser treatment has no negative impact on the aesthetical appearance of the modified material.</p><p> </p><p> The results of this study confirm, that a suitable microfabrication using a proper laser parameter can change the water contact angle of the substrate, and that the structuring of the surface has no visible effect on the aesthetical appearance of the material.</p><p> This indicates that a range of changed water contact angles, that could not be obtained with paint alone, can be generated</p>