In the literature of computer graphics and computer vision, single-image based 3D architecture modeling is a hot research topic. Focusing on repetition detection of urban architecture images, a novel algorithm for reconstructing detailed 3D architectures is presented for interactively generating large number of repetitive structures in an effective and convenient manner. The new approach consists of three steps. First, according to the parallel or vertical relations of sketch lines interactively drawn by the user, the coarse architectural model is reconstructed using an energy function optimization. Upon the texture information of the single input image, the horizontal and vertical repetitions on each architectural face are then detected and classified based on their bounding boxes. Next, according to the user inputted sketch lines of typical detailed structure, the 3D information of detailed concave or convex structures is calculated based on the projective relations between detailed structures and basic body of architecture. Finally, the other same type of repetitive structures are reconstructed automatically and their 3D detailed architectures can be generated. Experimental results show that the proposed method can conveniently and effectively reconstruct 3D detailed architectures from single image with high visual quality.