Protocols for Tracking Information Content in the Existing BIM

Preface

In the last decade, digitisation has transformed representation methods and tools, leading to an enormous increase in the quantity and quality of data and the variety of products. In new construction applications, the use of BIM systems has seen a consolidation in procedures and the identification of standard methodologies.

However, the effectiveness of a BIM protocol in the field of built heritage remains debated. The latter is characterised by its uniqueness, which makes it difficult to imagine the application of an approach created for the standardisation of representation processes, in a perspective that reflects the historical period in which time-saving implies cost-saving. For this reason, BIM is the subject of criticism and scepticism as to its effective use. The description of an existing asset poses limitations that require an in-depth study of the purposes and modelling methods.

Academic research in the field has the task of investigating the possibilities and working methodologies that can have a valid implementation within the revolution that is taking place in building digitisation practices.

Another limitation of these protocols applied to the built environment is the exchange of information, which is difficult within a system that, by its nature, is fragmented because it is composed of heterogeneous operators with complementary functions.

In the management of the architectural heritage, despite the consistent technological evolution, the process of computerisation is not homogeneously distributed and is still poorly integrated in the public authorities in charge of control. The interchange of data mostly takes place through files in formats made standard by the market and used too casually despite their specific peculiarities, neglecting the qualitative loss of information that can occur.

The state-of-the-art at an international level shows a renewed interest in the unification of technical regulations on BIM and the innovation of asset management and representation protocols, paving the way for the definition of IT procedures related to restoration or renovation. In the specific case of existing structures, although cataloguing methodologies for conservation and reuse are consolidated and tested, rarely are the geometric, documentary and iconographic components linked together effectively.

Consequently, there is a lack of the necessary osmosis, which is fundamental for the proper transmission of knowledge, between the areas more closely related to the design and execution of works and the sectors operating in the administration, protection and management of Cultural Heritage.

In the field of architectural survey and drawing disciplines, the application of a methodology that can respond to the need for continuous updating of data, through the structuring of BIM digital models, is in line with the innovation of electronic protocols that are becoming a regulatory tool thanks to the spread of international frameworks.

In this articulated panorama, the present work investigates the relationships between digital surveying and the construction of 3D databases, delving into the aspect of transforming the metric data of the point cloud in a parametric model for the existing heritage, supported by an analysis of the different reality-based detection techniques: from topographic mapping to detailed survey.

After outlining a coherent workflow, the issues of traceability of information content along the supply chain and the evaluation of the accuracy of both the survey and source-based modelling phases are explored in depth. The operations mentioned are basic requirements to ensure the upgradability of data and the possibility of reuse.

This is a topic that is still little explored, but which is coming to the fore thanks to the indications in the recent UNI EN 17412-1:2021 standards. In this volume, an attempt is made to unravel the skein and shed light on the international technical regulations, which are often characterised by a lack of organicity. Thus, all those tools are sought that are already perfectly codified and only need minor updates to respond effectively to the problem of traceability. In this way, it is possible to streamline procedures and optimise the work of professionals working in the field of heritage documentation.

This book, therefore, stems from a collection and synthesis of applications related to a specific case study, useful for consultation by scholars, engineers, and architects. The hope is that the text can be a base for the necessary theoretical study, but at the same time can represent a kind of knowledge transfer manual, in which to look for practice suggestions.

Jacques Laubscher

Former Head of the Department of Architecture and Industrial Design

Tshwane University of Technology

Victoria Ferraris

Adjunct Professor at the Department of Architecture and Industrial Design in 2009 and 2013

Tshwane University of Technology

Abstract

It is now 49 years since Eastman theorised what would become known as BIM: Building Information Modelling. Despite this, we can observe that the methodology, together with its associated tools, is still considered an exception to established practice, an eternal novelty with clearly something unfinished.

If we exclude a few excellences, such as the United States and the United Kingdom, and countries vying to keep up, such as France and Italy, there are still a lot of regions where BIM is completely unsystematised. As a result, it is first implemented in large design studios and public projects and only then, with difficulty, does it spread to the rest of the market.

While we could accept the idea of a silent revolution that takes time to gain a foothold, it is now clear that too much pressure has been applied to the AEC (Architecture Engineering Construction) sector, which was not ready for such a radical change, first in thought and then in practice. Putting this aside, the time required for innovation is in any case not compatible with that necessary for digitisation in other sectors, generally between five and ten years (NBS’ 10th National BIM Report).

The Fourth Industrial Revolution (Industry 4.0), focused on data and connections, has brought out the limits of our domain, which is unable to keep up with other sectors of production and services. While it is right that transition can only be triggered by an awareness of needs, it is also true that managing interactions with external fields is an equally relevant factor.

This paradigm can also be extended to the associated tools, which must interact and be connected to the web to ensure proper data management and the realisation of the so-called digital twin. The new AEC software has metabolised the BIM methodology, or at least it is oriented towards it, although consistent and significant examples are still linked to large projects and established professional actors.

There are no reports or analyses in the literature that disprove the inevitability of BIM for any product (infrastructure, buildings, etc.), application (new construction, renovation, restoration, etc.) or stakeholder (clients, designers, companies, etc.). Despite commercial maturity and a broad spectrum of technical standards that seem to be converging towards organicity, the most common image is that of an unfinished revolution.

Apart from the abovementioned excellences, we can identify an uncertain use of tools, very specialised, based on approximations through trial and error, accompanied by a limited knowledge of the IT (Information Technology) and complexity behind the software front-end. They are compounded by the weaknesses of a mistaken approach to change. On the one hand, there is a fragmented experimentation, which has difficulties in dissemination and systemic interaction, and on the other hand, we have the inefficiency of a top-down body of rules and laws, which risks excluding the bottom from participation.

