BIM in Straßenbau, Hoch- und Tiefbau

Introduction to BIM

BIM stands for Building Information Modeling, which is a comprehensive approach to the entire project realization process in the construction industry. Although the term has been around for several decades, BIM as it is known today is a relatively new addition to the construction industry. Some might argue that BIM, as a whole, represents one of the most significant changes that the construction industry has undergone in quite some time. This is especially noteworthy considering that the construction industry is known for its conservatism and has been one of the last industries in the world to embrace widespread digitalization.

BIM still has its share of rumors and incorrect facts associated with it. One of the most significant misconceptions is the belief that «BIM is just a model,» which is far from accurate. While a BIM model is crucial to the overall BIM approach, the collaboration and transparency between different participants are much more critical for BIM to be effective. Although having a BIM model as a centralized unified data source is helpful, it is not the entirety of BIM.

BIM has the potential to improve various parameters in construction projects, including creation time and budget constraints, while also reducing reworks, eliminating disputes, and minimizing material waste. It can enhance overall project efficiency, increase transparency for all involved parties, and accomplish much more.

Moreover, there are several nuances and specific details about how BIM works in different construction industries. This article will focus on three examples: road construction, high-rise building construction, and sub-surface construction.

BIM in Straßenbau

Road construction projects that use the overall BIM methodology share many general BIM benefits that apply to this specific sphere. The impact of BIM on road construction extends from the early design stages to the facility management phase. This includes advantages such as early design calculations, detailed visualization, work preparation, improvements in logistics, resource planning, accounting, defect management, and more. BIM can also significantly improve the post-handover part of a project, with the complete BIM model being a great addition to tasks such as modification, maintenance, and even eventual disassembly or replacement.

Moreover, there are benefits that are specific to the road construction process. For example, the usage of geographic information systems can provide additional information for BIM. Although it can also be used in other construction types, its implementation in the BIM road construction field allows for better planning and visualization of every project in the context of existing environments, such as other roads or buildings.

Additionally, the Federal Ministry for Digital Affairs and Transport (BMDV) has mandated BIM for federal road construction starting in 2025, in addition to railroads that are already built with BIM on a government level. The BMDV has defined three main goals for trunk road creation with this statement:

• Better sustainability

Recycling and material reuse have become increasingly prevalent topics, especially in the construction industry, which has always been known for producing a lot of waste, whether due to on-site reworks or the general construction methodology. One of the significant challenges in this regard has been that every construction site is viewed as an individual issue from a sustainability standpoint. However, BIM allows for a more sophisticated approach to this issue by answering questions such as «What parts of a building could be recycled?» and «Can any of these parts be reused in the future?» on a large scale. BIM utilizes information from existing and past projects to plan further into the future with fewer reworks and more material utilization/reuse.

• Better communication

Communication issues are often cited as one of the major causes of misunderstandings between project participants and subsequent delays. Therefore, the ability of the BIM method to simplify communication and make it more transparent within projects is one of the most significant advantages of BIM. The detailed visualization and the existence of a single information source for all project participants also make it easier to resolve conflicts and miscommunications.

• Better efficiency

Stability is a crucial aspect of any sophisticated process, including construction. The ability to accurately predict the outcomes of every project phase, knowing that all potential errors and clashes have been identified and fixed during the design phase, gives companies more freedom in long-term planning and more credibility as they complete projects on time and without delays or budget overruns.

The government’s recognition of BIM at the national level is a significant step toward popularizing the method in the road construction industry. Moreover, reports on country-wide congestion are severe, and with the construction industry being among the top three reasons for congestion, it is evident how the government aims to address two issues simultaneously.

BIM in Hochbau

BIM is essential for high-rise buildings, where every project involves multiple levels, and the overall complexity is astounding. While it is possible to perform partial BIM integration during the high-rise building creation process, it is always recommended to begin using BIM during the design phase to reap the benefits down the line. The sheer complexity of every high-rise building, with a myriad of details, means that this building type would likely benefit the most from the introduction of BIM. However, high-rise buildings can be broadly categorized into two groups: residential and commercial.

Residential high-rise buildings are primarily created for apartments and similar cases. In residential BIM high-rise construction projects, more emphasis is placed on the architectural aspects rather than the MEP (mechanical, electrical, and plumbing) aspects. Since the design phase is the most active phase for the architectural tasks, this is where the influence of BIM becomes apparent, allowing for the creation of highly detailed 3D models of the entire structure down to the smallest object.

This model is used throughout the construction process, making it more valuable as a whole, as the same model is used for MEP design, clash detection, and other purposes, making construction faster and more efficient from the beginning. Even the latest projects in a building’s lifecycle can take advantage of a BIM model with features such as energy analysis, opening up more possibilities for building modification, maintenance, and even demolition.

Commercial BIM high-rise buildings, on the other hand, place more emphasis on MEP elements than on overall architecture, making every project even more complex than residential buildings. In these cases, the use of BIM is almost mandatory, as these structures are highly sophisticated and could benefit from any efficiency improvement they can get.

