BIM Teaching and Learning Handbook

Implementation for Students and Educators

M. Reza Hosseini, Farzad Khosrowshahi, Ajibade Aibinu, Sepehr Abrishami

• Editorial: Routledge
• Año: 2021
• ISBN:
  9781000418910
• Edición: 1
• Categoría: Arquitectura
• Categoría: Diseño arquitectónico

This book is the essential guide to the pedagogical and industry-inspired considerations that must shape how BIM is taught and learned. It will help academics and professional educators to develop programmes that meet the competences required by professional bodies and prepare both graduates and existing practitioners to advance the industry towards higher efficiency and quality.

To date, systematic efforts to integrate pedagogical considerations into the way BIM is learned and taught remain non-existent. This book lays the foundation for forming a benchmark around which such an effort is made. It offers principles, best practices, and expected outcomes necessary to BIM curriculum and teaching development for construction-related programs across universities and professional training programmes. The aim of the book is to:

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• Highlight BIM skill requirements, threshold concepts, and dimensions for practice;

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• Showcase and introduce tried-and-tested practices and lessons learned in developing BIM-related curricula from leading educators;

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• Recognise and introduce the baseline requirements for BIM education from a pedagogical perspective;

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• Explore the challenges, as well as remedial solutions, pertaining to BIM education at tertiary education;

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• Form a comprehensive point of reference, covering the essential concepts of BIM, for students;

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• Promote and integrate pedagogical consideration into BIM education.

This book is essential reading for anyone involved in BIM education, digital construction, architecture, and engineering, and for professionals looking for guidance on what the industry expects when it comes to BIM competency.

Section 1

For students and trainees

Section 1–1

Foundations and threshold concepts

1 Foundational concepts for BIM

Rafael Sacks and Ergo Pikas

Introduction

BIM (building information modelling) is many things to many people, but the one thing around which there is consensus is that BIM represents a paradigm change for the construction industry. Since civilizations began building things that required the cooperation of more than one individual, people have struggled to conceptualize the structures they were building and to communicate their ideas with other people. Design and construction, which are both individual and collaborative activities, depend entirely on people forming mental models of structures and communicating those models with their collaborators. This began with simple descriptions in language and rudimentary sketches in the sand, and developed into drawings on various forms of papyrus, parchment, stone, and paper. Some of the earliest drawings can be found in Vitruvius’s De architectura (On Architecture), a ten-volume handbook for Roman architects.

Communicating mental models of building structures with anything more than speech essentially began with the consolidation of Euclidean geometry (Booth, 1996), some 2,300 years ago, and did not improve much until the invention of descriptive geometry in the 1760s. In 1799, Gaspard Monge published a book defining a precise method for describing physical objects with three dimensions using arrays of 2D drawings (Monge, 1799). The method, with parallel projection and fixed orthogonal views, was used by generations of architects and engineers and remains deeply rooted in the industry today.

In the late twentieth century, descriptive geometry underpinned the development of computer-aided design and drafting (CAD) software for the construction industry. The only difference was that now, instead of using ink on vellum or mylar films, architects and engineers could draw the same 2D views using a computer. While CAD had numerous advantages, such as automating the menial tasks of drawing repetitive parts, automatic accurate dimensioning, and electronic storage and file transfer, it is no different in concept from drawing with pen and paper.

BIM, then, is the next step in the technological evolution of conceptualization and communication of mental models of buildings and other structures. It is quite different in concept and in practice from its predecessor, descriptive geometry and its 2D drawings. It is a radical change in concept because the primary depiction is multi-dimensional rather than 2D and because models are composed of objects that represent the conceptual parts of buildings, rather than compositions of abstract symbols that require interpretation according to convention. It is a radical change in practice because it offers the industry the first practical means to build and test prototypes before constructing buildings. Figure 1.1 provides an overview of the process in which we model a new building digitally (model the product), simulate its functions (to test its performance), digitally simulate construction (model the process), build the building and monitor and control the construction process, update the model, and subsequently operate and maintain the building, all using BIM. We explain these ideas in the next section of the chapter, “What is BIM?”

Figure 1.1 An overview of a comprehensive BIM process, encompassing virtual design, virtual construction, physical construction, and operation of a building using BIM.

Students who learn the foundational concepts of BIM at the start of their professional training will enjoy an advantage denied their predecessors – the freedom to accept BIM as the standard way of doing things, rather than struggling with it as a disruptive innovation in their professional lives. They will be not be restricted by the need to represent a 3D world in 2D (and indeed, they may explore design and communication with more dimensions, such as time, cost, etc.). This is the subject of the second section, titled “How do we work with BIM?”

