Native OpenBIM, and the rise of open source in AEC

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Article #5 of 8 from AEC Magazine’s IFC Special Report

OpenBIM can deliver on the promise of a digital world for the built environment where information and data are truly valued, writes Dion Moult, emerging digital engineering manager at Lendlease

Believe it or not, our current digital collaboration is relatively primitive. It is as if we are collaborating by exchanging spreadsheets, but every stakeholder is using a different spreadsheet template. Even worse than spreadsheets, in fact – because while anyone can access a spreadsheet, our data is typically locked in a proprietary format.

Spreadsheets don’t expire, but models authored in older software versions cannot be opened or may lose data with current software. Spreadsheets don’t require subscription fees, but most BIM users merely rent their data. Spreadsheet formatting is controllable, but we have limited visibility over how our data is structured.

In short, we have very little control over the data we produce and manage.

However, over the past year, there has been a significant increase in interest in OpenBIM and open source – two distinct but complementary concepts. OpenBIM provides the freedom of our data to be vendor-agnostic and structured in a standardised manner using open standards like IFC. Open source, meanwhile, gives users the freedom to learn, share, and customise vendor offerings to suit their needs. The common thread that links the two is the handing back of control to users.

A digital language

IFC is the only data specification available today that integrates all the disciplines in our industry as a single, cohesive digital language. IFC can describe elements as diverse as: 2D annotations, complex 3D forms, textures and materials, project libraries, structural analysis, MEP system connectivity, civil infrastructure, welding details, construction sequencing, cost scheduling, light and photometric data, space boundaries for energy simulation, environmental impact data, risk assessments, parametric constraints for code compliance, facility management data, document registers, asset maintenance schedules, purchase order tracking, smart building sensor events, device procedures, and time series data. (see article IFC: what is it and why is it needed?)

Today, virtually all software in our industry has at least partial IFC support. Governments and building owners are now demanding higher quality IFC data. IFC support by software vendors is also growing in response.


The interoperability bottleneck

Despite the vast capabilities of IFC, its implementation within software is hit and miss. The limitations and complex workflows to translate the data using export and import leads to huge frustrations. The outcome of which is that users are only exposed to a small fraction of IFC’s capabilities and users believe that IFC is dumb geometrical model, which is the equivalent of a PDF, but IFC has so much more about it and is fundamental when it comes to managing data.

This is not just a technology issue but more importantly a people issue. Culturally, our industry has adopted a ‘software first’ approach. Our digital workflows, contracts and academia are constantly reinforcing our workforce to revolve around software. We need to change into a data-centric culture and invest in digital literacy.

If we want meaningful digital collaboration, we need to put the data first and look at alternatives to historic proprietary data, replacing our foundations with open data standards as a native language throughout the life of what we build.

Open source freedom

When software controls users, the software is traditionally known as proprietary software. When users control the software, the software is given a special name: open source. Sometimes, it is also called free software; this is not referring to price, but to the freedom it provides to users. There are four specific freedoms, enforced by licences:

  1. Users have the freedom to use the software for any purpose, without restrictions from the software licence.
  2. Users have the freedom to study how the software works. The code is available with the guides on how it is built. This fosters cooperation between academia and industry and encourages the growth of technical specialists.
  3. Users have the freedom to change the software to suit their needs. This puts our industry back in control to design the capabilities for our future cities.
  4. Users have the freedom to redistribute the software with any changes. This helps even out inequalities in technology adoption across our industry. If one person across ten companies each make one improvement to the tool, then the industry benefits from ten improvements.

As coding becomes a basic skill taught to all, this freedom will become the norm. The software industry has already made this change – the internet, security, software development, and more already rely on open source and open data standards. Open source in AEC is just getting started!

One of the earliest related developments was in geographic information systems (GISs). In 1984, the GRASS GIS project was created as a solution to non-communicating commercial tools, much like the proprietary BIM problem we are facing today. This project paved the way in interoperability, creating the term OpenGIS, and leading to the formation of the OpenGIS Foundation. Nowadays, this is known as the Open Geospatial Consortium (OGC), and it has helped develop many of the open data standards that are fundamental to the GIS industry. Modern projects like OpenStreetMaps help provide OpenGIS data to over 7 million users.

