Digital transformation: Smart building with BIM

1.  What is BIM – and how does it work?

Building Information Modelling (BIM) is a collaborative working method that enables experts to create a multidimensional virtual image – the so-called digital twin – of a building or infrastructure project during each phase of the entire construction project, which contains all relevant physical and functional properties. This creates a shared, centrally managed project data pool with interrelated specialised models that all parties involved – such as architects, engineers or contractors – can access, thereby improving fine-tuning and planning accuracy. Traditional documentation such as drawings or tables can therefore be dispensed with.  

As part of the so-called collision check by integrating various specialised models (e.g. architecture, statics, building services), potential conflicts, such as overlaps between pipes and structural components, can be identified and resolved as early as the planning phase. Linking the 3D model with schedules (4D) and cost information (5D) supports effective project management by allowing construction processes to be simulated and optimised and cost forecasts to be created more accurately. During construction, BIM serves as a central source of information that documents construction progress and enables the exchange of up-to-date data between the construction site and the office. This leads to greater efficiency and quality assurance. Once the building has been completed, the BIM model provides valuable information for operation and maintenance. Facility managers can access detailed data on materials, technical equipment and maintenance intervals in order to optimise the management of the building. 

2. Pipeline construction: BIM could be used in a standardised way

According to the Technisches Positionspapier published in 2020 by the Deutsche Gesellschaft für grabenloses Bauen e. V. and the Rohrleitungsbauverband e. V. in collaboration with the Bundesfachabteilung Leitungsbau im Hauptverband der Deutschen Bauindustrie e. V., the use of Building Information Modelling (BIM) is currently being considered primarily in the context of planning and approval. Digital building information models open up significantly more far-reaching possibilities – in particular through the continuous use of existing project data, regardless of the project status. In pipeline construction in particular, numerous processes could be designed more efficiently and BIM could be used in a standardised manner in different project phases. Chapter 4 of the position paper, the core statements of which are summarised below, shows how BIM can be introduced in pipeline construction in a step-by-step and practice-oriented manner: 

• Consistent use of structured data 
  A key success factor is the seamless transfer of planning and construction data along the value chain. BIM not only enables higher quality in planning, but also concrete added value in tendering, construction and operation. 

• Standardisation of object catalogues 
  A standardised object catalogue with clear classifications and features is essential in order to consistently link model content with specifications. The aim is a consistent information structure from planning to operation. Standardised formats such as Industry Foundation Classes (IFC) form the basis for this.  

• Revision of regulations 
  Existing regulations - for example from procurement, contract or budget law – must be adapted in line with BIM. Standardised framework conditions should eliminate uncertainties in use.  

• Use of open data formats and common data environments (CDE) 
  Open formats such as Industry Foundation Classes (IFC) and powerful CDEs are a prerequisite for effective exchange between all project participants. Proprietary formats such as Construction Process Integration (CPIXML) can also be used temporarily.  

• AIA + BAP as a „BIM building specification“ 
  The combination of client information requirements (AIA) and the BIM execution plan (BAP) forms the basis of every BIM application. The AIA defines what information must be provided when and in what quality; the BAP describes the implementation in detail, including roles, processes and technologies.  

• Software requirements 
  The software used must fulfil the complex requirements of pipeline construction, including large length extensions, integration of GIS data (geodata, digitally recorded and stored), soil and groundwater models as well as detailed logistics and construction process representations. Compatibility with existing systems and standards is also important. 

It is emphasised that even the partial use of structured digital data brings significant benefits - for example through more efficient processes, error reduction and improved collaboration between all parties involved. 

Advantage in practice: Integration of laser scanning in BIM models  
A combination of terrestrial and airborne laser scanners with a BIM software model has proven to be particularly advantageous in the construction of gas plants and pipelines in order to optimise planning, production and documentation processes. According to Bohlen & Doyen Bau GmbH, a full-service provider in the field of energy infrastructure construction, the point clouds generated in this way can serve as the basis for creating three-dimensional objects, among other things. 

