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Recap from the BCF Hackathon in Helsinki and Formation of the CDE Group

Sun, 19 May 2019 10:29:31 Z

This past week, the BCF implementers group came together at the Solibri HQ in Helsinki, Finland, for their bi-annually Hackathon. Besides the regular conference calls, this is a great time to discuss all things related to the BIM Collaboration Format, a standard that should make it easier for users to collaborate on planning & building construction projects across teams. It's solving a key issue in the whole BIM process - the integration of various professionals and tools, often across companies and disciplines.

Photo © Oliver Günter, from left to right: Georg Dangl, Oliver Günter, Pieter Buts, Josephus Meulenkamp, Andrea Dallera, Eduard Mrazek, Pasi Paasiala, Henning Kongsgård, Jari Juntunen, Kristof Kerekes, Veni Lillkåll, Simon Daum, Nick Tindall, Rahul Sule

Past & Future of BCF

BCF currently stands at version 2.1, and it's available both as a file-based standard as well as an Http REST API specification. It's quite stable now and feedback from production shows little problems, except some minor issues every now and then.

Support by applications is steadily increasing, but still mostly focused on the file based Xml exchange format. One of the big goals of the group is to support implementations of an API-based workflow. While there are many options already on the server side, there are still way too few client applications available that use the BCF REST API. For this year, at least, the open source tool BCFier is planned to get some BCF API features implemented.

Another point is to get more end users involved. The BCF Group has always been a very technical group, and most of the standardization efforts were driven by software vendors. This caused long feedback cycles between the group and end users. Now that the standard is more stable, we're actively trying to include more designers, contractors and users into the decision processes. Starting with regional buildingSMART clusters, we're always open to any new members or input.

Formation of the CDE Group

Something that's been discussed lately is the formation of a group that focuses on standardizing APIs meant for Common Data Environments. Similar to what's being done with BCF, successfully utilizing a CDE in construction projects requires that the users - designers, contractors, stakeholders - are able to integrate their own tools in the collaborative workflow.

Common Data Environments are mostly cloud based applications that aggregate and manage data from various sources. Simply said, they're tools that support all or most digital aspects of the construction process in one central place. For this to work, it needs to integrate with existing workflows and applications.

The very basic roadmap for this group is as follows:

The standard for authenticating API requests, part of the BCF API, will be extracted and made its own specification
A basic API for managing documents between applications and CDEs
Further down, some kind of directory service is needed, to discover projects, manage users and roles across systems
In the long term, this group might also extend the web based APIs to support object and attribute level access in the context of digital building models (BIM)

The decision to form the group was made by Catenda, Graphisoft, Oracle Aconex, Solibri and think project! at or before the Hackathon in Helsinki. It will be part of the Technical Room at buildingSMART International Standards Program, and there have been already some early discussions about the document management part, published on GitHub.

Integrating BIM & IFC References with Bills of Quantities and GAEB Files

Wed, 16 Jan 2019 20:09:49 Z

The creation of fully integrated and connected representations of construction projects with Building Information Modelling (BIM) is becoming ever more important. One key point of BIM is that data should no longer be split into individual, separate data islands but that everything should be connected. This leads to real, measurable benefits by avoiding duplication, transfer errors and a much better understanding of the building that's designed and operated.

The BIM process relies greatly on open data formats and a solid, technological foundation in data exchange. Unfortunately, we're still in very early stages of this, so there are many problems in today's industry when different applications talk to each other. At DanglIT, we're tackling this by providing individual software and finished products to deal with that. One of our specialties is the German GAEB data standard, which is a container format used to describe bills of quantities. For building models, the Industry Foundation Classes (IFC) files are often used to represent buildings in an open and well known data format.

Many of our customers ask about connecting these GAEB files with the actual building models. To showcase this with a practical example, let's say you've got multiple concrete walls in a building. Often, these walls are represented by different positions in the bill of quantities. An outer wall can be represented as Concrete, Casing and Reinforcing Steel. On the other hand, you will often only have a single position for all the concrete in all the walls in a project, so there's a mismatch between the data in the building model and the data in the bill of quantities - but both represent the same, real entity!