Several tasks are universal across both building types, such as cost estimation, quantity takeoff, element tracking and modification, scheduling, and linking 3D geometry and design documents. These tasks are known to be tedious and time-consuming, but proper BIM implementation can significantly improve them.

Using BIM for commercial high-rise building creation offers several advantages to contractors, including higher efficiency, lower construction costs, lower waste generation, and even higher-level tasks such as quantity takeoff, cost estimation, scheduling, and many others – industry experts refer to this as 4D BIM, 5D BIM, and so on.

However, the most significant advantage of BIM in this specific field is its ability to aid with workflow management. As every high-rise construction project is incredibly complex, any assistance with general management tasks for these projects is always beneficial. Here are some examples of how BIM can help high-rise building projects with workflow management:

• Easier communication across nations via widespread BIM usage
• Project documentation management automation
• Every single change to the 3D BIM model is immediately noticeable for every party involved in the process, drastically reducing miscommunication
• Automatic management of information stored in databases, such as metadata or the entire building model
• Easier review for every modification for better integrity and accuracy, and more

BIM in Tiefbau

There is a widespread misconception that BIM offers no benefits to any project types other than various architectural projects in civil engineering. There is also the misconception that BIM is only useful as a long-term solution, which is far from the truth. BIM can bring benefits shortly after its initial implementation, as there is no need for the complete implementation of the BIM method to work. Benefits such as error reduction, data sharing, collaboration, and centralized data sharing (using a BIM model as a CDE – Common Data Environment) can all be implemented and utilized separately much faster than the BIM method as a whole. This means that there are several different benefits that BIM can bring at different stages of implementation.

In reality, BIM can be beneficial to civil engineering projects, including tasks and projects not related to road construction. Below are several examples of BIM use cases for civil engineering.

BIM can simulate various situations effectively for civil engineering, including dynamic site analysis, sight distance analysis, flood simulations, and more. BIM can also speed up several cost-estimating processes with 5D BIM, a process of adding schedule and cost-related information to a BIM model, enabling it to perform various estimates automatically based on the entire data pool that the BIM model has.

Clash detection is another general BIM field that could prove extremely beneficial for civil engineering, as civil engineering projects consist of multiple different parts and objects that could potentially overlap. Detecting these issues early on allows contractors to perform fewer reworks during the construction phase, speeding up the overall project realization and improving project quality.

BIM can also be used for reality capturing in civil engineering, which is uncommon for architectural BIM projects. Since BIM works as a data aggregator, it can easily store and showcase large volumes of data related to reality capturing, such as GIS (geographic information system) data, raster data, and many others.

Unfortunately, BIM still faces several issues on its road to becoming a worldwide standard for construction, and several long-running issues in the construction industry stand in its way. One of the biggest issues is that BIM implementation still has to work based on existing VOB (Vergabe- und Vertragsordnung für Bauleistungen) regulations without implementing new ones, decreasing the capabilities of BIM as a whole significantly.

The main issue is that the most standard approach to construction in this industry is to award the construction work and planning work separately. This approach often leads to the planning part of the project only doing the bare minimum and then leaving every other task to the construction-related stakeholders. This greatly increases the amount of work that contractors have to do and can lead to delays, budget overruns, and other issues.

This is completely contradictory to some of the most basic principles of BIM – collaboration and cooperation from start to finish. Unfortunately, the current state of industry standards in Germany makes it challenging to implement BIM methods at their full scale. Not only would new laws and regulations need to be passed first, but some of the existing ones would also need to be modified, which is a far more challenging change for any country.

Conclusion

BIM is not just a model; it is an entirely different approach and method of project creation. These projects do not have to be solely architectural, either. Civil engineering, road construction, and high-rise buildings are just some examples of how versatile a BIM-centered approach can be. It can improve general efficiency, boost project realization speed, reduce costs, eliminate reworks, and more.

However, BIM as a comprehensive approach to construction projects also has its disadvantages. It puts a lot more pressure on the security aspect of a company’s information, and the administrative burden of BIM management is significantly higher than ever before. There is also the fact that a BIM implementation process has a rather steep upfront cost because the method requires project participants to be familiar with it to operate it to its fullest, which is where upfront training costs come in. Other issues include a wealth of different data formats in the industry that are rarely compatible, the overall conservative nature of the industry, and many other examples.

Building Information Modeling (BIM) as a whole represents a significant change to many different processes that the construction industry has used for decades. It is not particularly surprising that the adoption of BIM has not seen any drastic changes until government-level construction requirements begin to refer to BIM as a mandatory approach to construction, in order to improve project quality and reduce waste.

Although Germany may not be the first country to start adopting BIM as a recommendation for all construction industry players in specific fields, the fact that the process of adopting BIM has already begun is a good sign. It means that construction projects all over the country are only going to get better and better from now on.