 „Laser scanning devices generate point clouds with both extreme density and high absolute accuracy, and both at very high speed [...]. The resulting point clouds can be excellently combined at the end and offer the possibility of storing both overviews and detailed recordings in a database“, says Bohlen & Doyen. „One of the first applications in the construction process at Bohlen & Doyen was the use of a terrestrial laser scanner for the preservation of evidence of roads and buildings. Within two days, a stretch of road totalling 6 km in length could be scanned with high precision. The scan data was stored and could be used to track damage to the road surface in critical cases after completion of the construction work [...].“ 

According to Bohlen & Doyen, the scans offer such a high resolution that even tiny hairline cracks in road surfaces can be clearly identified. Even minimal changes in the inclination of surfaces, such as subsidence, can be detected by a before-and-after comparison. In contrast to traditional photo documentation, not all images need to be „processed, elaborated or labelled“. It is sufficient to save the point clouds, as georeferencing enables a specific area within a point cloud to be located quickly and linked to the time of recording. In this way, different measurement events can be compared with each other via „a graphically clear 3D difference image“. 

3. Water management: BIM use in practice

The Building Information Modelling method is also becoming increasingly important in water management as part of the planning, execution and management of water management facilities – especially in combination with other data systems. 

GIS-BIM data integration at district water supplier Bodensee-Wasserversorgung 
„The integration of geographic information systems (GIS) and building information modelling (BIM) is an important step towards the optimal use of spatial data in the planning and execution of construction projects“, says the Deutscher Verein des Gas- und Wasserfaches (DVGW), explaining a practical use case of the district water supplier Bodensee-Wasserversorgung. „The integration of GIS and BIM enables not only the precise visualisation of geometric and logical data of a structure, but also the enrichment of the digital twin with specialist data from the GIS. This integration allows spatial relationships and geographical features to be included in the planning and execution of construction projects, resulting in a more comprehensive and accurate visualisation of the building. The combination of BIM and GIS thus enables a holistic view of the building and places it in the context of its surroundings.“ 

In a pilot project, Bodensee-Wasserversorgung has shown how data from mapping programmes (GIS) and digital building models (BIM) can be successfully merged. The FME software was used, which can automatically convert and combine data from different sources.  

An important step was to convert parcel boundaries, which are actually only available as simple lines on maps, into 3D shapes using a terrain model. These 3D surfaces were then incorporated into a digital building model so that it is possible, for example, to check exactly whether planned pipelines meet a property. The data was saved in an IFC file in which each parcel is represented as a floor. This makes it easy to show or hide them and assign them clearly. In future, even more data, such as nature or water protection areas, will be automatically integrated with the aim of saving time, reducing the error rate and optimising planning. 

In September 2022, the first part of the multi-part DVGW set of rules „W 1070-1“ was published, which deals with the basics of BIM in water management. This set of rules serves as a guide for companies that want to plan and implement BIM projects. It offers recommendations for requirements planning, the definition of client information requirements (AIA) and the selection of specialists for BIM coordination and management. 

4.  Conclusion and outlook

In summary, it can be said that Building Information Modelling (BIM) is a transparent, fast and efficient way to map and optimise the entire life cycle of a building with the help of a digital twin.  

The integration of different techniques/specialist models can even increase planning accuracy and efficiency, as is the case when combining BIM with laser scanning technologies, for example. The progressive implementation of BIM requires standardised data formats and the adaptation of existing regulations. The „BIM-Portal – Digitale Werkzeuge und Methoden für die Bauwelt“ offers support.  

A German digital ministry has also been under consideration for some time. This could now become a reality with the new federal government.  

A Ministry for Digital Affairs could play a central role in digitalisation in the construction industry by developing and implementing nationwide strategies. For example, it could ensure that methods such as Building Information Modelling (BIM) are used across the board. The digital handling of planning and approval procedures, for example through online portals for building applications, would also speed up processes and make them more transparent. Another area of responsibility would be the development of centralised digital data platforms, such as a gigabit land register, to support the expansion of digital infrastructure.  

In addition, the ministry could initiate and coordinate research projects on new digital technologies in the construction industry. Equally important would be the training and further education of skilled workers in order to strengthen the expertise of authorities and construction companies in dealing with digital processes. In this way, the digitalisation of the construction industry would be promoted in a targeted manner and contribute to the modernisation and increased efficiency of the sector.