Linking such cost elements between GAEB and IFC is actually quite easy, and already fully supported with our GAEB & AVA .Net Libraries and SaaS offering. In GAEB, there's the concept of CatalogueReferences, which are typically used to reference some kind of classification but can also hold user defined data. In the example below, the GAEB file (click here to download) defines a custom catalog that references the IFC file which contains the building model:

Now, a single position element in the GAEB file can reference this catalog. The example below contains all the concrete for the project, but a Quantity Split links a sub quantity of 10 m³ to an element in the building model with the Id 04BUoi9FT31BWlyfND2MS2 (yes, that's how IfcGuids look!):

For reference, you can view the full GAEB XML file directly in the browser.

Such simple connections between GAEB and IFC give you real value. For example, here's a super simple web app we've put together - you can load the building model and the GAEB file to visualize the connections between them:

To create the GAEB XML file above with our GAEB & AVA .Net Libraries, here's some example code you can use. That's the complete code actually - you don't need a single line of code more than what is shown to produce the output.

If you have any questions about working with GAEB, IFC, BIM or other, related technologies we're always happy to help. Just contact us!

Oh, and there's one big bonus to this approach: The next version 3.3 of the GAEB XML standard is scheduled to be published by the second half of 2019. Among the new features is a native support for connecting IFC with GAEB. It's going to be working in basically the same way as the example shown above.

Happy Connecting!

Creating GAEB Files with the Dangl.AVA & Dangl.GAEB API

Mon, 31 Dec 2018 13:53:31 Z

Disclaimer: This is a cross-post from my professional website. It's a tutorial for a product my company sells.

The Dangl.AVA & Dangl.GAEB libraries allow you to work easily and fast with GAEB data files. The core functionality of these libraries is to offer import and export features.

Often, our customers do have an existing data structure, for example in their content management system. For such use cases, the GAEB & AVA .Net Libraries are ideal to convert from your own, internal data structure to GAEB.

Different Ways to Export Data

There are three main ways how you can export GAEB data:

You're using the Dangl.AVA module and its interface to create a project structure. Then, you convert to any GAEB format via Dangl.AVA.Converter. Most of the GAEB features are accessible this way. The following examples will focus on this procedure.
With Dangl.GAEB, it's possible to work natively with the GAEB data formats in .Net. You have full control over all details and decide how exactly the GAEB file should look.
You combine both methods. You do most of the work with Dangl.AVA, then convert via Dangl.AVA.Converter and supply a custom Plugin for the export process to inject your own logic in the creation of the GAEB data. This gives you the best combination of time-saved due to the unified project structure while still having full control to customize the export.

The Data Export in Detail

The following two code snippets are based on the sample projects (download) and will show you how fast and easy it is to create GAEB data via the API. The examples are written in C#.

The TutorialFileGenerator class shows you how to export a Dangl.AVA.Project to all three major GAEB formats and then saves them to disk as System.IO.Stream.

In the second part, the actual generation of the data structure in the form of a Dangl.AVA.Project is demonstrated. You will see how easy it is to map your internal structure to GAEB.

Do you have any additional questions? You can find further information and API examples in the documentation. Additionally, customers with a maintenance subscription have full insight into the source code. You find a lot of interesting examples in the test projects.

What is BIM?

Sun, 11 Mar 2018 23:31:34 Z

Disclaimer: This is a cross-post from my professional website.

You have heard about BIM - Building Information Modelling. But you are unsure about what it is exactly. You might have some idea of it, and have possible heard some definitions and explanations before.

BIM is 3D modelling. BIM is modern CAD. BIM is automated validation & checking. BIM is easy data sharing. That's the essence of what you usually hear. All of these are true, but what does it actually mean?

Back to the Roots

There's a saying in Germany: You don't see the woods for the trees. It means that sometimes, getting lost in details makes you miss the whole. So let's focus on that. Without trying to sound tautologic, BIM is simply the modelling of building information.

In traditional design processes, there are a lot of small, independent parts. Be it plans, overviews and sections, but also parts lists, bills of quantities, issue boards or customer requests. There's also such things as minutes from meetings and even rental contracts and maintenance logs.

