3D BIM Explained: The Foundation of a BIM Journey.

Building Information Modelling (BIM) is transitioning from a ‘modern way’ to design, build, and manage construction projects to a ‘compulsory way’ for all projects, big and small. Nowadays, all public-private partnership (PPP) tenders are requiring “some” form of BIM capability and delivery, although the standards and expectations vary from project to project.

If you distil it down to its essence, BIM is an information exchange, communication, and collaborative process. BIM involves using a digital model at all stages of a project – from project concept right through to handover and facilities management.

There are currently 7no. Ds (dimensions) of BIM that are used throughout the life-cycle of a project, but AEC professionals recognise them from 3D BIM onwards. 3D BIM modelling is the foundation of any project that is following the BIM process.

The 3D BIM stage involves the geometric 3D modelling of a project containing a high Level of Detail (LOD) and high Level of Information (LOI). If executed correctly, the digital 3D model will be the foundation of a BIM project and will lead to swifter decision making from a very early concept design stage right through a project lifecycle including important clash detection during the construction phase, or prior to it!

The ultimate goal of 3D BIM is to provide the foundation for a ‘digital twin’ of the ‘As Built’.

Definition: What is 3D BIM?

3D BIM (3-dimensional building information modelling), or a shared informational model, adds an additional “Z-axis” to the existing X and Y-axis. 3D BIM is perhaps, the most well-known dimension of BIM. The international standard for Building Information Modelling ‘ISO 19650:2019’ defines BIM as a ‘Use of a shared digital representation of a built asset to facilitate design, construction and operation processes to form a reliable basis for decisions. It is not about creating a 3D model for its own sake, and it is not an add-on process. BIM is fundamental to the way a project is set up and run.’

3D BIM is the process of creating geometrical and non-geometrical information and sharing this information in a common data environment (CDE). This allows participants to manage their multidisciplinary collaboration more effectively in modelling and analysing complex structural problems. 3D BIM centers around the creation of exchange information requirements (EIR), which defines the information that an employer wishes to procure, develop, and operate a built asset. Establishing this in a contract document ensures that appropriate information is created in a suitable format at the right time.

At BIM level 2 (the most recognised level in the AEC sector), building information models are likely to comprise a series of models prepared by different appointed parties, including model files, documents and structured data files containing non-geometric information about the facility, floors, spaces, systems, and components. Together these create a federated digital replica of the built asset that begins by representing design intent, and then reflects what has been built and installed by handover.

3D modelling forms part of the 7 dimensions of BIM. The BIM dimensions, which refer to the levels of information in each BIM data, are:

3D modelling | geometrical, graphical information.

4D time-related info | construction sequencing by means of Gantt charts and timelines.

5D cost analysis| cost management, construction cost estimating, etc.

6D sustainability| environmental, economic, and social sustainability impact studies.

7D life cycle and maintenance| Facility Management: planning and management of maintenance operations throughout the building’s lifecycle.

All the dimensions rely on a 3D geometry to work. However, it’s the amount of data and information that reside inside the geometry that expand the number of dimensions that all the stakeholders participating in the project can use to conduct studies or analysis on the building in the digital environment.

What Software is used in 3D BIM Modelling

The ISO 19650 standards do not list any official BIM software, but specific software must be identified by design teams in the EIR and the BIM execution plan (BEP). According to the NBS National BIM Report 2017, the most popular BIM software are:

  • Autodesk Revit (Architecture/Structure/MEP) 41%
  • Graphisoft ArchiCAD 15%
  • Autodesk AutoCAD 14%
  • Autodesk AutoCAD LT 12%
  • Nemetscheck Vectorworks 9%
  • Other 4%
  • Bentley Microstation 2%
  • Trimble Sketchup (formerly Google Sketchup) 2%
  • Bentley AECOsim Building Designer 1%

This software is compliant with ISO standard ‘16739-1:2018 Industry Foundation Classes (IFC) for data sharing in the construction and facility management industries — Part 1.’

While all the listed software has the capability of working in a 3D environment, other software such as 3ds Max, Unity, and Blender are more renowned for visualization purposes.

IFC file types are an open international standard for Building Information Model (BIM) data. They are files that allow for the exchange and sharing of digital 3D models between software applications used by the various participants in the construction or facility management industry sector.