In this panorama, research can play a fundamental role in the dissemination and systematisation, encouraging proper use of tools that can go beyond contingent needs. A hybrid approach of practice and theory, spiced up with training in the basic principles of IT, might be the desirable solution.

If the AEC sector is not able to innovate and govern digital change, it will have to undergo it to adapt to this widespread need. The first experiments, which were strongly linked to IT innovations and software tools, have given way to an excessive theorisation of the method which leaves us without any practical feedback, a sign of general uncertainty in the direction to be taken.

A representative example of this lack is the answer to the need for sharing data, information and thus knowledge, a problem common to all disciplines. In the field of BIM, this critical issue is ‘solved’, in conceptual and normative terms, with the introduction of a dedicated digital environment, defined Common Data Environment (CDE) first in BS 1192-1:2007 and later in PAS 1192-2:2013. Since then, CDEs described by other standards have been proposed, together with those developed by the academic world and those promoted by software houses, capable of responding to the problem in different and not always compatible ways.

Similarly, the interaction between instruments cannot be left to the intensive work of the operator due to the inefficiency of the software. The lack of an AEC ontology cannot be solved by using only IFC classes, which are incapable of pursuing targets incompatible with their nature. The transition to object-oriented programming, with its specific elements, has not been completed in work scheduling and cost management appliances.

Not all the seven ‘dimensions’ of BIM can be realised. For example, we do not have Project Management (PM) tools capable of independently predicting possible interactions between modelled objects. When BIM is employed as a graphical support for administration, it does not always blend perfectly with data storage systems. Its tools are too often used to replace the old 2D representations (PDF or DWG), without the perception of a strategic and not just instrumental change.

Most of the focus for BIM is on new construction, with protocols being developed to make the production process more efficient. Its use concentrates on planning, design and integrated project delivery for buildings and infrastructure, but since recently, research interest shifted from earlier lifecycle (LC) phases to maintenance, refurbishment, deconstruction and end-of-life considerations, especially of complex structures. Promising benefits of efficient resource management motivate investigation to overcome uncertainties of building condition and deficient documentation, prevalent in existing heritage. A BIM protocol for the latter might end up being very similar to the one applied for new constructions, but this might not be the most effective way of approaching the problem. The public debate on BIM is often confusing and on occasion lacks a clear vision of final goals.

To completely reformulate the problem and articulate it appropriately could be the first step to take to clarify the scenery just described. A tool in the gearbox of creative thinking is the so-called Kipling technique, whose archetypes can be found in the structure used by Greek-Roman philosophers to formulate the argumentations. It is a list of six seemingly trivial questions (5W+1H), yet they oblige you to re-examine each element or point of view related to a specific topic. The field of documentation and management of the built heritage is not an exception and a deepening of the details, developed by asking the right questions, can give an overview of the situation.

To be extremely concise, it can be observed that in the sector of architecture, engineering and construction (Where?), data flows are today (When?) disorganised and productivity levels do not excel. This is because the world of construction, by its nature, is characterised by a certain level of disorder that does not allow the coordination of the figures involved in processes (Why?). Technicians (Who?) must therefore work hard to develop and adopt digital systems aimed at the effective and efficient management of the information at stake (What?).

If the ‘Wh’ questions help to clarify and organise thinking, it is only with the ‘H’ of ‘How’ that we move on to action. How can we solve the problem, and especially how has it been addressed in literature? The BIM could be the answer to the first question if we critically analyse the many facets in which it has been presented since its introduction in the early 2000s.

As mentioned for CDEs, the biggest problem of BIM related to research is probably the fragmented treatment, which is unable to contribute to the definition of a best practice. The processes of creating a model can be completely different for new and existing buildings. In the first case, the purpose is to provide a product that is articulated in the different phases of the building lifecycle (ISO 22263:2008-R2022), from inception to demolition. As the implementation of such models is not complete, isolated solutions, designed for a specific purpose, are too often employed. For existing fabrics, depending on the availability of previously developed BIMs, the repository can be updated or re-created. In Italy, structures from the 1970s account for more than 60% of all constructions and they are mainly without documentation in digital format. Therefore, in practice, complex and costly reverse engineering processes are almost always used to retrieve the necessary information.

The panorama previously outlined is therefore very articulated and the complex problems that derive from it can be more extensive. This research is oriented towards a broader dissertation to provide solutions to the issues arising from a fragmented treatment of the topic (BIM, existing BIM, Historical/Heritage BIM). The methodology is interpreted as a system consisting of four interconnected elements:

• functional aspects, which analyse the capabilities or services provided by the BIM in the narrow sense (model construction) or by its accompanying software for data output. The functionalities can be internal (the seven ‘dimensions’) or connected through independent applications. Think of the structural calculation or any operation on specific requirements. This also includes analyses of the accuracy and efficiency of digital reproduction;

• informational aspects and interoperability, which include issues related to the structured organisation of knowledge and data exchange, to ensure interoperability between different software systems without loss of information;

• technical aspects, which refer to the construction of the model and depend on the Level of Development (LOD) relative to the designated functionalities. Some examples are data acquisition, processing, object recognition and modelling. The procedural pipeline can be differentiated between new and existing buildings;

• organisational and legal aspects, which define the general features of the model, the roles of the parties involved, their rights and responsibilities regarding information, their access to the model (reading and writing) or their obligation to provide a defined functionality.

The four elements just introduced are interconnected and can be interpreted as nodes of a graph (leaving out here the presence of some elements external to the system). The arcs that connect them can be grouped into two fundamental paths: the flow of information, which moves from the technical aspects towards the organisational ones, and