Arts 2021, 10, 60. https://doi.org/10.3390/arts10030060 www.mdpi.com/journal/arts Article Colors Inspired by Nature Analyzed in Two Residential Buildings Designed by Victor Horta Barbara Widera Faculty of Architecture, Wrocław University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, 50-370 Wrocław, Poland; barbara.widera@pwr.edu.pl Abstract: The aim of the article is to present the results of research on colors carried out in two residential buildings in Brussels, designed by Victor Horta: The Tassel House (1893–1894) and The Horta House (1898–1901), representing the Art Nouveau style for which the main source of inspiration was nature. The purpose of the research was to check whether the selection of colors in the buildings was also inspired by nature. The investigation applied methods of archive studies, literature review, field survey and comparative analysis of 251 color samples taken in the interiors and façades of the two houses, compared to the 307 color samples collected in the natural environment within the radius of 700 m from the two locations. The samples were described using the Natural Colour System ® chart. The research results revealed that the value of the color-matching indicator for the comparison of the color samples collected in the two examined buildings and the samples of predominant colors observed in the natural environment was determined at the average level of 92.5%. The conclusions from the study confirmed the significance of drawing inspiration from nature in the field of colors selection in the two analyzed buildings designed by Victor Horta. Keywords: architecture; heritage building; nature-based solutions; natural environment; European cities; building renovation; building envelope; Art Nouveau; daylighting; energy in buildings 1. Introduction The first two decades of the 21st century brought significant progress of knowledge in the field of natural sciences as well as a growing interest of all aspects of the natural environment. Several scholars analyzed the relations between nature and architecture (Agrest 2018; Widera 2018) and the changing perception of nature (Goodfellow 2019; Lovelock 2016; Sigurðardóttir 2020). The research described in this article addressed the topic of color in architecture with a special focus on the inspirations driven from nature. The article presents the results of the study on colors carried out in two townhouses and designed by Victor Horta: The Tassel House (1893–1894) and The Horta House (1898–1901). Victor Horta is regarded as the protagonist of Art Nouveau in architecture, while the edifices selected for the research represent excellent examples of Art Nouveau, the architectural style for which the main source of inspiration was Nature. Both heritage buildings selected for color analysis are located in Brussels, in two neighborhood districts: Saint Gilles and Elsene. The distance between the two buildings is approximately 700 m. Therefore, these two districts determined the area of the study. The specific purpose of the research was to check whether the selection of colors in architecture and interior design in the two analyzed edifices was genuinely inspired by nature. The investigation applied methods of archive studies, literature review, field survey and comparative analysis of color samples taken in the two houses, being the subject of research. The samples, taken both inside and outside the residences, were compared with the color Citation: Widera, Barbara. 2021. Colors Inspired by Nature Analyzed in Two Residential Buildings Designed by Victor Horta. Arts 10: 60. https://doi.org/10.3390/ arts10030060 Academic Editors: Jadwiga Urbanik, Agnieszka Tomaszewicz, Małgorzata Chorowska and Vladimir Slapeta Received: 27 July 2021 Accepted: 26 August 2021 Published: 31 August 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/license s/by/4.0/).