FreeCAD offers parametric solid modelling, similar to Autodesk Fusion 360 or DS Solidworks. FreeCAD is used for the design of the OpenSourceEcology Seed Eco-Home2 (inset picture)

More recently, Blender has provided mesh modelling, computational design, and CG visualisation to the masses. FreeCAD is doing the same for parametric solid modelling, industrial design, and computer-aided manufacturing. OpenSourceEcology has provided open hardware designs for the built environment, including the latest Seed Eco-Home 2, an open-source, sustainable, modular design for a 1,000-square foot house that you can build for only US$50,000 in one week with a friend.

Making native OpenBIM accessible

Bringing together OpenBIM standards and open source software, we can start to put data first and expose the full functionality of the IFC schema. Open-source software like IfcOpenShell, xBIM and IFC.js are platforms for the development of native IFC tools. These open data platforms have helped start-ups develop new products for our industry. Increasingly adopted in academia for OpenBIM research and teaching, they offer the most advanced OpenBIM capabilities in the market. With these, IFC is no longer a static snapshot. Models can continue to be manipulated using simple scripts freely accessible to all.

IFC models can now be authored and edited for free – this is game changing for the industry!

For users without programming experience open-source, off-the-shelf software like the BlenderBIM add-on – initially started as an experiment at Australian multinational construction, property and infrastructure company Lendlease – has demonstrated that it is possible to natively author IFC from scratch with a graphical interface.

Multiple disciplines can create models directly in a single IFC database without importing or exporting. Blender can be used to access the entirety of IFC’s capabilities with no data loss. The user experience of authoring IFC directly does not need to be complex, or dissimilar to existing BIM tools with which we are already familiar.

IFC models can now be authored and edited for free – this is game changing for the industry!

IFC.js showing a dense rebar model at 60 frames per second on a regular web browser. IFC.js is unique in that it allows you to process BIM servers on the web without the need to run a web server

A combination of open data and open source means that all the systems used to design, build, operate, audit, analyse and prototype our built environment can be made accessible to everyone, from leading design and construction companies to smaller firms, single practitioners, non-profit organisations, hobbyists and concerned citizens.

Open source is not just a software licence. Open source is a culture that promotes users to be in control. The Open Source Architecture community or OSArch is an umbrella society born from the congregation of existing open-source users and developers in the Blender, FreeCAD, and OpenBIM communities. Despite the name, it covers all disciplines. Over 100 open-source software systems are being documented, a world of new technologies is ready to emerge. This is true collaboration born out of a similar passion to improve interoperability, accessibility and quality of data.

Two years ago, viewing IFC data on Linux would be complex, writing scripts to manipulate data would be complex, and native IFC authoring was unheard of. Now, IFC can run locally on any browser. IFCs are editable, disciplines are parametrically merging datasets, and users are starting to question the quality of data outside their silos. This is the result of the volunteer efforts of dedicated individuals investing in open standards and open source: learning together, writing code, agreeing to standards, teaching others, and publishing research. By all of us – vendors, developers and users – working together, we can build a new digital built environment where we truly value information and data.

Acknowledgement: with contributions from Emma Hooper, associate director and head of R&D at Bond Bryan Digital







OSArch community

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This article is part of AEC Magazine’s

IFC Special Report – Enabling interoperability in the AEC industry.

To read the other articles in this report click on the links below.


Industry convergence
From sustainability to new business models, and from wellness to emerging technologies, IFC can be a force for good, driving the AEC industry to new levels of achievement

Inside buildingSMART
What is buildingSMART and what can it offer industry practitioners?

IFC: what is it and why is it needed
Emma Hooper, Associate Director and Head of R&D at Bond Bryan Digital, provides a useful overview of the IFC data model specification

IFC for Infrastructure
Perhaps the most significant update to the IFC standard is the inclusion of extensions for infrastructure entities in IFC 4.3

IFC at Hinkley Point C
By Tim Davies, digital engineering manager, BYLOR JV – Hinkley Point C

Tackling the Gen Zero Project
The UK Department for Education’s Gen Zero project showcases how IFC can be used as the underlying data standard for a large, complex project, from start to finish

buildingSMART certification
By Phil Read, program lead at bSUKI and managing director, Man and Machine


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