The IFC is a format that can guarantee the collaboration between all the parties involved without the interoperability between different software as it will be checked at the start of the BIM process in the BEP. The IFC format is one of the systems for openBIM, the other more renowned formats are BCF, COBie, CityGML,bnXML. These formats are used in BIM projects to ensure the collaboration, and that all the data can be stored into 3D geometries that you can build with a compliant software. While some software providers have a much larger market share than others, they are not the only 3D BIM software available to be compliant with the BIM process.

How is 3D BIM used?

BIM is used across the AEC sector and can significantly improve the delivery and performance of projects while providing a consistent approach that promotes collaboration and innovation. 

BIM processes have helped deliver benefits such as monitoring, safety, planning, cost, and many more. It has the potential to deliver further benefits in the operations of small enterprises by establishing standardisation and asset libraries that can be used across design teams.

3D BIM and 3D Coordination

3D Coordination, also known as Clash Detection, is a process that involves the combination of 3D models from different consultants, usually using Autodesk Naviswork. While Naviswork is not a modelling tool, it can import multiple formats and merging models together in one file called the ‘federated model’.

In this environment all the different models are clashed together to establish if there are problems to solve. As 3D geometries are storing all the data, it is effortless to discover who is the owner of one element that is clashing with another one.

For example, a cylinder representing a pipe may clash with a box representing a machine in a 3D environment. This preventative measure avoids on-site clashes avoiding cost overruns. 3D BIM makes it possible to create detailed clash reports during the design stage. Modern 3D graphics have made the clash detection process streamlined and fool-proof. Architects and designers can now detect clashes during the earliest stages of design. This is reflected in the famous MacLeamy curve; this summarizes in a visual way the benefit of the coordination process in the early stages of a project, when moving a wall or rethinking a pipe system in the 3D digital environment doesn’t cost as much redoing the same work on site after.

The MacLeamy Curve.
The MacLeamy Curve.

In general reworks on site account for up to 34% of total project costs, according to a 2018 study.

3D BIM and 3D Visualization

With BIM and 3D visualisation software, it is easy to quickly create a 3D massing model of the initial design concept and overlay it onto accurate site data. This gives the clients a better understanding of the proposed design and allows any adjustments to be made early on before too much time has been spent on the project.

Through 3D modelling software, Autodesk Revit you can explore a model in the first person and carry out inspections. The model can be shared in the cloud allowing people to explore without any technical background in BIM modelling such as future tenants of a building.

Real time rendering from 3D modelling tools.
Real time rendering from 3D modelling tools.

The Future of 3D Bim

Arguably, the future of 3D BIM is already here; It is now possible to bring intelligent digital 3D models together with reality capture technologies through cloud processing to connect collaborative models with psychical on-site structures.

The combination of 3D BIM and smart technologies such as artificial intelligence is a growing trend in the industry. Using big data and complex algorithms (Using AI) can create standardised design models at a fast pace. The resulting digital models can then be tested on virtual platforms such as BIM 360 OPs to determine viability and cost, the local environment, and the developer’s specific requirements. This means decisions and commitments can be made at an early stage, which speeds up the whole process.

3D BIM can also be integrated with virtual reality (VR) and augmented reality (AR) to provide a standard way of working and perceiving buildings. Houses or whole developments could be hosted in the cloud and people from all around the globe could visit and feel the space from their living room by wearing a VR headset. Real estate professionals are already adopting these technologies which was accelerated by the COVID-19 pandemic. Goldman Sachs estimates that by 2025 the VR market in real estate could be worth £1.99bn and disrupt the way properties are let and sold.

Connecting collaborative models with psychical on-site structures.
Connecting collaborative models with psychical on-site structures.

Conclusion

3D BIM is going to be the focal point for the digitalization of the AEC sector. As outlined, the capability to create an intelligent digital 3D model that stores information, will be used for years to come by all the participants in the process such as architects, engineers, surveyor, and owners to make informed decisions.

New technologies are going to create new opportunities and will result in significant value and return on that investment. Initially, 3D BIM requires time to be implemented and absorbed.

It is also important to note that good input/creation = good output. Making sure that 3D BIM models are created properly (whether in house or through a 3D BIM consultant such as ourselves at 3DDB) will lead to better BIM experiences on projects. Also, selecting the appropriate hardware and software for BIM implementation and allowing for compatibility and interoperability with the rest of the industry are real world challenges to be fully ironed out. That said, we are getting there.

It’s an exciting period for 3D BIM as we change the way to design and build our cities of the future, in the real world AND in the digital world, both of which will continue to become more interconnected.

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