This article examines the effectiveness of the use of brick arches in a non-standard case on the example of an architectural project of an extension to a private residential building. The purpose of this article is to show the relevance of the use of arches in modern private low-rise construction. The objectives of the article are to identify the advantages of a brick arch as a bearing structural element, to identify the strength capabilities of the arch to solve engineering and design problems that appeared during the design of a particular object, to determine the feasibility of applied design solutions. To achieve these goals, the methods of fragmentary architectural and construction analysis of a project case and strength applied calculation of the "Prussian" arch were used.