This paper presents the feasibility of combining geometrical survey and in-situ nondestructive testing for the structural assessment of historical earthen constructions, which has typically difficult and non-documented geometries, unknown and highly variable materials, not visible damage states, and non-well defined boundaries and diaphragm conditions. Particularly, this paper presents the results of geometrical and structural surveys that are being carried out in the church ‘San Juan Bautista de Huaro’ in Cusco, Peru, as part of an ongoing research aiming at assessing its seismic vulnerability. The church dates back to the 17th Century and represents a typical Andean adobe church. Regarding to geometry, novel techniques such as laser scanning and photogrammetry from drones were successfully integrated to generate an accurate 3D reconstruction, and a numerical model of the building for seismic analysis. This numerical model was preliminary calibrated considering experimental results from operational modal analysis tests. The calibration process showed the importance of considering the connection elements in the numerical model, as well as allowed a preliminary assessment of material properties.