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Dangl.AVA - a SaaS solution for the Construction industry

Providing a modern way to handle the full tendering, invoicing and procurement workflow in construction projects


About the client

The client is a German technology company with a range of digital solutions within the Construction industry. DanglIT GmbH is a pioneer in smart and modern BIM model analysis.

Find out more about DanglIT GmbH on their website:

  • Industry: Construction

  • Location: Germany

About the company

DanglIT GmbH is a Germany-based software product company specializing in Architecture, Engineering & Construction solutions. It provides tools and consulting services around building informatics, specifically in BIM (Building Information Modeling) and tendering workflows, being a great expert in GAEB and its integration into the client’s applications, as well as cloud-based web services for tendering, calculation, invoicing and BIM model analysis & transformation.

Our collaboration

The collaboration we’ve had with DanglIT GmbH is very meaninful and fruitful for us, as we have many things in common when it comes to work ethics, but yet have many to learn from them. It is a great pleasure to work on such a promising product with all the chances of becoming a game-changer in its domain. Our engineers have been working on several products in the Dangl.AVA series, namely Dangl.PfeifferAVA and Dangl.BavariaBim.

Product benefits explained

The product’s primary purpose is the calculation of all materials and the cost of manufacturing the building. Users can add pictures, make estimates, and look for contractors who can perform additional work as cheaply as possible. As a result, they determine what amount is obtained for the manufacturing of the building. Also, it allows to parse and evaluate bills of quantities in seconds, interact with custom built systems for simplified data exchange, optimize the data interface, and realize the industry requirements.

What problem it solves

The German GAEB data format is designed to facilitate exchange in tendering and contracting, mostly aimed at the construction industry. The standard has been around for a while, dating back to a 80 characters-per-line punch card format in the 70s, with it’s most recent iteration just from 2019. It’s a really powerful but also complex schema. Dangl.GAEB is a suite of libraries designed to read, write and transform all known GAEB formats into a single, unified format with full change tracking, ready to be dropped into any application and be immediately usable. It’s rock stable, thanks to over 345.000 unit & integration tests. These are run with multiple different frameworks on every commit, across Windows and Linux operating systems.



Work with parsing IFC files, and Test Driven Development(TDD) because tests cover the entire project.

Working with Electron opened up new possibilities for NodeJS and extended the functionality for Javascript-oriented languages/frameworks (in particular Angular).

Any problem can be solved in 100 different ways. Still, for our developers, the main goal in solving a problem is simplicity (the code should be understandable to another developer), code minimality (minimum variables, use of the modern ES6 approach), reliability (eliminate the possibility of exceptions, testing), universality ( reuse of class methods or functions).

  • Can read all GAEB90, GAEB2000, and GAEB XML files. The GAEB library includes a lot of code that can recover from errors that were found in files out in the wild

  • Hassle-free import: Just pass the Stream of the file to the converter, and format detection and error recovery happens automatically

  • All libraries are available with both .NET Framework and .NET Standard targets, making them usable on virtually all platforms (for example on Windows, Linux, Mac, and Xamarin)

  • Dangl.GAEB provides a native interface to all features of GAEB files, allowing native operation directly on the GAEB file

  • Dangl.AVA offers a unified data model that can be bi-directionally imported or exported via Dangl.AVA.Converter between GAEB, Excel, and JSON

  • Advanced heuristics allow the preservation of most information even when converting to an earlier version of the GAEB standard

  • Complete INotifyPropertyChanged support in Dangl.AVA and event-driven messaging make it directly usable in front-end applications - Set the price of an item and the whole bill of quantity is automatically updated

  • Over 345.000 tests are run automatically on every commit. The tests cover 7 frameworks (both full .Net and .Net Core) and over 200 GAEB files

« QIT was providing services for both front-end and back-end development. The main advantage we saw was that the team from QIT Software was very reliable and had a mastery of modern workflows and programming concepts, both in TypeScript / Angular and .NET Core, where in the latter we not only had an ASP.NET Core microservices architecture but also library projects »

Georg Dangl, Managing Director at DanglIT GmbH

Job done by QIT Software

QIT Software engineers have been working both on the front-end and back-end parts of the project. With the help of Docker, everything can be stored on one computer; it also has a database that does not require installation. We used Microsoft SQL Server and had one-click solutions for database seed generation with test data that mimics real project usage. The back-end contains HTML templates for C#, and these templates were created and styled by us.

Our Engineers have also contributed to the Dangl.AVA calculation module and it’s related projects that can be used for all requirements in tendering, procurement, calculation, and invoicing (German: AVA). The C# .NET package allows users to access a full AVA solution from anywhere – desktop, Cloud, and mobile.

Implemented features

Interface and templates development

The Dangl.AVA module and its interface are used to create a project structure. Users can convert their data to any GAEB format via Dangl.AVA.Converter. All of the GAEB features are accessible this way.

Data export

Most of the work is done with Dangl.AVA, then you can convert data via Dangl.AVA.Converter and supply a custom Plugin for the export process to inject its own logic in the creation of the GAEB data. This gives the best combination of time saved due to the unified project structure while still having full control to customize the export.


Information output in various formats, tables, and one-key data entry (functional “hot” keys).

Hierarchical structure

Tree view development (enables a hierarchical list with expanding and collapsing nodes that contain nested items. It can be used to illustrate a folder structure or nested relationships in your UI).

Visualization of information

Data visualization (data structure is interlinked with the model)

Correct work with data

Preparation of the entered data on the frontend

Work with directives

Directives for rounding values in input fields and the possibility to resize tables.


In the end, we got a product compatible with all platforms. Full GAEB support and ready to use in your application. Whether web, mobile or desktop, Linux, Mac or Windows. Full .Net and .Net Core compatibility.

Currently, this SaaS has almost no competitors in the German market and has great success among real estate investors in Tendering, Procurement, and Invoicing. Clients all over the country can easily integrate AVA products with their systems to become better and more efficient at planning and constructing projects and support the advancements of the OpenBIM standards.

Curious but not convinced?

If you don’t know where to start, we will be happy to guide you with a free estimate for timeline and price.

QIT software