Building Information Modeling has accelerated project delivery, facilitated improved coordination between disciplines and enhanced visualization early on in the design process amongst other benefits. BIM practices and standards are at varying stages of development throughout the world but it is gradually becoming an intrinsic part of the AEC industry especially as the industry moves towards further digitalization. How did BIM come to encompass so much, play such a pivotal role in project delivery and where is it going?
Revisiting the basics
The ISO (International Organization for Standardization) defines BIM as the “Use of a shared digital representation of a built asset to facilitate design, construction and operation processes to form a reliable basis for decisions.” Similar to how Computer Aided Design had been re-invented and tied to particular design tools and software that we are still using today, BIM has been experiencing an epistemological change since its initial emergence in the 1970s. As indicated in this article from Autodesk’s construction blog, as the industry worldwide continues to adopt BIM technologies and ways of working remotely, the concept of BIM is no longer specific. In fact it’s likely that terms like BIM, VDC etc. – which mean different things to different people – will disappear but what they relate to. i.e., enhanced digitalization of information related to design concepts and design details, design coordination, cost, timeline and project delivery become commonplace.
In this article we are leaving out the history of BIM and its scope to wikipedia due to the enormous amount of authoritative literature available. To understand more the essentials of this topic and prospects for the future, we can look at the recent developments in this space and examine some of the questions raised since its implementation. We will examine a few points below intended more to open discussions as opposed to summarize what is still an open field of knowledge.
The Parametrization and Automation of Design
In a nutshell parametrization can be summarized as way of assigning interrelated parameters to various properties of a digital model, take for example a dimension in a structural analysis model, with the aim of facilitating seamless and efficient modifications to models as design changes occur. Parametrization often involves the use of scripts/routines which enforce the change of a property in a model once the related property has been adjusted by the model user. For example the shape/volume of an entire model changes once a single dimension input is changed. This can be extended to various properties such as unit weights, volumes, locations, directions etc.
Information in a mid-level BIM model (refer to 4 levels defined in the UK system) by definition would contain attributes/properties which are input by the model creator. – such as member sizing and section profile, joints types, etc. Once a change is made to any of these properties, the affected properties are automatically updated by the parametric script. Continuing the example above if a model is parametrized to a high degree, once the architect says they want to add another 50ft to the building height, the structural engineer inputs this single height input into their parametric model, which has an established routine/script in place which says for every 10’ we a add a new floor plate. Subsequent scripts enforce that these new floors are analyzed and sized. The script can be extended to reflect these changes in the Revit model and drawings.
This all sounds very efficient and seamless – one or few inputs, we hit the big red BIM button and we have an updated, designed and analyzed structure, through the use of various scripts. The reality is these scripts often need to be very complex, often contain bugs or underlying issues which often are not understood by the users. This black-box cannot be interrogated by users who fail to identify issues or errors as they occur. In the long run this can actually do more harm than good.
Various technologies have made automation and parametrization a reality to some degree, but there is still a way to go to make automation an all encompassing seamless process for designers. Parametrization has certainly added significant benefits and efficiencies to the design process, but it’s important that we don’t loose sight of the level to which we can automate the design process. It seems like part of this may be educating designers about the various automation and parametric tools, so that they understand thoroughly how they work, when to use them and what their limitations are.
The much promoted dimensions beyond 3D in BIM might not seem as exciting as string theory that goes up to 11D. The 4D to 6D (and recently 7D) refers to information concerning schedule, cost, asset management, sustainability, and real world data collected post-construction. BIM is aimed at streamlining the whole lifecycle of a building from project delivery to asset management within one or at least a few platforms. These dimensions are part of the planning, design, building operation and maintenance part of the project. But even these 7D models won’t contain every element of the design – e.g. these models do not, as of yet at least, contain analysis capabilities such as how much additional load go into a structural column if new floors are added to the building – this is a long way off, and may never become part of one single model.
Up to now all these parameters, part of the 6 or 7D model, have not been systematically tracked and digitized in the same platform that can be handed over from designers, to contractors, then to owners. This may begin to happen in earnest with the prevalence of multi-D BIM technology, and when sustainability legislation comes into play (See our article on Sustainable Building Design and Whole Building Design).
This brings to mind a couple of items which are likely to come into sharper focus in the industry very soon. Firstly there will likely be a big shift and concentration towards data collection and incorporation into BIM models. This data will be used to assess how certain designs or processes provide benefits in terms of sustainability, scheduling, cost, constructability etc. It also brings up the topic of legalities around ownership of BIM models, the data and IP they contain. This is a larger topic which merits its own discussion. The below diagram goes some way to describe some of the current dimensions BIM encompasses.
The need for standards
Up to now the level of implementation in BIM technology still varies greatly in different countries. According to ConstructionDive, the US has recently been pushed, through NBIS and participants such as Autodesk, Bently, WSP, HDR, and federal agencies, to formulate a comprehensive US BIM standards for public projects. Compared to the US where BIM standards vary in different states, the UK has led the charge in terms of BIM requirements and legislation along with some other select European and south American countries. These standards will have to develop further as BIM technologies and what it encompasses evolves further.
Another growing element of BIM is the emergence of interactive technologies such as VR/AR technologies, AI technologies along with 3D scanning, new survey technology, and more. You can read about some of these in more detail here. There is huge potential in the forms and fluidity of data (see also the mathematical definitions of topology and mapping) which will change the way we interact with the environment.
In summary BIM encompasses a lot of areas related to information exchange and digitalization within the construction industry. We hope we have given an insightful description of what it is and what it could become. The prospect of what BIM can evolve into highlights challenges but also comes with a great deal of excitement.
We welcome any comments and thoughts! Thanks for reading.