The third section outlines some of the practical benefits of BIM from the perspectives of various stakeholders in building and construction processes. Finally, the chapter provides a glossary of the key terms that all students and practitioners must become familiar with; jargon remains an inescapable hallmark of any true profession.¹

After studying this chapter, you should be able to:

• explain what BIM is, covering both process and technology aspects;
• list the principles for working with digital prototypes;
• explain the importance of simulation for evaluating building performance before construction;
• comprehend BIM jargon.

What is BIM?

Building information modelling, or BIM, is a paradigm shift in designing, engineering, constructing, and managing buildings and other infrastructure (Sacks et al., 2018a). It is fundamentally different to the paradigm that has dominated the architecture/engineering/construction (AEC) industry since the Renaissance in three specific ways. BIM platforms:

1. use multi-dimensional (3D, 4D, and so on) representations of buildings;
2. model buildings as compositions of digital objects that are faithful to the form, function, and behaviour of the physical building elements they represent;
3. serve as digital prototypes that enable simulation and analysis of the functional performance of buildings.

With the new capabilities of BIM technology, new design and construction processes have emerged to exploit these capabilities to the full. Thus, BIM encompasses both computer technologies and business processes. Four key characteristics distinguish BIM technologies and BIM processes:

1. They offer object-oriented representation of form, function, and behaviour.
2. They have the ability to build and test digital prototypes of buildings.
3. They allow for the integration of the work of all the people involved in a construction project.
4. They provide an information environment and is an enabler of “construction tech”.

Object-oriented representation

In much the same way that buildings themselves are composed of physical elements, such as walls, doors, windows, beams, and columns, BIM models are composed of digital objects. However, the objects in BIM models can also represent abstract concepts that have no material manifestation, such as rooms or systems. Architects, engineers, and construction managers think of buildings in terms of functional systems as well as in terms of physical components, and it is these conceptualizations that give BIM models an additional layer of useful information. They include aggregations of physical elements and volumes bounded by physical elements. All of these, whether physical or abstract, are objects. All BIM modelling software tools use object-oriented programming. This means that each object has associated software modules – called methods – that implement the function, the form, and the behaviour of the objects.

Function refers to the design purpose intended for the objects, that is, what the object(s) are expected to do. For example, a door provides access from one space to another; a concrete slab is designed to carry live loads imposed on a floor to the beams, walls, or columns that support it; walls enclose spaces, which are designed to fulfil specific functions as rooms – bedrooms, kitchens, bathrooms, etc. Functions can also be modelled as relationships between objects, such as “object A supports object B”, or “object C encloses object D”. In general, an object’s function is represented explicitly by its class within the BIM system (e.g., a “Wall” object) and/or by alphanumeric values assigned to its object’s properties (its attributes).

Form refers to the geometry of physical objects, and it is always represented using solid geometry. There are two ways to model solid geometry – with boundary representation (B-rep) or constructive solid geometry (CSG). In B-rep, sets of faces define volumes with closed manifolds. In CSG, basic parametric volumetric shapes are combined using Boolean operations. CSG solids are parametric and thus easier to edit than B-rep solids. One can generate B-rep forms from CSG formulations automatically, but deriving a CSG from a B-rep is difficult. As such, CSG forms are preferred.

Behaviour refers to the way in which objects are created and adapt parametrically to their context. For example, a window can only be placed in a wall; if the wall is made thicker, the window frame must adapt automatically; if the wall is deleted, the window must “delete itself” too. Behaviour is implemented using parametric constraints and relationships. An equivalence relationship of the window frame’s thickness parameter to the wall’s width parameter allows a software function of the window object to reset the window’s geometry when the wall’s geometry is changed. These relationships can include constraints that enforce minimum distances between objects, parallel or perpendicular orientations, coincidence of points, etc. Figure 1.2 illustrates an example of a dimensional constraint.

Figure 1.2 A dimensional constraint applied to fix the distance of a window from the corner of a room. The closed padlock symbol below the dimension indicates that if the left-hand wall were moved to the left or right, the window would move accordingly to maintain the 1,000 mm distance.

Object-oriented modelling also gives BIM software objects properties of encapsulation, data abstraction, polymorphism, instantiation, and inheritance. While these terms have specific meanings for software programmers, they also lead to behaviours in BIM systems that users of BIM software should be aware of. Encapsulation means that the software functions which implement an object’s behaviour (its methods) are intrinsic to that object’s class and the object’s properties and the details of its methods are hidden from calling functions. Thus, the same external command in a BIM system may cause different behaviours in different objec...