Comparison of surveying techniques for the built environment: A literature review and practical evaluation

Abstract

The rehabilitation of buildings and old structures is becoming more frequent in developed countries, but information about them is often limited. The basic necessary information consists of the geometry of the elements, to which other attributes such as the state of conservation can be added. This paper evaluates geometric survey techniques in which non-invasive methods are used to collect detailed data on buildings, structures, and their surroundings. These techniques enable the generation of 3D digital models from point clouds representing surfaces, and may include properties such as colours and textures. In this research, survey techniques and their associated equipment are first identified. They are then grouped and compared, in order to summarise their benefits and limitations. Following this, a practical evaluation based on four small-scale case studies comprising several tests was conducted in indoor and outdoor environments. The experiments were intentionally limited in scope and equipment availability and were designed to provide comparative evidence under real-world conditions rather than a comprehensive validation of all surveying scenarios. The qualitative and quantitative results were analysed and compared with findings reported in the literature. The findings indicate that when choosing the most suitable technique for obtaining an accurate and high-quality model, it is necessary to consider the characteristics of the construction and the requirements of the survey to be carried out. Laser scanning gave results with better accuracy and consistency; in contrast, photogrammetric surveying was found to be highly dependent on the on-site conditions, with a non-negligible variation in accuracy, although photogrammetry may offer a favourable cost-benefit ratio under suitable acquisition conditions.