All of these parts are isolated, often without or with very little relation to each other. Also, a lot of these would not even be considered core information but only supplemental documents. So right now, you don't plan a single building but a lot of small details. You plan a facade, then you plan a floor. You define some interface points, but then you change the facade and don't consider the information that you've written down six weeks ago in the meeting with the customer. You also now have made changes in one place and probably missed at least one other document you should also have changed. Wherever you have duplicated data, there's a lot of potential for conflicts.

That's where the spirit of BIM comes into play: Everything is part of the building model and, by extension, describes a truth or a fact about the (future) building. Together, all small parts form one coherent idea. PDF drawings and door lists are just two different views on the complete data.

This means BIM is not a single method or a specific software, it's the combination of all available data to a true, digital model of the building. You do model the building itself and then generate views of it instead of the other way round. When talking about BIM, this encompasses both the tools (like CAD applications) as well as the processes (consolidation of data in a single, canonical model).

In practice, going full BIM does require a bit of effort and a shift in habits. There's new things to learn, after all. But those who have already done it overwhelmingly realized that it is worthwhile to them and their business.

A Small Example

Let's imagine a project developer standing on a green field. She's got the idea to build a new office complex, right here. BIM starts at this moment. The model is only an idea in someones head at the moment, and in a very early stage. But nonetheless, it's going to grow over time. These first thoughts will form the base for future decisions. Soon, the first drafts are created and shared.

Further professionals join the process - architects, engineers, later contractors and finally tenants.

The idea of BIM says, data is always in the context of a model. That's why modern companies have BIM Managers, specialists who coordinate and manage the flow of data and their processes. They ensure no knowledge is lost or duplicated.

Modern Methods & Tools

Software for the AEC industry (Architecture, Engineering & Construction) is more and more focused on interoperability. This means, tools from different vendors, across disciplines, are able to share data.

Standards like GAEB, BCF and IFC offer numerous possibilities for efficient data exchange and even cooperation on the same model. In the BCF specification group, we made a short clip that demonstrates how modern workflows are done with the latest technologies:

Change in Process

Traditionally, the most resource intensive tasks in a design process happen in a very late stage. The detailed design phase is where most of the planning happens, even though at this stage, a lot of hard-to-change decisions have already been made.

In Germany, this is even more negatively enforced by the HOAI (Fee Structure for Architects & Engineers, German: Honorarordnung für Architekten & Ingenieure). This mandatory regulation structures construction projects in phases, with each phase having a defined work to be done and a percentage of the total project sum that can be billed for it. Since there have been no major changes to it in the last decades, it presents now an enormous hurdle for architects & engineers that want to adopt BIM. Especially in contrast to neighboring countries, German professionals have a huge disadvantage due to the lack of BIM proficiency and a huge discouragement to adopt BIM due to outdated regulation.

To visualize the differences in work schedules, Patrick MacLeamy, CEO of the US-based HOK Architects, defined a small diagram:

At first glance, the difference in when the most work is done is obvious. With BIM, the workload shifts to comparatively earlier stages of the process, when changes can still be done easily and at small costs. While not even BIM can guarantee error-free workflows, the amount of costs incurred due to late changes and undetected errors is drastically reduced. Companies that are already successfully using BIM report savings of more than 50% in regards to error- and failure induced costs.

What are my Advantages?

Many end users are unsure how they can personally profit from BIM. Maybe this is just a trend that goes away and you can skip the time to learn something new? After all, you still get work done today - most buildings get built, eventually.

That's right, but when being honest, one has to admit that the construction industry has been lagging behind all other industries in the last decades when it comes to productivity gains. While branches such as mechanical engineering and software development make huge leaps each year, construction companies are still operating at the efficiency of 1995 (in 2017). Possibilities of the digitalization, the new industrial revolution, have been neglected. But this is changing now with increasing pace.

There are, of course, many more positive examples for BIM. One of them, automatizing labor intensive work, is very obvious. Especially when it comes to data extraction, tools can do in seconds what would have taken humans days. Additionally, data is more and more linked with other data. For example, it's now becoming standard to link GAEB files with the actual building geometry and never again miss a change.

Happy BIMing!