A Scan-to-BIM Methodology Applied to Heritage Buildings

Abstract

Heritage buildings usually have complex (non-parametric) geometries that turn their digitization through conventional methods in inaccurate and time-consuming processes. When it comes to the survey and representation of historical assets, remote sensing technologies have been playing key roles in the last few years: 3D laser scanning and photogrammetry surveys save time in the field, while proving to be extremely accurate at registering non-regular geometries of buildings. However, the efficient transformation of remote-sensing data into as-built parametric smart models is currently an unsolved challenge. A pragmatic and organized Historic Building Information Modeling (HBIM) methodology is essential in order to obtain a consistent model that can bring benefits and integrate conservation and restoration work. This article addresses the creation of an HBIM model of heritage assets using 3D laser scanning and photogrammetry. Our findings are illustrated in one case study: The Engine House Paços Reais in Lisbon. The paper first describes how and what measures should be taken to plan a careful scan-to-HBIM process. Second, the description of the remote-sensing survey campaign is conducted accordingly and is aimed at a BIM output, including the process of data alignment, cleaning, and merging. Finally, the HBIM modeling phase is described, based on point cloud data.

Protocol Development for Point Clouds, Triangulated Meshes and Parametric Model Acquisition and Integration in an HBIM Workflow for Change Control and Management in a UNESCO’s World Heritage Site

“…The use of photogrammetry and laser scanners to study Heritage is especially interesting as it allows capturing highly complex buildings with a very high degree of precision without the traditional data collection’s limitations [ 16 ]. The integration of these techniques in the HBIM workflow is a step forward to guarantee our heritage’s preservation and maintenance and to design interventions on our heritage more respectful with the monument [ 17 , 18 , 19 , 22 ].…”

“…Nevertheless, there exists a traditional modeling that relies on three-dimensional models obtained by UAV and TLS to recreate buildings. In this modeling we obviously have to do a processing/study of the information that comes to us in which we synthesize it, mainly the constructive element’s geometry, to obtain a cleaner and more operational model [ 18 ]. These cleaner construction elements can in turn be exported to other calculation programs.…”

“…The approach adopted for the modeling was to establish a workspace in which we could visualize the wall’s remains undoubtedly preserved. This way, modeling from a distant scale to a close one [ 18 , 39 , 40 ], the military elements that were preserved in the cloud points were prioritized and discretized to allow making hypothesis about possible layouts. Approaching us from a far scale to a close one is an orderly methodology that helps us make decisions and in study these urban groups or urban aggregates [ 41 ].…”

The complexities of managing historic buildings with BIM

“…Challenges relating to 'levels of detail' (LOD) and the need to carry out digital surveys due to the lack of accurate information have been discussed in the literature (e.g. in Antonopoulou and Bryan, 2017;Arayici, 2008;Chow et al, 2019;Rocha et al, 2020) and this research has contributed to this discussion. However, there appears to be little research that has established the need to further understand the culture of managing heritage buildings; to understand not only the technical capabilities, but the processes and formalities in place for making decisions and implementing changes that have been created by their protected status.…”

“…Additional challenges in providing BIM4FM solutions for existing building, include: defining data requirements, roles and responsibilities for loading data into the model; maintaining the model, and lack of real-world cases and proof of positive return on investment (Becerik-Gerber et al, 2012). Furthermore, there is the need to digitise plans or undertake new surveys with technologies such as 3D laser scanning (Antonopoulou and Bryan, 2017;Rocha et al, 2020) to first develop the geometrical digital model into which management and operational information can be embedded. These challenges are further amplified when applied to the heritage sector, where Pellicer and Jordan (2016) highlight the absence of familiarity with digital tools and processes within this sector and the added complexities and deformities of found in the geometries of heritage buildings.…”